 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
| PhotoKB HomeDiscussion Groups Digital Photography Digital PhotoDSLR CamerasZLR CamerasPoint & Shoot CamerasFilm Photography 35 mmLarge FormatMedium formatDarkroomFilm and LabsOther EquipmentPhoto Technique Nature PhotographyPeople PhotographyTechnique GeneralGeneral Photo Topics General TopicsAustralian PhotographyUK PhotographyDirectoryPhoto Clubs |
Photo Forum / Film Photography / Darkroom / July 2004Coffee as a document film developer
I won't post the image here, but you don't have to be a member or sign in to view the longer article, with scan, that I posted to photo.net. Short abstract: the "standard" coffee developer can be easily made up as a low contrast developer in the same class as POTA, Technidol, or TD-3 by reducing the developing agent (instant coffee, presumably by way of its content of caffeic acid, which is a catechol) while maintaining or increasing the alkali (washing soda, sodium carbonate monohydrate). Result is better perceived sharpness than HC-110 Dilution G, similar tone scale, and slight loss of toe speed, which may be recoverable by increasing alkali (to increase activity) and reducing agitation (to increase compensation). Grain remains too fine to detect with a 2400 ppi scanner -- as it should; Imagelink HQ should have grain too fine to detect at 4000 ppi. http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=008Gqd  SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. On 5/16/2004 2:19 PM Donald Qualls spake thus: > I won't post the image here, but you don't have to be a member or sign > in to view the longer article, with scan, that I posted to photo.net. [quoted text clipped - 12 lines] > > http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=008Gqd Hmm; can't say I'm all that impressed with that picture. How much of the frame is that? If it's only a small portion, then I'm more impressed. (I'm sure the slow shutter speed you used when shooting one moving vehicle from another didn't help much, either.) I am impressed that ordinary coffee, plus one other simple chemical, can be used to develop film at all. SignatureI was quickly apprised that an "RSS feed" was not, as I had naively imagined, some new and unspeakable form of sexual debauchery practised by young persons of dubious morality, but a way of providing news articles to the cybernetic publishing moguls of the World Wide Wait so they can fill the airwaves with even more useless drivel. - Cynical shop talk from comp.publish.prepress > On 5/16/2004 2:19 PM Donald Qualls spake thus: > [quoted text clipped - 4 lines] > (I'm sure the slow shutter speed you used when shooting one moving > vehicle from another didn't help much, either.) Yes, that's the complete 10x14 mm frame -- about 1/6 of a 35 mm frame. It's also a fixed focus (8 feet) lens, dependent on DOF to get infinity focus, they claim from f/5.6 on down to the smallest opening of f/11. Well, of course, DOF is just a measure of how out of focus we're willing to tolerate, and while a 2400 ppi scan is only about as harsh as a 3x4 print from this size negative, it's also at the extreme limit of my scanner's resolution (optically, it's 1200 ppi, but with microstepping I'm only interpolating in one direction to get 2400 ppi). The image I posted was reduced 50% after scanning, so is equivalent to 1200 ppi scan; pretty low resolution for such a small negative. And, as you say, moving vehicles and slow shutter don't help. > I am impressed that ordinary coffee, plus one other simple chemical, can > be used to develop film at all. I've done a couple rolls of Tri-X in the original Caffenol, which consists of 4 slightly rounded tsp of coffee crystals plus 2 level tsp of washing soda per 8 fluid ounces of water; aside from a strong general stain (acts as fog, more or less, and probably has some effect as a soft contrast filter on mulit-grade paper due to its color), the images are very reminiscent of Rodinal -- with no solvent action at all (no sulfite or other silver solvent chemicals like ammonia, ferricyanide, etc.) and a catechol developing agent (caffeic acid is the best candidate, AFAIK, and it's a catechol related to pyrocatechin), sharpness is very good and Tri-X develops at least full ISO speed, possibly 500 or 640 toe speed. I haven't detected any imagewise stain, but I'm using an acid fixer, which is said to reduce staining even by pryogallol developers like PMK. To me, with all the developer gyrations people go through to get any kind of pictorial image out of Tech Pan or microfilm (which are desirable in the first place for their incredibly fine grain, and in the case of microfilm because they come in 16 mm unperforated which is convenient for submini cameras like the Minolta 16 format), I was just very pleased to get an image with good gradation and speed on the first try with a new developer, especially one with no history of use with document films. No, it's not a very good image -- it's a pretty basic camera, I was hand holding while driving -- but I expect to get better from the Minolta 16 II (with its better and faster lens and faster shutter) and Copex Rapid (EI 100 instead of EI 50) I'm currently carrying, but it's one of the better ones I've had from that original model Minolta 16 with Imagelink HQ film. SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. On 5/16/2004 5:46 PM Donald Qualls spake thus: >> On 5/16/2004 2:19 PM Donald Qualls spake thus: >> [quoted text clipped - 9 lines] > contrast filter on mulit-grade paper due to its color), the images are > very reminiscent of Rodinal [...] I wonder: since the stain may be due to constituents of the coffee that have nothing to do with development, what if you were to use the active ingrediments only? Is caffeine the active agent? If so, one could use that instead and eliminate the staining. SignatureI was quickly apprised that an "RSS feed" was not, as I had naively imagined, some new and unspeakable form of sexual debauchery practised by young persons of dubious morality, but a way of providing news articles to the cybernetic publishing moguls of the World Wide Wait so they can fill the airwaves with even more useless drivel. - Cynical shop talk from comp.publish.prepress > On 5/16/2004 5:46 PM Donald Qualls spake thus: > [quoted text clipped - 16 lines] > ingrediments only? Is caffeine the active agent? If so, one could use > that instead and eliminate the staining. The best opinions at this point, from people who appear to know developer chemistry a lot better than I do, is that the (main) developing agent is caffeic acid, which despite the name (which more or less only means it's derived from coffee, though in fact it's found in a lot of green leaves in the precursor glycoside form) isn't at all closely related to caffeine (caffeic acid is a phenol, caffeine is an alkaloid). The general stain I've seen on Tri-X and that's been reported on Plus-X is believed to be due to tannins and/or lignins in the coffee, and unrelated to the developing action -- the lack of that stain in yesterday's microfilm batch supports that theory. There are probably a number of other phenols (especially benzopyrenes, relatives of both pyrogallol and metol) capable of developing an image that are present in coffee -- which has sometimes been described as containing all of organic chemistry in a cup -- but none are anywhere near the concentration of caffeic acid. Caffeic acid, as a close relative of pyrocatechin, probably *should* produce some imagewise stain, but fixing in an acid fixer (a commercial product that likely also contains sodium sulfite) is known to reduce staining from well known staining developers like PMK, Pyrocat HD, WD2D(+), and Rollo Pyro; acid fixers are the reason for the post-fix soak in the spent developer that's commonly recommended with these developers. Unfortunately, I'm a waste not, want not sort (mostly), and I have enough Ilford Rapid Fixer left, in working solution and concentrate, to last a couple years (though that will likely change when I start printing, as printing goes through fixer much more rapidly than film) -- that's unfortunate, because it means I won't be buying a bottle of TF-4 any time soon. It's also possible that Caffenol *does* produce imagewise stain, and I just don't have the equipment or knowledge to detect it; when I scanned Tri-X negatives developed in Caffenol