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Photo Forum / General Photo Topics / UK Photography / February 2004How many pixels is enough?
I've got an ink-jet printer that is claimed to be able to lay ink down at 2880 dpi. (I'm not sure if that's both horizontal and vertical, but let's assume it is). If I want to make an A3 print - say 10 in. by 16 in, at the printer's rated performance, and I don't want either the application software, nor the printer ROM to synthesise pixels, then I need to feed the printer with about 1266 Mp (mega being 1024 x 1024). But hang on, even the most expensive cameras I can find have a maximum CCD size of about 8 Mp - about 0.67% of what I need. So how do I do it? Obviously I don't print at 2880 dpi - but what print density do I use for quality that is comparable to conventional dye development in multi-layer film? (whose density relates to the size of the dye molecules I assume). And when does anybody ever print at 2880 dpi? And what use is such a printer? And finally how many pixels do I really need to make a good 8 in by 10 in or 10 in by 16 in print? Hence what sort of camera should I be buyiing? Advice gratefully received, unless it concludes with the word 'off'. Tony H I have always understoon that 200dpi on the print is sufficient. This doesn't stop more dpi looking better-just not much. 35mm film at 100lines/mm approaches this at 20x16. 200dpi for 2megapixels allows a print about 5" high. More is probably OK. > I've got an ink-jet printer that is claimed to be able to lay ink down at > 2880 dpi. (I'm not sure if that's both horizontal and vertical, but let's [quoted text clipped - 17 lines] > > Tony H >I have always understoon that 200dpi on the print is sufficient. Sufficient for what? Sufficient for you, maybe. I would advise 300 dpi, which makes a huge difference from 200 dpi. 400 dpi is even better, but the difference from 300 dpi is not as noticeable as 300 from 200. Gladly (gladly528@ntlworld.com) wrote... > I've got an ink-jet printer that is claimed to be able to lay ink down at > 2880 dpi. (I'm not sure if that's both horizontal and vertical, but let's > assume it is). If I want to make an A3 print - say 10 in. by 16 in, at the > printer's rated performance, and I don't want either the application > software, nor the printer ROM to synthesise pixels, then I need to feed the > printer with about 1266 Mp (mega being 1024 x 1024). Certainly not! > But hang on, even the most expensive cameras I can find have a maximum CCD > size of about 8 Mp - about 0.67% of what I need. So how do I do it? The printer dpi and camera dpi are not really the same thing. > Obviously I don't print at 2880 dpi - but what print density do I use for > quality that is comparable to conventional dye development in multi-layer > film? (whose density relates to the size of the dye molecules I assume). And > when does anybody ever print at 2880 dpi? And what use is such a printer? Imagine one pixel of your camera image. It will have a certain colour. Now, your printer will only have four to six different coloured inks with which to produce that colour. Thus, to reproduce a single camera pixel of a certain colour, the printer will need to lay down multiple dots. This is why you need a printer with (say) 2880dpi in order to reproduce a digital image with (say) 300 pixels per inch. > And finally how many pixels do I really need to make a good 8 in by 10 in or > 10 in by 16 in print? Hence what sort of camera should I be buyiing? As a general rule of thumb, somewhere in the order of 300 pixels per inch is seen as optimum for printing on an inkjet printer. Some with 2880dpi printers have found that 288 pixels per inch works very well for them. In many instances (especially enlargements that will only be viewed at a distance) resolutions down to around 150dpi can produce reasonable prints - although a lot depends on how "good" those pixels are in the first place. A cheap'n'nasty 3 megapixel digicam is not going to produce a better image (IMHO) than a 2 MP device with a much better lens. So, for 16x10" print @ 300dpi = 16 * 300 * 10 * 300 / (1024 * 1024) = 13.4 MP! 16x10 @ 300dpi = 13.4MP 16x10 @ 150dpi = 3.4MP 10x8 @ 300dpi = 6.9MP 10x8 @ 150dpi = 1.7MP > Advice gratefully received, unless it concludes with the word 'off'. From the above, if you want to regularly print premium quality 10x8's, you should perhaps be looking at a 6MP type camera. Hope some of this helps!  SignatureIan Riches Bedford, UK >I've got an ink-jet printer that is claimed to be able to lay ink down at >2880 dpi. (I'm not sure if that's both horizontal and vertical, but let's [quoted text clipped - 13 lines] >And finally how many pixels do I really need to make a good 8 in by 10 in or >10 in by 16 in print? Hence what sort of camera should I be buyiing? Convention says that a good quality print requires 300 pixels per inch, though for larger prints (which will be viewed from a greater distance) 240, 200 or even less may be adequate. The Printers dpi setting is something different, and relates to the fact that to get the colour of each pixel right the printer has to lay down a combination of dots of colour from it's ink set that produces the right mix of shades. Hence each pixel will be made up of several dots of the printers coloured inks. For your final question, in theory a "good" 8 x 10 at 300 ppi would be 2400 x 3000 pixels, but you can probably get away with less, and 