as color negatives, there were distinct differences in the overall density of red, green, and blue (ascending density in that order), but that's what I'd expect with a simple filter overlaying the image, of the color of the general stain. There was no change in the shape of the histogram from one channel to the next. The individual channel images are hard to compare, because the filtering effect means the red will be too light if the blue is right, and the blue will be too dark if the red is right. The images always seem different -- blown highlights in red stay blown even when I lower the scan midpoint so far the blue image starts to look too dark -- but I don't have color scans of pyro negatives to compare against, most especially not with an overlying brown general stain. SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. > On 5/16/2004 2:19 PM Donald Qualls spake thus: > > I am impressed that ordinary coffee, plus one other simple chemical, can > be used to develop film at all. Here are a couple of my Tri-X images in original Caffenol, from 35 mm with a Spotmatic and Super Takumar f/1.4 50 mm lens. This is a 6 mm square crop at 2400 ppi, no resizing: http://www.photo.net/photodb/photo?photo_id=2316593&size=lg This is a full frame: http://www.photo.net/photodb/photo?photo_id=2316585&size=lg The full frame is resized to about 22% in each dimension from the original scan, in which you can count the white hairs along the edge of the black patch behind her eye. Much better camera and lens than the original Minolta 16 and Rokkor f/3.5 25 mm used with the Imagelink HQ example; makes a huge difference -- but notice the difference in grain as well. This kind of grain is generally unacceptable in a 10x14 mm negative. I really need to try Caffenol with some 9x12 cm Fomapan 100 -- grain should be nothing to worry about in that format, and the sharpness and speed gain would be worth something. SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. That's just amazing. An actual use for instant coffee. > I won't post the image here, but you don't have to be a member or sign > in to view the longer article, with scan, that I posted to photo.net. [quoted text clipped - 23 lines] > Opinions expressed are my own -- take them for what they're worth > and don't expect them to be perfect. "Gene Johnson" <genej2@cox.net> wrote in news:JGRpc.56085$iy5.31778 @okepread05: > That's just amazing. An actual use for instant coffee. LOL! Jorge > That's just amazing. An actual use for instant coffee. That's almost exactly what I said when I read the first posting on photo.net with images from Plus-X souped in Caffenol. I certainly don't consider instant coffee drinkable; I brew my java from whole beans ground when I set up the pot (the night before, on a timer, out of consideration for my alarm time). However, it's also interesting in terms of educational use; with today's liability environment, a developer that's safe to drink has to be worth something to teachers who want to teach darkroom photography without getting sued when little Kevin gets a rash that his parents think comes from the developer (and never mind the new detergent they just switched to, seven or eight different weeds growing through cracks in the pavement on the playground, or the eight other kids in his home room with the same rash who aren't taking photography). No, I wouldn't recommend drinking a sodium carbonate solution -- but it won't do any actual harm, other than inducing a mighty belch. And if little Kevin is allergic to coffee, better to find out when he's in grade school and hasn't started drinking the stuff. And I can't see any kid actually drinking enough of this stuff to do genuine harm -- it's abou four times normal coffee strength, and bitter as hell with the alkaline pH. Interestingly, the original Caffenol, with twice the coffee of the LC variety, smells very much like a day-old broiler pan with burned-on meat residue and fat; probably a coincidence of benzopyrenes. SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. Somebody is going to have to try this with Techpan. I don't shoot much TP, but it would be nice to have the developer for it available at the supermarket. I know a number of people who would be interested in this. 35mm techpan landscape shooters. They need all the help they can get :) Coffee is indeed wonderful stuff. I wonder if quality espresso would giver richer tones ? Gene > I won't post the image here, but you don't have to be a member or sign > in to view the longer article, with scan, that I posted to photo.net. [quoted text clipped - 23 lines] > Opinions expressed are my own -- take them for what they're worth > and don't expect them to be perfect. > Coffee is indeed wonderful stuff. I wonder if quality espresso would giver > richer tones ? > > Gene uhmm... as a good italian and photographerI feel like obliged to try a coffee developer? Sound interesting and smelling good!! :D BTW the post about the coffee developer sounds quite interesting!! Are italian llucky to have the best coffee (and developer..) of the world? CIAO!! Stefano SignatureNon ? bello cio che ? bello figuriamoci cio che ? brutto! On 5/17/2004 1:08 PM Stefano Bramato spake thus: >> Coffee is indeed wonderful stuff. I wonder if quality espresso would >> giver richer tones ? [quoted text clipped - 6 lines] > BTW the post about the coffee developer sounds quite interesting!! Are > italian llucky to have the best coffee (and developer..) of the world? Not necessarily; I think the Turks might have a thing or two to say about that. SignatureI was quickly apprised that an "RSS feed" was not, as I had naively imagined, some new and unspeakable form of sexual debauchery practised by young persons of dubious morality, but a way of providing news articles to the cybernetic publishing moguls of the World Wide Wait so they can fill the airwaves with even more useless drivel. - Cynical shop talk from comp.publish.prepress > Not necessarily; I think the Turks might have a thing or two to say about that. In Turkey they put too much sugar... and the only good thing is that this kind of coffe is sometimes a blend of various other aroms... In italy only grounded coffee, water, and a small qamount of sugar. Near the perfection!! ciao!! :d SignatureNon ? bello cio che ? bello figuriamoci cio che ? brutto! >> Not necessarily; I think the Turks might have a thing or two to say about that. > [quoted text clipped - 3 lines] >In italy only grounded coffee, water, and a small qamount of sugar. >Near the perfection!! Ahhh, CafFascismo! The Brasilians got it right. Their Robusta beans have more caffeine and, with a light American roast the natural sweetness is not baked away. Besides, it's the "regular" coffee inmost food stores here in the US and is inexpensive, as a result. Now, I do admit to appreciating Sumatra Mandheeling and the Mexican Finca Irlanda, too, but the Eight O'Clock coffee from the A&P suits me just fine, although I haven't used it as a developer yet. Just MHO. Robert Vervoordt, MFA Il computer puo essere un grande strumento, ma in mano a Robert Vervoordt sta a ved? che scrive sul niusgrup: > Ahhh, CafFascismo! don't try to write that word please in this ng please. I hate it in every form. > Just MHO. yes, just your opinion. AFAIK every country says that it's *the first* in something. Ok you prefer brasislian or american or mexican coffee. I prefer italian espresso. MAde by old italian coffee toaster. Simple. ciao SignatureNon ? bello cio che ? bello figuriamoci cio che ? brutto! >Il computer puo essere un grande strumento, ma in mano a Robert >Vervoordt sta a vedè che scrive sul niusgrup: [quoted text clipped - 3 lines] >don't try to write that word please in this ng please. >I hate it in every form. HMM, forgot the origin of the word, which is unfortunate. It has been in use for so long, now, as refernce to opinionated and assertive behavior, that I completely missed the dark origins. >> Just MHO. > [quoted text clipped - 3 lines] >I prefer italian espresso. MAde by old italian coffee toaster. >Simple. Not exactly simple. Here, in the metropolitan areas of the US, there is a tendency to promote burned coffee blends and, as in the case of Sterbucks to offer no real American roast blends. This was the behavior that led to my use of the F word. All that aside, it is true that Light rasts along with Robusta beans provide higher levels of Caffeine and, possibly other volatile components. I have to admit that that is really irrelevant for this thread, as the developer used by the original poster was not brewed from beans directly, but was made from instant coffee powder. Hope I corrected things. Robert Vervoordt, MFA AFAIK innstant cofee has a high proportion of robusta, since it's very cheap, and once one is prepared to dring brown hot water... (-: Jorge > All that aside, it is true that Light rasts along with Robusta beans > provide higher levels of Caffeine and, possibly other volatile [quoted text clipped - 7 lines] > > Robert Vervoordt, MFA On 5/18/2004 1:39 PM Robert Vervoordt spake thus: >>Il computer puo essere un grande strumento, ma in mano a Robert >>Vervoordt sta a vedè che scrive sul niusgrup: [quoted text clipped - 28 lines] > developer used by the original poster was not brewed from beans > directly, but was made from instant coffee powder. Actually, these seemingly rambling observations may not be all that unrelated to the subject under discussion. I prefer what some folks, yourself included, might consider "burnt" coffee, French roast to be exact. I like it because it doesn't have the sour taste present in more lightly-roasted coffees. I'm told this is due to the extended roasting "burning off" the acid which causes the sourness. And though I'm sure this is an imprecise description of what happens, chemically speaking (I don't think the acid actually gets "burned"), it does reduce the acid. Therefore, dark-roast coffees might be less suitable for use as developers, since the caffeic acid content might be reduced. SignatureI was quickly apprised that an "RSS feed" was not, as I had naively imagined, some new and unspeakable form of sexual debauchery practised by young persons of dubious morality, but a way of providing news articles to the cybernetic publishing moguls of the World Wide Wait so they can fill the airwaves with even more useless drivel. - Cynical shop talk from comp.publish.prepress Funny, but AFAIR the espressos I drunk in France were less roasted than the Italian ones, but I may be mixing channels... Jorge > Actually, these seemingly rambling observations may not be all that > unrelated to the subject under discussion. I prefer what some folks, [quoted text clipped - 7 lines] > for use as developers, since the caffeic acid content might be > reduced. >On 5/18/2004 1:39 PM Robert Vervoordt spake thus: > [quoted text clipped - 40 lines] >it does reduce the acid. Therefore, dark-roast coffees might be less suitable >for use as developers, since the caffeic acid content might be reduced. You're right about changes with heavy roasts beyond just a reduction in Caffeine. What those changes are, I have no idea. Jorge pointed out that the instants would most often contain Robusta because of its low cost. What they do to the various special varieties, again, I have no idea. I do remember someone making a developer from brewed Coffee. I think he used it as a semi stand developer as his timing was something like 9 hours, or overnight. His results were reminiscent of the Talking Dog, in that the big thing wasn't that he talked so well, but that he managed to talk at all. Donald's developer seems a great deal better than that. Robert Vervoordt, MFA > All that aside, it is true that Light rasts along with Robusta beans > provide higher levels of Caffeine and, possibly other volatile [quoted text clipped - 3 lines] > developer used by the original poster was not brewed from beans > directly, but was made from instant coffee powder. Not completely irrelevant, I think. Caffeic acid (the best candidate for the developer in Caffenol) is derived from a glycoside (a sugar side chain on the basic phenol chemical) that is present in many green leaves and fruits; in coffee, the conversion occurs in the roasting process, the same carmelization that turns the beans from green to brown (or black) breaks the sugar away from the caffeic acid. Further, instant coffees (at least as commonly sold in America) are usually made from mostly /robusta/ varieties with only enough /arabica/ beans to produce an acceptable flavor; /robusta/ comprise some 80% of the beans grown worldwide, most of which production goes to production of caffeine for addition to other products such as soft drinks and OTC medicines (No-Doz, Anacin, etc.). /Robusta/ is not commonly drunk by itself because it's difficult to roast well; I've read that the berries are too big, leading to burning the outer layers before the core is fully roasted; the /arabica/ that comprises every "varietal" coffee that you can buy in a coffee shop has the very small berries we're used to seeing in whole bean coffee. Caffeic acid should be present in both, but there is probably a point in roasting when all the glycoside has been converted and another when the heat begins to denature the caffeic acid (probably by driving off side chains, but eventually by fracturing the all-important benzene ring that makes phenols what they are). I don't know enough details of how /robusta/ beans are prepared for instant coffee to say which is better, but I can make a good guess that very dark roasts will have less caffeic acid than lighter roasts -- but green beans have very little. If /robusta/ is allowed to overroast a bit on the exterior in order to fully roast the core, the less expensive instant coffees, which use a higher proportion of /robusta/ beans, might well have less caffeic acid per teaspoon of instant than correspondingly more expensive, "premium" instants like Folger's. In addition, the process of converting beans to brewed coffee to instant may contribute; I've had a report on photo.net that an unreported German market instant coffee is less active than the Folger's and a copy of Folger's that have produced good results in America (the German coffee might also have some percentage of chicory, or even roasted grain, an adjunct that became popular in German coffee during the shortages of the Second World War). Even with American brands, however, those that are heat dehydrated might be expected to have reduced levels of caffeic acid compared to freeze-dried (Maxim brand) or cold sprayed (Folger's and other "crystal" types), due to heat denaturing of the caffeic acid. Much, much more testing is in order... SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. > [brewed coffee vs. instant] > Caffeic acid should be present in both, but there is probably a point in > roasting when all the glycoside has been converted and another when the [quoted text clipped - 9 lines] > per teaspoon of instant than correspondingly more expensive, "premium" > instants like Folger's. > In addition, the process of converting beans to brewed coffee to instant > may contribute; I've had a report on photo.net that an unreported German [quoted text clipped - 3 lines] > adjunct that became popular in German coffee during the shortages of the > Second World War). Instand-drinks containing chicory or roasted grain are clearly labeled as such. German laws are very strict on things like food. The german coffe I used was "Granarom Gold Supreme Quality Coffee". As the name said a no-name brand "Made in Germany" for Lidl - a supermarket chain. It lists "100% ARABICA" which - following your explanation, may be the reason why it's less active than the ones you tried. > Even with American brands, however, those that are > heat dehydrated might be expected to have reduced levels of caffeic acid > compared to freeze-dried (Maxim brand) or cold sprayed (Folger's and > other "crystal" types), due to heat denaturing of the caffeic acid. > Much, much more testing is in order... As I said on photo.net I will order new chemicals in the next days and I saw caffeic acid (3,4-Dihydroxyzimtacid) listed. Do you know how much caffeic acid is in normal instant coffee? I don't need a exact number, only a range (is it 5mg, 10mg, 100mg, or 1g per liter) so I can guess how much I would need to do 3 test-rolls or so. It's not cheap and when I need more than 0.5g or 0.7g/liter I'll not order it. Christian > As I said on photo.net I will order new chemicals in the next days > and I saw caffeic acid (3,4-Dihydroxyzimtacid) listed. Do you know [quoted text clipped - 3 lines] > It's not cheap and when I need more than 0.5g or 0.7g/liter I'll not > order it. I posted something about this