6MP cameras can yield quite satisfactory 10 x 16 prints in practice. > I've got an ink-jet printer that is claimed to be able to lay ink down at > 2880 dpi. (I'm not sure if that's both horizontal and vertical, but let's > assume it is). If I want to make an A3 print - say 10 in. by 16 in, at the > printer's rated performance, and I don't want either the application > software, nor the printer ROM to synthesise pixels, then I need to feed the > printer with about 1266 Mp (mega being 1024 x 1024). You're making the classic mistake of confusing "dots per inch" with "pixels per inch". They're not the same. The dpi figure given for the printer indicates the number of ink droplets that the print head can spit at the paper. It is nothing to do with the number of pixels in any picture, but as it is usually a larger number, it is almost invariably the one that printer manufacturers quote. You can hardly blame them, because they are in business to sell printers, not to educate the public. In fact, a picture can be printed on paper at quite a low pixel resolution, as low as 150 pixels/inch perhaps, before the lack of resolution becomes annoying, and even lower if the pictorial content is of more importance than absolute photographic perfection. It is sometimes suggested that you should choose a pixel/inch figure that is a simple fraction of the dots/inch value for the printer, to avoid Moire type fixed patterning, but I've never seen this effect. In any case, it is exactly contrary to the wisdom applied in choosing subcarrier frequencies in colour television systems, where a deliberately *complicated* mathematical relationship is chosen between subcarrier and the line and frame structure of the picture, because fixed patterning occurs if you don't. Rod. > I've got an ink-jet printer that is claimed to be able to lay ink down at > 2880 dpi. (I'm not sure if that's both horizontal and vertical, but let's [quoted text clipped - 17 lines] > > Tony H Thanks for the responses so far. Summing up those responses, it seems clear that the camera manufacturer's claims of 5 Mp cameras being able to produce good quality A3 prints should be viewed like any other marketing claim: bullshit until proven (and often then proven to be bullshit). I also note the comment about the quality of the optics (which I suppose is self evident) being of equal importance to the size of the CCD. So, then, which manufacturer(s) of 5 Mp (6 Mp being out of my financial reach) cameras should I look at ? Nikon?, Sony? Canon? Olympus? Pentax? any others? Gladly (gladly528@ntlworld.com) wrote... > Thanks for the responses so far. Summing up those responses, it seems clear > that the camera manufacturer's claims of 5 Mp cameras being able to produce > good quality A3 prints should be viewed like any other marketing claim: > bullshit until proven (and often then proven to be bullshit). Yes and no. My father has produced A3 prints from his 3.9 MP Canon S40 that are quite passable *at a reasonable viewing distance*. If you look up close, then, of course, the sharpness is just not there. But to be honest, 35mm film when enlarged to A3 size can be pushing it unless you have ideal conditions (quality lens, film, tripod etc.) If you can get A3 prints that you are happy with from a "consumer" 35mm camera/lens, then you should be able to get A3 prints from a quality 5MP+ digicam that you are happy with, IMHO. Others may disagree! > I also note the comment about the quality of the optics (which I suppose is > self evident) being of equal importance to the size of the CCD. Indeed. > So, then, which manufacturer(s) of 5 Mp (6 Mp being out of my financial > reach) cameras should I look at ? Nikon?, Sony? Canon? Olympus? Pentax? any > others? All of those make some reasonable cameras. Decide what mix of features you want and then look at a website such as www.dpreview.com Things to consider from the spec sheet are (in no particular order): 1) Megapixels 2) Optical zoom (ignore digital zoom!) 3) Storage format (compact flash? SD? If you have devices such as PDAs that use one format already, you may wish to standardise!) 4) Manual override features 5) ISO speed range 6) Burst rate (how many frames, how quickly?) 7) Macro capability 8) Battery type and life e.g., if you want to capture sports, then you may want a camera with a long-ish lens, high ISO capability (to allow action-freezing high shutter speeds) and a fast burst rate. The actual number of pixels will perhaps be secondary. It's no good capturing millions of pixels of the wrong, blurred, moment! The www.dpreview.com site should give you a good idea of what models to be looking at in each price bracket. Ian SignatureIan Riches Bedford, UK > Thanks for the responses so far. Summing up those responses, it seems clear > that the camera manufacturer's claims of 5 Mp cameras being able to produce > good quality A3 prints should be viewed like any other marketing claim: > bullshit until proven (and often then proven to be bullshit). I've produced very acceptable A3 prints from a 3 Mp camera. It depends on the subject matter, the intended viewing distance, and whether people will be expected to look at it with their eyes, or a magnifying glass. A television picture is about 0.4 Mp. A "high definition" television picture (1080 active lines) is about 2 Mp. Rod. > > Thanks for the responses so far..... > [quoted text clipped - 7 lines] > > Rod. That's a very interesting statistic - kind of puts things into perspective. I haven't seen HDTV as yet, but I tend to watch my old 22" screen fairly closely (being of that age) and am singularly unimpressed by the image quality cf that from the same manufacturer of the 21" CRT on my PC. What has impressed me is how 35 mm slides which I took about 50 years ago, (now reaching the end of their life) with a borrowed Nikon SLR (FTN ?) can be viewed at a size of about 2000 mms (on the diagonal, and which is larger than A0), when projected onto a 35 year old screen from a similar age projector (both Prinz, which I think was the origin of Dixons). These slides have superb detailing when viewed from about 3 m distance, and also look quite good when standing close to the screen. Of course I'm not sure how this compares to going from a 1-1/8" CCD to an A3 print, to be viewed at arm's length. Most of my subject material is architectural or landscape in nature. (I do not have the talent to photograph live subjects in such a way as to capture the essence of their vitality and spend so much time composing the shot that events in motion have long since passed me by before I'm ready). So I guess I need to focus on good definition, wide angle, low noise, good colour balance and the ability to set my own exposure times, when reading DPReview. I shall be mighty pleased if I can find an affordable 5 Mp digicam which matches the optical quality, usability and reliability of my old SLRs. I'm scanning those old negs and transparencies with a Nikon Coolscan 4000 ED. I want the prints to do justice to the scans as well as the original material. > > A television picture is about 0.4 Mp. > > [quoted text clipped - 6 lines] > closely (being of that age) and am singularly unimpressed by the image > quality cf that from the same manufacturer of the 21" CRT on my PC. Television pictures probably look better than they should because they are moving. Picture information is moving against the fixed pattern of sampling points, giving the impression of more sampling points than there really are, because over a period of time every point on of the image will be sampled, not just those image points that coincide with the sampling points. The difference is made obvious when you take a still frame from a television signal, and find that something that was quite watchable as a moving picture is absolutely atrocious as a still. This will happen even if you are lucky enough to be able to tke a full frame with all the lines because the image wasn't moving very fast, but more usually you will have to take just a single field, which will only give half the number of lines and therefore half the vertical resolution. There is a popular technique in television that effectively amounts to throwing away every other line and replacing it with information from the remaining ones. It's done (I think) to make moving objects move jerkily at 25Hz instead of 50Hz to resemble the way things move on cine film, but of course a side effect is that the vertical resolution is halved, so you end up with a picture made from only 288 lines. If it's a widescreen broadcast, the analogue viewers will see a version where the height has been reduced by 1/7th (to make the compromise 14:9 shape), so you end up with a picture made from 702 x 247 pixels. Not very impressive when expressed in numbers, but many millions of people spend hours watching pictures like these and apparently enjoy them. Rod. > If it's a widescreen broadcast, the >analogue viewers will see a version where the height has been reduced by >1/7th (to make the compromise 14:9 shape), so you end up with a picture made >from 702 x 247 pixels. Not very impressive when expressed in numbers, but >many millions of people spend hours watching pictures like these and >apparently enjoy them. It's much the same as people buying 6 megapixel digital cameras and marvelling at the quality displayed on 1024 x 768 pixel PC monitors. For viewing on a PC monitor (even a 17 inch screen set at 1280 x 1024 pixels), a 2 megapixel camera is overkill. >I shall be mighty pleased if I can find an affordable 5 Mp digicam which >matches the optical quality, usability and reliability of my old SLRs. You won't. Even the 16 Mp and 22Mp digital backs for medium format cameras cannot equal the resolving power of 35mm Fuji Provia 100F. > I'm scanning those old negs and transparencies with a Nikon Coolscan 4000 ED. I >want the prints to do justice to the scans as well as the original material. A 35mm slide scanned at 4000 ppi gives 24 million multi-coloured pixels. The latest 16 Mp and 22Mp digital backs for medium format cameras give only single colour pixels, therefore providing less than either one third or one quarter of the information from a scanned 35mm slide. Film will reign supreme for a few years yet. > A 35mm slide scanned at 4000 ppi gives 24 million multi-coloured > pixels. The latest 16 Mp and 22Mp digital backs for medium format > cameras give only single colour pixels, therefore providing less than > either one third or one quarter of the information from a scanned 35mm > slide. Picture quality is not all about pixels and resolution, any more than hi-fi is all about needing a 500W amplifier for your living room. If you have as much as you need, then you don't need ten times more. > Film will reign supreme for a few years yet. Depends what you mean by "supreme". Electronic photography is becoming more popular by the