on photo.net, too, but if I read it right, /robusta/ beans would produce around 1 g/L in drip brewed coffee at 1 tb grounds per cup; regular Caffenol is at least three times brewed strength, possibly four times, so it'd be close to 4 g/L with Caffenol LC at 2 g/L. That figure, however, includes the chlorogenic acid, the glycoside precursor of caffeic acid; it might in fact be more active in this situation than caffeic acid (I was aware of it, and I've been told it may be a developer, just didn't realize there was that much in the coffee after ripening, drying, and roasting until today's research). The only way to be certain which agent is doing the work (or if more than one are involved) will be to test with the individual chemicals -- caffeic acid, chlorogenic acid, even caffeine itself (which some authors state as the primary developer in coffee) -- but as you say, individual organics extracted from plant material, rather than synthesized in bulk for industry, are expensive (except caffeine, which is the very first thing to dissolve out of coffee -- hence the water process for decaffination). SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. Executive Summary: Starting with espresso one can make caffenol at a 1:2 dilution. Drip coffee is right out. * * * "Donald Qualls" <silent1@ix.netcom.com> wrote > Robusta ... 1 g caffeic acid/L drip brewed coffee at 1 tb coffee / cup Caffeic acid: 1L/g * 16c/L * 1Tb/c => 16Tb coffee/g caffeic acid > Caffenol is at least three times brewed > strength, possibly four times Caffenol: 1g/L * 4 => 4g caffeic acid / L caffenol Ground coffee required for 1 liter of caffenol: 4g/L * 16Tb/g => 64Tb ground coffee / Litre of caffenol Per 35mm roll -> 8 oz caffenol: 8oz * 0.0338 L/oz * 64Tb/L => 17.3 Tb ground coffee 17.3Tb * 1c/16Tb => 1.08 c ground coffee Let us say 1 cup of grounds + 1 cup of water + xx other chemicals => 8 oz of caffenol A drip coffee maker will not work. A good percentage of the caffeic acid will remain in the grounds as the concentration of caffeic acid in the coffee is about (waving of hands) the same as the concentration in the grounds. Further ... espresso is: 7g coffee / 2oz espresso * 1 oz / 0.0338 L => 104g ground coffee /L The density of coffee (Maxwell House "Colombian Supreme") is: 33 oz.wgt coffee / cylinder 6" dia * 6" high => 0.195 oz.wgt / in^3 0.195 oz.wgt/in^3 * 28.35 g/oz.wt * in^3/1.11Tb => 4.97 g coffee/Tb Yielding, for espresso: 104g coffee/L (espresso) * 1 Tb/4.97g coffee => 20.9 Tb coffee/Litre Conclusion: To make caffenol one needs coffee brewed at 64Tb ground coffee / Litre of water Espresso is brewed at only 20.9 Tb/L So much for using coffee to make caffenol -- though espresso can be used at 1:2. I'm sure there is a faster way to make the calculation, the above is a 'stream of (un)consciousness calculation'. SignatureNicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. > Executive Summary: Starting with espresso one can make caffenol at > a 1:2 dilution. Drip coffee is right out. [quoted text clipped - 8 lines] > > 1L/g * 16c/L * 1Tb/c => 16Tb coffee/g caffeic acid Wups, stop right there -- 16 c is a gallon, not a liter. That's nearly a factor of four all the way down from here, suggesting that instead of 64 T per liter of coffee, you would need only 16 T per liter; my normal brew strength is close to that (8 T per pint -- I like my coffee with character). >>Caffenol is at least three times brewed >>strength, possibly four times [quoted text clipped - 20 lines] > of caffeic acid in the coffee is about (waving of hands) > the same as the concentration in the grounds. Above original figure was for brewed coffee at regular strength, and already accounts for solubility limitations. Double the grounds, you'll double the caffeic acid, near enough. Quadruple the grounds, you'll probably get a little less than 4x the caffeic acid, if only because it'll be hard to extract the coffee uniformly. > Further ... espresso is: > > 7g coffee / 2oz espresso * 1 oz / 0.0338 L => 104g ground coffee /L My espresso shots are marked at 1.5 ounces -- though in fact I usually do brew to 2 ounces. Each espresso scoop is 2 level T; that means espresso (at least in my house) is actually brewed to 4x my (strong) drip coffee strength, or about 32 T per liter -- twice what's necessary for Caffenol, after accounting for the unit conversion error above. SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. > Nicholas O. Lindan wrote: > > Caffeic acid: > > > > 1L/g * 16c/L * 1Tb/c => 16Tb coffee/g caffeic acid > > Wups, stop right there -- 16 c is a gallon, not a liter. Ooops. I think I failed the mid-term.... Corrected: Summary: Brew coffee at 4tb/cup for caffenol. * * * Caffeic acid: 1L/g * ~4c/L * 1Tb/c => ~4Tb coffee/g caffeic acid > Caffenol is at least three times brewed > strength, possibly four times Caffenol: 1g/L * 4 => 4g caffeic acid / L caffenol Ground coffee required for 1 liter of caffenol: 4g/L * 4Tb/g => 16Tb ground coffee / Litre of caffenol One 35mm roll requires 8 oz (1 cup) caffenol: 8oz * 0.0338 L/oz * 16Tb/L => 4.3 Tb ground coffee (Revised) Conclusion: My morning coffee should work about right. SignatureNicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. Remove spaces etc. to reply: n o lindan at net com dot com psst.. want to buy an f-stop timer? nolindan.com/da/fstop/ Now that you guys have your caffeic acid concentration in Caffenol worked out (4g/L if I'm reading this right) you might want to see how it compares to catechol (aka "pyrocatechol")-containing developers. Use an molecular weight ratio of caffeic acid : catechol = 18:11 so if we assume that the caffeic acid has the same activity on a per-mole basis as catechol does, this is like having a developer with about 2.4 g/L of catechol. How much do developers like Pyrocat-HD use? Jordan >>>Caffeic acid: >>> [quoted text clipped - 32 lines] > > My morning coffee should work about right. Jordan Would it be sensible to do such a compare? Pirocat-HD is a superaddictive pair of phenidone-cathecol. Is there some cathecol only dev? Jorge > Now that you guys have your caffeic acid concentration in Caffenol > worked out (4g/L if I'm reading this right) you might want to see how [quoted text clipped - 5 lines] > > Jordan > Now that you guys have your caffeic acid concentration in Caffenol > worked out (4g/L if I'm reading this right) you might want to see how it [quoted text clipped - 3 lines] > as catechol does, this is like having a developer with about 2.4 g/L of > catechol. How much do developers like Pyrocat-HD use? I can't answer for Pyrocat HD, but according to Anchell & Troop you can make a low contrast developer (like Caffenol LC) with 0.15 to 0.30 g/L pyrocatechin; they also give (p. 81) experimental pyrocatechin developers for normal contrast containing from 0.5 to 2.0 g/L of pyrocatechin. It should be noted here, however, that my post a couple days ago concerning level of caffeic acid actually gave chlorogenic acid -- which is (I'm told) probably also a developer, since it's a glycoside version of caffeic acid (has a sugar of some sort as a side chain), but may be more or less active than caffeic acid; the actual caffeic acid figure wasn't given in the reference I found. I would expect the levels to be related, since caffeic acid is derived from chlorogenic acid in drying and roasting -- and I was at that time making the point that /robusta/ beans contain up to twice as much active whatever as /arabica/ varieties. Still, the activity I get with Caffenol LC is very similar in rate and end result to HC-110 Dilution G (1:29 from stock solution), which leads me to believe that the quantities of active developer you suggest above aren't far wrong -- in turn strongly implying that both caffeic acid and chlorogenic acid are at work. Regular Caffenol is slightly less active than HC-110 Dilution H (1:15 from stock solution), which again fits with the above figures. It seems reasonable to suppose that caffeic and/or chlorogenic acids are a little less active, gram for gram, than pyrocatechin; that would fit with developer activity approximately equating 2+ g/L of coffee acids to 0.5 g/L of pyrocatechin. Alternately, chlorogenic acid may be contributing little or nothing, and the level of caffeic acid might be 1/4 that of chlorogenic with caffeic acid similar in activity to pyrocatechin -- without testing the individual compounds, it's impossible to say. Further complicating matters, other compounds in the coffee may act as restrainers (sugars are known to do this, and there are sugars of various sorts in various states of carmelization in coffee); I do note that aside from the brown tannin stain, there appears to be very little fog with Caffenol and effectively none (nor any notable tannin stain) with Caffenol LC; given the amount of carbonate, however, the slow working may just be due to insufficient alkalinity, which would also keep fog down. It might be worth trying Caffenol with 25% more carbonate to see if development can be accelerated without adding too much fog. SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. In the photo-net discussion of caffenol Donald Qualls wrote: > And the aroma of the coffee developer, which is almost identical > to that of a broiler pan twelve hours after grilling a steak, > suggests that there are benzopyrenes present in coffee That begs the question: can one develop film in an old, uncleaned, broiler pan? I think I know what's for dinner tonight. SignatureNicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. Remove spaces etc. to reply: n o lindan at net com dot com >> In the photo-net discussion of caffenol Donald Qualls wrote: > [quoted text clipped - 6 lines] >> >> I think I know what's for dinner tonight. :) It's certainly possible there may be developing agents present, though I think it would be more productive to try making a sort of broth from overroasted, very lean meat (fat won't do your film any good at all). Something along these lines: broil thin steaks until black, turning as needed to cook evenly. Transfer steaks and scrape as much residue from broiler pan as possible, into glass stock pot, cover with distilled water, and simmer for twelve hours, adding distilled water as needed to keep covered; use only wood or plastic utensils (stainless steel okay). Remove all solids and reduce to 1/4 volume, filter and treat as coffee for film developer tests. Seems an expensive waste of good meat to me, though. SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. > Nicholas O. Lindan wrote: > > In the photo-net discussion of caffenol Donald Qualls wrote: > > > And the aroma of the coffee developer, which is almost identical > > > to that of a broiler pan twelve hours after grilling a steak, > > > suggests that there are benzopyrenes present in coffee Adding alkali to most any food makes it smell and taste awful. Adding some baking soda to cooked meat makes it smell (and maybe taste, I never got that far) of a dying tidepool. > > That begs the question: can one develop film in an old, uncleaned, > > broiler pan? > overroasted, very lean meat ... broil thin steaks until black, > turning as needed to cook [sic] evenly[?]. Transfer steaks and [quoted text clipped - 8 lines] > > Seems an expensive waste of good meat to me, though. Dead straight. So I am not going to do it that way. The recipe will be: 1.5" Prime Angus Porterhouse, marinated in Madeira and Worcestershire sauce [did you know Woosy sauce is made from fermented anchovies?] while my stomach is marinated in Jameson. The steak is then rubbed with garlic, pepper and sage, broiled for 3 minutes on each side and served with white asparagus, thin sliced fried potatoes and a slightly warmed bottle of Chateau Margaux. The dirty dishes and pans will go into the sink to soak overnight along with the film. SignatureNicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. Remove spaces etc. to reply: n o lindan at net com dot com psst.. want to buy an f-stop timer? nolindan.com/da/fstop/ Another alternative I have wanted to try is dirt, dirt being a sort of 'universal' chemical containing most anything. I think I will contact expose a frame of 35mm and stand develop it in a black 35mm film can filled 1/2&1/2 with dirt and water. I wonder if it will work as a one-shot? SignatureNicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. Remove spaces etc. to reply: n o lindan at net com dot com > Another alternative I have wanted to try is dirt, dirt being > a sort of 'universal' chemical containing most anything. [quoted text clipped - 3 lines] > > I wonder if it will work as a one-shot? I'd be amazed if you get anything; dirt contains a plethora of salts, but not all that much organic material in most cases, and it's organics (specifically phenols, in almost all cases) that act as developing agents. If you were to use compost directly from the compost heap, you'd have a better chance, especially if the bulk of the material was grass and green leaves; both contain significant levels of chlorogenic acid. SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. > I'd be amazed if you get anything; dirt contains a plethora of salts, > but not all that much organic material ... Someone needs to mulch their garden ... and get a dog ... I am using a well mulched and composted garden soil and adding some potting compound to the mix for extra bouquet. I am letting it stand develop for 24hrs. SignatureNicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. Remove spaces etc. to reply: n o lindan at net com dot com psst.. want to buy an f-stop timer? nolindan.com/da/fstop/ >>I'd be amazed if you get anything; dirt contains a plethora of salts, >>but not all that much organic material ... [quoted text clipped - 5 lines] > > I am letting it stand develop for 24hrs. Okay, with this and the meat experiment, one also needs to remember that while there are a plethora of compounds that will reduce silver halides to metallic silver, only a very small subset are selective enough to form an image from exposed halide and leave the unexposed material alone. Even if your potting soil soup turns film black, you haven't verified it will develop an image. BTW, my goal with garden, and especialy lawn, is minimal maintenance. I don't water, I don't fertilize -- and I don't much like dogs. The roses don't care, neither do the tulips and daffodils; pretty much anything else, I'm required to mow every week or two, and would as soon replace with concrete. SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. > Okay, with this and the meat experiment, one also needs to remember that > while there are a plethora of compounds that will reduce silver halides > to metallic silver, only a very small subset are selective enough to > form an image from exposed halide and leave the unexposed material > alone. Even if your potting soil soup turns film black, you haven't > verified it will develop an image. Lighten up, it's all in jest: what with coffee, mint leaves, green tea, extract of uncleaned oven .... Look I am not being very serious here ... love your lawn ... and I agree, fertilizing it just makes it grow. The tomato patch, however, is a different story. FWIW: 1) Extract of Tomato Patch did zilch in a 24-hour period. TMX @ ASA100. 2) The results of coffee - 1 cup water in Braun coffee maker - 4Tb/c. Kirkland (Costco) Colombian - 2 tsp A&H Washing Soda - TMX 100 - exposed at 100 - Stand developed 20min @ 80F - Normal fix et. al. Very thin negative, brown image, good shadow detail and lots of fog: Visual Blu Grn Red B+F .65od .72 .69 .55 Highlights 1.02 1.17 1.09 .87 Stand developing is not recommended, negs have _lots_ of bromide drag from the sprocket holes. 2) Conventionally processed TMX when soaked in above developer stained slightly, B+F values: Untreated .29 .24 .29 .26 Caffenol soak .30 .30 .32 .27 So, it seems the stain _is_ associated with the developing action. 