day, because of its convenience, regardless of "quality". You may nitpick about the niceties of what you regard as the most important aspects of photographic quality, but for many people it's already good enough for their needs, and will only improve as the years go by. I wouldn't be surprised if within ten years, or perhaps a s few as five, it becomes very difficult to buy film in the high street. Film for still photography will become a niche market, just as it has for home movies. Rod. >Picture quality is not all about pixels and resolution, any more than >hi-fi is all about needing a 500W amplifier for your living room. If you >have as much as you need, then you don't need ten times more. In other words, for those who aspire to no more than mediocre image quality, digital is already good enough. I can't disagree with that! ;-) > >Picture quality is not all about pixels and resolution, any more than > >hi-fi is all about needing a 500W amplifier for your living room. If you [quoted text clipped - 4 lines] > > I can't disagree with that! Depends on how you define "mediocre". How would you compare a technically imperfect but interesting picture with one that never got taken at all because the technically superior camera kit was so cumbersome you left it at home? Photography is about pictures, not cameras. In any case, all aspects of digital photography (and image quality is only one of these) are enticing many people to buy the equipment. If that's where the profits are, then it's only a matter of time before the manufacturers have improved the quality to a level that even the film fetishists will find satisfactory. Think carefully before sticking your neck out and saying it will never happen. Rod. >Depends on how you define "mediocre". How would you compare a technically >imperfect but interesting picture with one that never got taken at all >because the technically superior camera kit was so cumbersome you left it at >home? For several years now, I have never missed a shot because I didn't have a high quality camera with me. I always carry a 35mm compact camera. Until recently I used an Olympus Mju II, now I carry a Contax T3. Years ago I carried a Yashica Electro 35 GSN. So your question is irrelevant. >>I shall be mighty pleased if I can find an affordable 5 Mp digicam which >>matches the optical quality, usability and reliability of my old SLRs. [quoted text clipped - 12 lines] > >Film will reign supreme for a few years yet. Doesn't mean a damn if the wrong glass is attached to the camera. High resolution is fine if you have a need for it. Many will take great pleasure from low to medium resolution images. It should also be pointed out that greater resolution doesn't infer that you will suddenly be able to take better photographs ;-) SignaturePete Lawrence http://www.pbl33.co.uk Home of the Lunar Parallax Demonstration Project > Doesn't mean a damn if the wrong glass is attached to the camera. Depends somewhat on your film as well - with ISO400 B&Ws I find that above around 3000dpi I'm just resolving the grain more clearly! SignatureCan't you see / It all makes perfect sense When expressed in dollars and cents / Pounds, shillings and pence -Roger Waters, from the album "Amused to Death" --------------------------------------------------------------- Simon Waldman, UK email: swaldman@firecloud.org.uk http://www.firecloud.org.uk/simon --------------------------------------------------------------- >Doesn't mean a damn if the wrong glass is attached to the camera. You must be the latest recipient of an honours degree in stating the bleeding obvious. >>Doesn't mean a damn if the wrong glass is attached to the camera. > >You must be the latest recipient of an honours degree in stating the >bleeding obvious. Sometimes it needs to be restated many times, very loudly. BTW, you also need a tripod if this argument is to have relevance........... I have an archive of about 7,000 35mm slides, mostly on Kodachrome 25, and there are perhaps half a dozen shots where film/lens resolution is the limiting factor on technical quality. SignatureStewart Pinkerton | Music is Art - Audio is Engineering >I have an archive of about 7,000 35mm slides, mostly on Kodachrome 25, >and there are perhaps half a dozen shots where film/lens resolution is >the limiting factor on technical quality. Sounds like you still have a lot to learn. Maybe the first thing to learn is that your slide collection is too large - it is almost always a sign of an undiscerning photographer. >>I have an archive of about 7,000 35mm slides, mostly on Kodachrome 25, >>and there are perhaps half a dozen shots where film/lens resolution is >>the limiting factor on technical quality. > >Sounds like you still have a lot to learn. Well of course - art is like that. >Maybe the first thing to learn is that your slide collection is too >large - it is almost always a sign of an undiscerning photographer. Maybe the first thing to learn is that it's an archive which spans more than 40 years of serious photography, making less than 200 shots a year, many of which are records rather than 'pure art'. If you can't take that many decent shots per year, then perhaps it's you who has a lot to learn....................... BTW, since I've been in the portfolio of the Scottish Photographic Federation, the Salon at the Edinburgh Festival, and the Hong Kong International Exhibition, perhaps my record of discernment isn't all that