3) Trying salt & sulfite as a fixing agent. In 24Hr the film is clearer but not fixed. I have not verified that undissolved silver is being dissolved. SignatureNicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. Remove spaces etc. to reply: n o lindan at net com dot com psst.. want to buy an f-stop timer? nolindan.com/da/fstop/ >>Okay, with this and the meat experiment, one also needs to remember that >>while there are a plethora of compounds that will reduce silver halides [quoted text clipped - 7 lines] > love your lawn ... and I agree, fertilizing it just makes it grow. > The tomato patch, however, is a different story. What, you never heard of a straight man? ;) > FWIW: > > 1) Extract of Tomato Patch did zilch in a 24-hour period. TMX @ ASA100. Pretty much as expected... :P > 2) The results of coffee > - 1 cup water in Braun coffee maker [quoted text clipped - 13 lines] > Stand developing is not recommended, negs have _lots_ of bromide drag > from the sprocket holes. Your dev time on this is on the short side anyway; with agitation 10-15 seconds every minute, I've been giving Tri-X 30 minutes at 72 F, which is close to your time after correcting for temperature, but reduced agitation reduces contrast. Try again, same conditions, with agitation every minute (or even constant agitation in a rotary probably wouldn't hurt), you'll get better contrast without any more base stain. Interesting to see different contrast levels in the color channels, though -- I couldn't be sure what I was seeing using my scanner to try to extract this information. I wonder how this will offset against the minus-blue nature of the base stain reducing contrast on VC printing paper? > 2) Conventionally processed TMX when soaked in above developer > stained slightly, B+F values: [quoted text clipped - 3 lines] > > So, it seems the stain _is_ associated with the developing action. Very cool indeed -- pyro in the coffee aisle! ;) > 3) Trying salt & sulfite as a fixing agent. In 24Hr the film is clearer > but not fixed. I have not verified that undissolved silver is being > dissolved. Sulfite alone has been reported to act as a fixer, but it may require a) a very strong solution (200 g/L is the strongest I've managed to make with water around 120 F), and b) multiple baths due to limited capacity. If the film is clearing, then the halide is being taken up, but 24 hours for partial fixing is a little excessive. I'm very inclined to think the capacity is so limited as to require multiple baths. I'd also be tempted to try a mixture of sulfite and ammonium hydroxide (i.e. clear household ammonia); ammonia is reported to promote solvent action, and might make the sulfite active enough to fix in a reasonable time. Salt has less effect, based on my reading. Maybe I'll get a chance to try it today; heaven knows I have some leader clips around... ;) SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. > Nicholas O. Lindan wrote: > > > Okay, with this and the meat experiment > > ... extract of uncleaned oven .... Look I am not being very serious here ... > What, you never heard of a straight man? ;) Yeah, and they're all bent. > > 2) The results of coffee > > V B G R > > B+F .65od .72 .69 .55 > > Highlights 1.02 1.17 1.09 .87 > Interesting to see different contrast levels in the color channels, Well, it is a brown stain and brown is a low value yellow. Increased density in the blue transmission is ratiometrically (sp?) equivalent to decreased density in the yellow. And can be described as the yellow stain absorbing blue light. > ... I couldn't be sure what I was seeing using my scanner to try > to extract this information. > > ... it seems the stain _is_ associated with the developing action. > > Very cool indeed -- pyro in the coffee aisle! ;) Follow up: bleached 1/2 the negative in ferri. The silver goes first but the stain follows soon after. I can't say the stain is separate from the silver. > > 3) Trying salt & sulfite as a fixing agent. In 24Hr the film is clearer > > but not fixed. I have not verified that undissolved silver is being [quoted text clipped - 3 lines] > a very strong solution (200 g/L is the strongest I've managed to make > with water around 120 F), and b) multiple baths due to limited capacity. 1 35mm frame in 8oz, saturated solution: sulfite sitting on the bottom of the graduate. > If the film is clearing, then the halide is being taken up, It can be bleaching.... > but 24 hours for partial fixing is a little excessive. Practicality? We don' need no steenkin' practicality.... Ever see the movie 'The Killing Fields' - in one scene two press photogs are trying to develop a passport photo in the sink. They can get it to develop but not fix - every time they turn on the lights the print turns slowly black. So, if I ever get stuck in an embassy in a war zone and need to forge an extra passport: I'm prepared! > I'd also be tempted to try a mixture of sulfite and ammonium hydroxide That was my next thought.... > (i.e. clear household ammonia); ammonia is reported to promote solvent > action, and might make the sulfite active enough to fix in a reasonable > time. Salt has less effect, based on my reading. Maybe I'll get a > chance to try it today; heaven knows I have some leader clips around... ;) As Toad (would have) said: "There is nothing - absolutely nothing - half so much worth doing as simply messing about in the darkroom." Though, personally, I'd go for the boats and leave the Toad in the hole. SignatureNicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. Remove spaces etc. to reply: n o lindan at net com dot com psst.. want to buy an f-stop timer? nolindan.com/da/fstop/ >>>2) The results of coffee >>> V B G R [quoted text clipped - 7 lines] > to decreased density in the yellow. And can be described as the yellow > stain absorbing blue light. Well, yes -- yellow is the opposite of blue, at least in terms of color channels -- if you do a CMY decomposition of a color negative scan, you get three grayscale positives corrsponding, in order, to Red, Green, and Blue (at least with my software). I guess I should have wondered why the red channel in an inverted scan (which, opposite cyan, would correspond most closely to the blue in the negative) had highlights that stayed blown even when I set the scan brightness so low the other channels started to degrade, while green (opposite magenta) was less affected and blue (opposite yellow, which contains no blue light) least of all. >>>... it seems the stain _is_ associated with the developing action. >> [quoted text clipped - 3 lines] > but the stain follows soon after. I can't say the stain is separate > from the silver. I don't know what happens when you bleach a pyro or pyrocat negative -- does the stain stay, or does it bleach too? And why would it matter if the stain is separate from the silver, as long as it's imagewise? BTW, I have an idea why we're getting so much background stain and fog, and I don't think it's just tannin staining; I think we're just plain getting fogging from something in the coffee that's not selective enough -- but it's not happening on microfilm; neither Kodak Imagelink HQ nor Agfa Copex Rapid developed in Caffenol LC shows the general stain or fog, though both show a brown tinted image, suggesting they did get imagewise stain; main difference is the lower concentration of coffee in the LC version of the developer. Of course, lowering the coffee would put us into the 45 minute time frame for normal contrast from Plus-X or Tri-X. And any restrainer we add will hurt the film speed and sharpness. >>If the film is clearing, then the halide is being taken up, > > It can be bleaching.... I guess that depends whether it's developed or you're just fixing out a piece of leader. Sulfite bleaches a little, but I've read that it has less bleaching action relative to its fixing than thiosulfates do. >>but 24 hours for partial fixing is a little excessive. > > Practicality? We don' need no steenkin' practicality.... Well, it depends what we're after with this... > Ever see the movie 'The Killing Fields' - in one scene two press photogs > are trying to develop a passport photo in the sink. They can get it to > develop but not fix - every time they turn on the lights the print turns > slowly black. So, if I ever get stuck in an embassy in a war zone > and need to forge an extra passport: I'm prepared! Can't say I have, but I can relate. Developing is easy, especially if you know about Caffenol (in a pinch you could use a tiny bit of sodium hydroxide as alkali instead of sodium carbonate, probably about 1/4 as much or a little less). Water makes a fine stop bath. But unless you can get the print fixed, it'll turn gray or brown over a space of hours (though more slowly if you get it really dry before turning on the lights). Say, if you have a method of bleaching, but no fix, you could make a reversal positive that wouldn't print out (I think): Exposed and develop normally. Bleach, clear, and wash. Reversal expose (just turn on the lights), redevelop to completion, and wash. There'll still be a tiny bit of residual halide that will print out, but it'll be small enough that the effect would look, at worst, more like a muddy print than like silvering or solarization. I'll