bad. SignatureStewart Pinkerton | Music is Art - Audio is Engineering >>I have an archive of about 7,000 35mm slides, mostly on Kodachrome 25, >>and there are perhaps half a dozen shots where film/lens resolution is [quoted text clipped - 4 lines] >Maybe the first thing to learn is that your slide collection is too >large - it is almost always a sign of an undiscerning photographer. Wow that one takes the arrogance award for February. You know nothing of Stewarts collection. I've taken in excess of 10,000 digital images since 2000 - I guess I'm *really* undiscerning then. SignaturePete Lawrence http://www.pbl33.co.uk Home of the Lunar Parallax Demonstration Project >I've taken in excess of 10,000 digital images >since 2000 - I guess I'm *really* undiscerning then. Certainly sounds like it! ;-) >>I've taken in excess of 10,000 digital images >>since 2000 - I guess I'm *really* undiscerning then. > >Certainly sounds like it! > >;-) A good demonstration of how easy it is to make an unqualified and somewhat foolish assessment. I do a lot of astrophotography. A useful digital imaging technique is that which incorporates image stacking to improve the signal to noise ratio in an image. This often requires the imager to take a multitude of shots of the same subject for later combination. The result of the image stacking process is a far cleaner image than taking a single shot. I tend to keep all of the component images in an archive in case better techniques/software comes forward to allow me to eek even more detail out. Thanks for helping make the point ;-) SignaturePete Lawrence http://www.pbl33.co.uk Home of the Lunar Parallax Demonstration Project > >I have an archive of about 7,000 35mm slides, mostly on Kodachrome 25, > >and there are perhaps half a dozen shots where film/lens resolution is [quoted text clipped - 4 lines] > Maybe the first thing to learn is that your slide collection is too > large - it is almost always a sign of an undiscerning photographer. I feel I must make a comment here, at the risk of being severely reprimanded for doing so: I posed the question of how many pixels are enough etc a few days ago. It has created a lot of very helpful (to me at least) discussion. But I am saddened to see that it has also sparked some personal 'assessments' that seem to be both slightly off the original topic, and, more importantly, less than totally civilised. We're living in an age where politicians and their paid advisors are creating reprehensible role models of public probity. Let's not emulate them here, please. Gladly the X-eyed Bear "Whatever you may be sure of, be sure of this, that you are dreadfully like other people" > [...] > I posed the question of how many pixels are enough etc a few days ago. It [quoted text clipped - 3 lines] > than totally civilised. > [...] Be thankful that the only arrogant blowhard regularly posting here is "TP"; try "rec.photo.digital" for a day or two. Aside from the out-and-out trolls and spammers (who seem to be attracted to rpd more than to any other usenet group I've seen), and the inability of regular posters to refrain from replying to them, the newsgroup is full of ludicrous TP clones, each assured of his own infallibility and with an opinion on everything (as well as sharing TP's somewhat shaky grasp of the English language). "uk.rec.photo.misc" is a delight by comparison. Peter J. King > I posed the question of how many pixels are enough etc a few days ago. It > has created a lot of very helpful (to me at least) discussion. But I am > saddened to see that it has also sparked some personal 'assessments' that > seem to be both slightly off the original topic, and, more importantly, less > than totally civilised. Your sensitivity is commendable Gadfly, though I fear that Usenet is bound to disappoint you. "Civility" and "unmoderated Usenet groups" are not things that go together. The quality of opinions on offer varies from the profoundly wise to the totally ignorant, but however well-informed they are, the participants' views are strongly held and debates are invariably robust. It occurs to me that much of the current film vs. digital debate on the Usenet photo groups is just the latest iteration of the Leica vs. Contax, Hasselblad v Rollei, Nikon v Canon, Kodak v Fuji type rows that have raged in photographic circles for almost as long as photography has been around. Among some photo enthusiasts there seems to be a need to validate their personal choice of equipment or technique by insisting that the products from a competing manufacturer are rubbish. Freud would probably locate this behaviour in a genitally-based sexual insecurity. Whatever the case, it quickly becomes tiresome for those of feel that differences in equipment, media, techniques and so on add to the richness of photography rather than take away from it. Stewart Gardiner >Among some photo enthusiasts there seems to be a need to validate their >personal choice of equipment or technique by insisting that the products [quoted text clipped - 3 lines] >media, techniques and so on add to the richness of photography rather than >take away from it. It happens amongst numerous other groups as well - photography isn't alone. It's sometimes rather amusing to watch arguments about my gear/methodology is better than your gear/methodology and reflect as to the lack of tangible results that have appeared from either party (coming from a fishing town we describe it as "all tackle and no rod"). This is not quite the case here and I'm sure that those that argue the worth of film over digital have superb results under their belt. However, you don't have to have 'the' gear to take the best photographs. Photography is not a cold technical subject, it's also an artform. If a low resolution image can instill emotion in those that view it, then it's done it's job in my book. SignaturePete Lawrence http://www.pbl33.co.uk Home of the Lunar Parallax Demonstration Project > > > (snip). > [quoted text clipped - 14 lines] > > Stewart Gardiner Aha, now I understand where all these feelings of sexual deprivation come from. It's nothing at all to do with my age or single status; no, it all results from the fact that you didn't mention Pentax! I can see I'm going to have to change my plans. I was thinking of an Optio 555 to complement my Super-A, but perhaps I should be looking at something potent enough to stir up a lot of hot feelings...... >>Doesn't mean a damn if the wrong glass is attached to the camera. > >You must be the latest recipient of an honours degree in stating the >bleeding obvious. And you are the latest with a physical award in shouldering the film is better than digital chip. Actually, my honours degree is in Physics with Astrophysics which may not be bleeding obvious ;-) SignaturePete Lawrence http://www.pbl33.co.uk Home of the Lunar Parallax Demonstration Project >>You must be the latest recipient of an honours degree in stating the >>bleeding obvious. > >And you are the latest with a physical award in shouldering the film >is better than digital chip. I make my living from photography, and I use both film and digital gear. When I need results of the highest quality I know which to use. When I need the speed and convenience of the other, then I use it. I don't need you, or anyone else, to tell me which gives the best image quality. The difference is huge, no matter how loud the apologists for digital may shout. When digital overtakes film I expect I will no longer shoot film, but I am still investing in new film gear and expect to continue to do so for some years yet. >>>You must be the latest recipient of an honours degree in stating the >>>bleeding obvious. [quoted text clipped - 5 lines] >gear. When I need results of the highest quality I know which to use. >When I need the speed and convenience of the other, then I use it. Good for you. So you need the quality. Not everyone that does photography does though. Some do photography because it gives them and others pleasure. This isn't uk.pro.photo.misc. >I don't need you, or anyone else, to tell me which gives the best >image quality. The difference is huge, no matter how loud the >apologists for digital may shout. Touchy aren't we? When did I tell you which gives you the best image quality? >When digital overtakes film I expect I will no longer shoot film, but >I am still investing in new film gear and expect to continue to do so >for some years yet. Broaden your view - digital has overtaken film in some subjects. SignaturePete Lawrence http://www.pbl33.co.uk Come and visit the "Lunar Parallax Demonstration Project" >Good for you. So you need the quality. Not all the time, no. Try reading what I wrote before replying. >>Good for you. So you need the quality. > >Not all the time, no. Try reading what I wrote before replying. Did I say all the time? SignaturePete Lawrence http://www.pbl33.co.uk Come and visit the "Lunar Parallax Demonstration Project" > >>Doesn't mean a damn if the wrong glass is attached to the camera. > > [quoted text clipped - 6 lines] > Actually, my honours degree is in Physics with Astrophysics which may > not be bleeding obvious ;-) I think Tony is more deserving of the Rip Van Winkle Award, or perhaps the Blind Photographer Award. The Canon 1Ds has been out for more than a year, and it produces dramatically better image quality than drum-scanned Provia 100 F. Brian www.caldwellphotographic.com >> >>Doesn't mean a damn if the wrong glass is attached to the camera. >> > [quoted text clipped - 11 lines] >than a year, and it produces dramatically better image quality than >drum-scanned Provia 100 F. But not approaching that of optically enlarged Provia 100 F, and a mile away from Kodachrome 25. The only hope for digital at that kind of lens-challenging resolution in the near future is your kind of stitched mosaics, which are hardly representative of 'the decisive moment', and could have been done just as well (or better) with a 5x4 monorail. I do use a digital camera (Sony DSC-85) for holiday snaps and as an every day carry, but not for 'serious' photography. No doubt that will change when Nikon bring out a decent body with say 20 Mpixels on a 24x36 sensor, but not yet. I'm not chopping in all my Nikkors for Canons just to get the 1Ds body - I ain't that rich! SignatureStewart Pinkerton | Music is Art - Audio is Engineering >But not approaching that of optically enlarged Provia 100 F, and a >mile away from Kodachrome 25. It doesn't approach the quality of drum scanned Provia100F either. Brian is simply flying a kite whose aerodynamics are but a figment of his imagination. He'd love it to be true, so he makes the statement that it is. It isn't. >I think Tony is more deserving of the Rip Van Winkle Award, or perhaps >the Blind Photographer Award. The Canon 1Ds has been out for more >than a year, and it produces dramatically better image quality than >drum-scanned Provia 100 F. I have extensively used a 1Ds and regularly scan Provia 100F with a variety of scanners. I can categorically refute Brian's statement; it is nonsense, pure and simple. But like almost everything Brian says, it is what he wants to believe, rather than anthing that is supported by the facts. A third rate low-grade security camera lens designer who aspires to a knowledge of photography that he simply doesn't have, he is a constant source of amusement thanks to his propensity for making unsupportable "statements" about subjects he knows virtually nothing about. Proof, if ever needed, that a little knowledge is a dangerous thing. > Proof, if ever needed, that a little knowledge is a dangerous thing. A statement that is effectively proof of itself, because the actual quotation is "A little learning is a dangerous thing". Rod. > >I think Tony is more deserving of the Rip Van Winkle Award, or perhaps > >the Blind Photographer Award. The Canon 1Ds has been out for more [quoted text clipped - 13 lines] > > Proof, if ever needed, that a little knowledge is a dangerous thing. As you are uncomfortably aware, I usually have plenty of support for my "unsupportable" statements. For example, here is a revealing comparison of the 1Ds with Provia 100F scanned two different ways (drum and 4000dpi CCD): http://www.outbackphoto.com/reviews/equipment/Canon_1DS/Canon_1Ds_Diary_part1.html Other visual comparisons are similarly dramatic. If you want, I can find the links for you. Visual evidence is very hard to refute. It amazes me that you so often attempt to do so. If you can actually show that scanned 100F produces superior image quality to the 1Ds then show it, don't just say it. If you have nothing to show, then at least try to explain why every head-to-head comparison indicates that you're wrong. Brian www.caldwellphotographic.com (snip) > Thanks for the responses so far. Summing up those responses, it seems clear > that the camera manufacturer's claims of 5 Mp cameras being able to produce [quoted text clipped - 7 lines] > reach) cameras should I look at ? Nikon?, Sony? Canon? Olympus? Pentax? any > others? --------- As others have pointed out that pixels (ppi) and printer dots (dpi) are two different things completely - I'll try and give you actually a different way to think about that... The classic question around the web today is "How big is a pixel?" and the appropriate answer is "How big do you want it?" Now imagine a single pixel that is 4 inches by 4 inches (and yes it can exist - a single pixel can be ANY size) then put it to your printer at 1440 dpi - what do you get? An image of that single pixel that would be nominally square, but may NOT actually print at 4 inches on the side, and it will also be printed with the printer depositing 1440 dots of ink per inch across the entire width and height of that single pixel image. The advantage of higher dpi printing is usually one of uniformity of colour and continuous tone or shifting tone and values over, say, the results you would get at lower dpi settings. Many printers also will produce banding and other printer artefacts at lower dpi settings that disappear when more link is laid down at the higher dpi settings. The disadvantage to selecting high dpi values is in the speed with which the printer will handle and print the image. Faster at lower dpi settings and slower at the higher settings. ------- As for image resolution...not to confuse you BUT every printer also has what is called a "line screen value" - in fact more than one. Typically, for a printer at home and running paper that is a coated "photo" grade / type (and you tell the printer that is what you are using - as opposed to plain paper or uncoated card - what ever choices the printer may allow) the screen value would be expected to be about 150 (lines per inch). Image resolutions are typically set from 1.5 to 2 times the print screen value - therefore, for a photographic image on photo paper to reach the normal output print quality associated with that lpi value, it should be between 225 PPI (pixels per inch) and 300 PPI based on the notional image size in inches. Thus, the usual recommendation that images should be prepared for printing at 300 PIXELS per inch. An image set to print at 8 x 10 inches, then, at 300ppi, would be an image described as one having 2400 pixels in one dimension and 3000 in the other - aka 2400 x 3000 pixels. Depending on the actual printer and the options available - a lower line screen value may be set internally. You can NOT control this value - but by selecting higher or lower paper grades you can fool the printer into using one or another available line screen values. The lpi value for lower grades of paper such as "plain paper" is typically 100 lpi, more or less, and even as low as 50 to 75 lpi for "draft" print modes on the same plain paper. All this really affects in printing, say, a text document, is the sharpness of the letters and the amount of ink laid down on the paper surface - but it would not produce a high quality photographic image print output. Journalist > (snip) > > [quoted text clipped - 53 lines] > > Journalist This discussion is getting to the heart of the things that concern me about moving to digital photography. I think I must make this transition in order to preserve the legacy of all those photos I have taken over the years (99.9% of which will be of zero interest to whoever gets them