have to try this when I get the rest of the stuff for printing; start with a paper negative exposed in one of my plate cameras. :) >>I'd also be tempted to try a mixture of sulfite and ammonium hydroxide > [quoted text clipped - 9 lines] > > Though, personally, I'd go for the boats and leave the Toad in the hole. Boats, schmoats -- I can't afford boats, but I can afford photography, at least done my way. :) Well, I could probably afford to do boats my way, too -- maybe after I quit having to spend money on my photo setup, $10 here, $20 there... SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. > 3) Trying salt & sulfite as a fixing agent. In 24Hr the film is clearer > but not fixed. I have not verified that undissolved silver is being > dissolved. Fixer seems to be the only substance that can't be readily found in a household. Also, you could place something copper(penny) in the fixer to see if it is dissolving the silver. If the penny coated in silver, it works! >>3) Trying salt & sulfite as a fixing agent. In 24Hr the film is clearer >> but not fixed. I have not verified that undissolved silver is being [quoted text clipped - 5 lines] > Also, you could place something copper(penny) in the fixer to see if > it is dissolving the silver. If the penny coated in silver, it works! Problem with that is that it would react the same in bleach -- the classic reaction that plates silver onto copper, in fact, is from silver nitrate solution. Any acidic solution containing silver ions will react this way, including sulfate, acetate, etc. The only verification of fixing is to clear the film, and sulfite does this only weakly and slowly; it appears it may require multiple baths to reduce halide in the film to acceptable levels within the capacity of a sulfite fixer. SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. > "Nicholas O. Lindan" <see@sig.com> wrote > > 3) Trying salt & sulfite as a fixing agent. In 24Hr the film is clearer > > but not fixed. I have not verified that undissolved silver is being > > dissolved. > > Fixer [thiosulfate] seems to be the only substance that can't be readily > found in a household. Household chemicals can be used, but I can't say I would recommend it. With the thin negatives obtained from a breakfast coffee & washing soda developer the results would be almost but not quite usable. Report: TMAX-100 - Fixing for 1 week in a saturated sulfite and salt solution: * Film exposed to light * Developer applied in a drop pattern to create areas of varying density. * Developer rinsed off under running water. * Film curled into a small glass beaker filled with salt and sulfite soln. at saturation concentration. * Left to stand in interrupted darkness for one week, rinsed clean * Film is clear enough to print. Base is sort of cloudy pink at ~.8od * The black spots are still there and don't look etched away * * * * Film curled into beaker and beaker 1/2 filled with Dektol 1:2 * Left for a week with lights on * Developed part has an overall grey fog - still printable. Base is ~1 od, spots still there * Undeveloped film looks the same as before development, ~.8od Conclusion: Salt & sulfite will act as a fixer of last resort. Problem is base fog. Suggestions for further mucking about: Ammonia and salt Vinegar, salt and sulfite Very dilute clorox - does it differentially remove developed/undeveloped silver? SignatureNicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. > Report: > [quoted text clipped - 14 lines] > > * The black spots are still there and don't look etched away The pink color in T-Max film is indicative that fixing hasn't completed (it's a sensitizing dye that's bound to the halide, and washes out when the halide is fully fixed); the high iodide content of this film makes it difficult to fix, and rapid fixers are recommended over traditional hypo fixers because of extremely limited capacity (like 2-3 films per liter, if even that) due to iodide build up. The same might be occurring with sulfite, potentially requiring a second fix step. > * * * > [quoted text clipped - 6 lines] > > * Undeveloped film looks the same as before development, ~.8od What you've done here is finish developing the unfixed halide -- strong indication that the previous treatment did not fully fix the film. > Conclusion: Salt & sulfite will act as a fixer of last resort. > Problem is base fog. This would probably be improved by treating for 1-3 days, changing for fresh solution, and treating another 1-3 days. And I doubt the salt is doing anything; the sulfite is probably the actor here. > Suggestions for further mucking about: > > Ammonia and salt > > Vinegar, salt and sulfite Ammonia and sulfite would be my next try. > Very dilute clorox - does it differentially remove > developed/undeveloped silver? Sodium hypochlorite is reputed to be a halide solvent, but bleach in useful strength will completely remove the emulsion from film. SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. >> Report: >> [quoted text clipped - 23 lines] > liter, if even that) due to iodide build up. The same might be > occurring with sulfite, potentially requiring a second fix step. Kodak always told me this was due to an anti-halation dye in the backlayers and it was cancelled by a certain pH. I thought that sensitising dyes were a) not bound to halides at all, just 'acting in the presence of' b) in such tiny concentrations you would not be able to detect them visually, especially after washing. But I may be wrongly informed. David > Kodak always told me this was due to an anti-halation dye in the > backlayers and it was cancelled by a certain pH. I thought that [quoted text clipped - 3 lines] > > But I may be wrongly informed. I'm basing my comments on comments I've read from Rowland Mowrey, who used to be a chemist for Kodak -- but I don't know that he worked directly with T-Max films, so can't say how "primary" a source he is. I do know that adequate fixing generally removes the dye, while nearly exhausted fixer will leave it, and that (much more acid) stop bath doesn't seem to touch it, while (alkaline) developers mixed from concentrate fresh for each session seem to make little difference -- same dev will give pink negs one time and not the next, while fresh fixer will alway remove the pink. There are two dyes involved here, BTW -- there's the dye that commonly comes off in the dev or presoak, turns it purple, and there's the faint pink to purple color that's left in the film after processing; the stuff that comes off in the first liquid is antihalation, as I understand it; what's left in the film after fixing and washing is sensitizing and/or panchromatizing dye related to incomplete fixing. Or that's the way I understand it, based on my reading of Mowrey's posts on photo.net. SignatureI may be a scwewy wabbit, but I'm not going to Alcatwaz! -- E. J. Fudd, 1954 Donald Qualls, aka The Silent Observer Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm Opinions expressed are my own -- take them for what they're worth and don't expect them to be perfect. >> Kodak always told me this was due to an anti-halation dye in the >> backlayers and it was cancelled by a certain pH. I thought that [quoted text clipped - 21 lines] > panchromatizing dye related to incomplete fixing. Or that's the way I > understand it, based on my reading of Mowrey's posts on photo.net. I think it would be possible since T-Max is a superpanchromatic film - sensitised differently to normal pan, with a higher red response and further into the far red too. Not as extreme as Ilford SFX but different from Tri-X etc. Maybe this does use a high level of sensitising dye which is enough to be visible. It would explain my own past confusion over why some film processing appeared to clear the film to 'grey white' and some left it pinkish. David > the high iodide content of this film makes > it difficult to fix, I think more costly a better way of putting it. > and rapid fixers are recommended over traditional > hypo fixers because of extremely limited capacity (like 2-3 films > per liter, if even that) due to iodide build up. Anchell & Troop are usually the quoted source for that opinion. In a manner of speaking they are correct. It should be kept in mind that it is the thiosulfate which does the fixing and that is a quantitative process, ammonium or sodium. Dan >>the high iodide content of this film makes >>it difficult to fix, [quoted text clipped - 9 lines] > that it is the thiosulfate which does the fixing and that is a > quantitative process, ammonium or sodium. Aren't most rapid fixers ammonium thiocyanate instead? I seem to think the fix we had for lith (imagesetting IR) film used to be. I always used that stuff for all my films since it was cheap and always around. It fixed very quickly - T-Max or anything going. David > Aren't most rapid fixers ammonium thiocyanate instead? I seem to think > the fix we had for lith (imagesetting IR) film used to be. I always used > that stuff for all my films since it was cheap and always around. It > fixed very quickly - T-Max or anything going. Rapid fixers are ammonium thiosulfate. Where iodide is involved the capacity of the sodium or ammonium form are very nearly equall. I think the speed of fixing is also about the same. The reason being ammonia has extremly little grip on silver in the presence of iodide. As I understand it, due to ammonia's loose grip on silver in the presence of any halide compared with thiosulfate's grip, a stealing action on the part of the thiosulfate ensues. So the thiosulfate loads up on silver. The ammonia acts as a carrier and with chloride and/or bromide present it will complex to some small extent. Dan >>Aren't most rapid fixers ammonium thiocyanate instead? I seem to think >>the fix we had for lith (imagesetting IR) film used to be. I always used [quoted text clipped - 10 lines] > loads up on silver. The ammonia acts as a carrier and with chloride > and/or bromide present it will complex to some small extent. I know the old Amfix etc used to be but the COSSH sheets (chemical statutory warning material) on our modern rapid fixers stated thiocyanate as the main component now. Mind you these are fixers which can clear a high silver content infra-red emulsion in 15 seconds. David >> Aren't most rapid fixers ammonium thiocyanate instead? I seem to think >> the fix we had for lith (imagesetting IR) film used to be. I always used [quoted text clipped - 10 lines] >loads up on silver. The ammonia acts as a carrier and with chloride >and/or bromide present it will complex to some small extent. Dan jun904 from Lloyd Erlick, Thiocyanates are a lot more expensive than either sodium or ammonium thiosulfate. I believe a large part of the reason is that thiosulfates are used in municipal water treatment plants. (Thiosulfates are sometimes referred to as 'anti-chlor' (for chlorine), so this may be a hint as to its use in water treatment). Mountains of sodium thiosulfate are imported to any large metropolitan area. Photography is a flea on this mountain. Or maybe a mosquito; all I know is it's summer and I'm itching. The thiocyanate fixers under discussion here sound like specialized materials (for fixing infra red imagesetting materials, perhaps...). I've completely stopped using ammonium thiosulfate fixer. I don't even have any in my darkroom any more. My initial reason for banning it was the stench. The rock hard deposits that resulted from a splash or dribble in the sink were enough for me, too. And I'm delighted to no longer be carrying those jugs it comes in, or disposing of them later. I use sodium thiosulfate fixer exclusively now. The so-called detriment of having a lower capacity is actually an advantage. Ammonium fixers claim such a high capacity that low volume film users like me can never use it all (I only process ten rolls at a time, occasionally twenty. I think my highest ever was a little over a hundred 120 format rolls in a month). The result is that film gets dumped into old, partly used fixer. Who knows how long that fixer will hang around. The low capacity of sodium fixer means I can mix it up from bulk chemicals (it's easy to do, the stuff dissolves readily), use it a couple of times, and either toss or reserve for work I'm not going to keep. Dan Quinn's single-shot fixing method takes the procedure even further. The amount of sodium thiosulfate necessary to fix the quantity of film is used and discarded. No concerns about iodides building up in the fixer, no oxidation or sulfurization worries, no sulfur dioxide coming out of it to bite your nose, no storage, no recording of age and usage. The preparation of a simple sodium thiosulfate fixer is so quick and easy that it rivals pouring out a shot of ammonium thiosulfate concentrate and diluting it -- while holding your breath! I just use Ansel Adams' plain fixer, which he describes in the appendix of one of his books (either The Neg or The Print, I forget right now). Very easy to do, very cheap, very quick. Very low capacity, so I'm never over-working it. It never gets old. It's so cheap I never bother moving my second fixer (I use a double bath system for fixing) to the first fixer position when I make a new bath. I just make two fresh baths. The issue of iodide buildup is easily dealt with. Permit no buildup. Use a sodium thiosulfate fixer to only half or two thirds of its rated capacity, so it never over-works. Or use it one shot. To claim that sodium thiosulfate fixers are not suitable because of iodides presupposes that workers will work them to the max and beyond. They fix perfectly well as long as they are not overworked. Ammonium fixers beg to be overworked because they claim such a high capacity, and because they cost a lot more than sodium thiosulfate and sodium sulfite in bulk. I develop ten rolls of 120 film per batch because one liter of Xtol diluted 1+2 covers them conveniently in my tanks. I use the Jobo 1500 series plastic spirals, which open to 120 width and easily load two rolls, one after the other (not back to back as in stainless reels). So my three liters cover five spirals conveniently. A five liter pack of Xtol therefore develops fifty rolls of film (about two hundred and fifty dollars CDN worth of film in my neck of the woods). I make up six liters of Adams' plain fixer, for two three-liter fixing baths. The supposed capacity of that fixer would be about seventy five rolls per three liters. I limit it to fifty rolls for the six liters in two baths. So when it's time to start again I make up a new batch of Xtol and a pair of three liter fixers. The fixer is a lot easier to prepare than Xtol (which is not exactly a challenge to dissolve...). I realize the difficulty of dealing with ammonium fixers is not so great, and it's not so very expensive, but its downsides are sufficiently bad in my opinion that I'm delighted to take the easier, cheaper, cleaner, odorless route of sodium thiosulfate fixers. If you'll forgive the polemic, I'd like to expound on the smell of ammonium thiosulfate fixers. That smell is the gas sulfur dioxide. It is released by rapid fixer and is the reason some darkrom workers believe a darkroom contains "fumes". My darkroom contains no fumes or airborne chemicals of any kind. The air quality in a darkroom need not be any worse than in one's bedroom, and very likely it can be a good deal better than in the kitchen. But to get back to sulfur dioxide -- sorry, I was influenced by my grade twelve chemistry teacher, the sarcastic hater of teenagers -- which is a gas that is readily soluble in water. When sulfur dioxide dissolves in water, sulfurous acid results. Since we're smelling the stuff, where would this water be located? In our mucous membranes. That's our lungs, all right? (Insert sneer at teenage classrrom.) Sulfurous acid oxidizes readily if it gets oxygen, which it does, since it's in our lungs. Oxidized sulfurous acid is sulfuric acid -- in the lungs. No wonder it smells bad. I regard ammonium thiosulfate as a specialized material for specialized work. For ordinary day to day darkroom work, I find sodium thiosulfate perfectly functional and completely lacking in detrimental factors. long-winded, eh?? --le Signature________________________________ Lloyd Erlick Portraits, Toronto. voice: 416-686-0326 email: portrait@heylloyd.com net: www.heylloyd.com ________________________________ > Ooops. I think I failed the mid-term.... Heck, I just figured you were guilty of posting before drinking your developer. ;) > (Revised) Conclusion: > > My morning coffee should work about right. Yep. Mine would require a little fortification, but it's still easier and more consistent to use crystals -- and probably cheaper, too, since I pa |
Enable EMail Alerts
Start New Thread
Reply to this Message