when I'm gone, but, while it's very easy on a few nano-seconds glance to pick the ones which are in that 99.9%, unfortunately I don't know which ones fall into the 0.1%). I'd like to discuss this matter (of how print density and image resolution interact) further, but it's probably desperately yawn-making for the rest of the better informed (better than me that is) readers of this ng. Can you recommend suitable books/papers I should be looking at? Regards Gladly the X-eyed Bear > [...] > This discussion is getting to the heart of the things that concern me about [quoted text clipped - 4 lines] > which are in that 99.9%, unfortunately I don't know which ones fall into the > 0.1%). It's all the ones that you didn't pick as being in the 99.9%. PJK (snip) > I'd like to discuss this matter (of how print density and image resolution > interact) further, but it's probably desperately yawn-making for the rest of [quoted text clipped - 4 lines] > > Gladly the X-eyed Bear -------- Actually, no, I can't recommend any particular books but there is a --- L O T --- of the information available on the web. Too much, in reality, and often not completely stated in one place or the other. It's only a matter of where you look and what to look for. Typically you could search print or printer screens; also look at the term "dot gain"; as well as DTP - Desk Top Publishing - and sub-search "printing"; offset printing; web press printing; and tons more. Much of what a desktop printer does is not any different then a big commercial web or offset press. It operates the same in respect to dots per inch; ink deposition; print density; "dot gain" (how the ink spreads on particular papers); colour control; image resolutions; and line screening (though computer printer manufacturer's don't usually think that the LPI values are even worth mentioning as they can not be controlled by the user - they are nevertheless built into the design of machine itself.) Epson is one manufacturer that does mention the value for some of it's products, but only in passing. You should also keep in mind that even though most desktop printers ask for (and you give them) RGB images they actually print in CMYK or CMYK++ additional inks (and commercial presses will also use the basic 4, and, alternatively 5, 6, or...up to 8 colours as well including specials such as Pantone inks and metallic). The best information you will see on printing that can be translated to your own use on a desktop printer comes from the commercial printing and publishing industries. You will get a little info from here, and a little info from there, until you build up the whole picture in your own mind and are able, then, to experiment a bit with your own printer within it's own capabilities. ---- As to the "better informed"...the less said the better, but from the range of answers, and even the discussion about just what is and isn't a good print in this one message thread, you should realise that not everyone is really "informed" to begin with. Some may be more, or less, "informed", or "better informed", myself included. I am in the same position as many others, as I am a journalist and photographer and not a printer by trade. The only reason I am perhaps marginally better "informed" is because I do have to work with hands-on commercial print houses and graphic artists day to day; and I also do page layouts and composition for pre-press, including working with the HQ scans, RIPpers (RIP = Remote Image Protocol - the same as a printer driver in your own computer but applied to a commercial press), imagesetter and plate maker requirements, as well as production colour control...soooooo...sooner or later something about the demands the printers make, indeed have to make, to get the best out of the printing process was bound to sink in. Across this photo forum and many, many others, there are literally thousands of messages about printing "problems." As I see both the problem and the solution (but mainly the problem) the average photographer, amateur or pro, does not know, or necessarily want to learn, very much about "printing". A lot don't even know that they don't know --- UNTIL --- they run into a brick wall (or one falls on them) on colour matching or print quality problems. Some day someone will produce a handbook for the purpose that brings together, comprehensively, the data on image printing; print, printer and colour calibration; profiling and other matters that apply to desktop printing...but until then...it's every man (and woman) for himself. LOL Journalist >I've got an ink-jet printer that is claimed to be able to lay ink down at >2880 dpi. (I'm not sure if that's both horizontal and vertical, but let's >assume it is). It will be 2880 x 720 dpi. The 2880 is the transverse resolution, which is determined by the precision of the ink spray heads and their carriage. The 720 dpi is the longitudinal resolution, which is determined by the precision of rotation of the drum. 2880 dpi is very good for the former. 720 dpi is very good for the latter, but it does mean that your printer's effective resolution is 720 dpi and not 2880 dpi. Sorry to burst your bubble (jet). ;-) > > snip. > [quoted text clipped - 10 lines] > > ;-) Thanks for this. I'm not greatly surprised. In a previous incarnation I was often required to convince people that a pile of vastly over-priced Second Hand Information Technology was in fact leading edge IT. We called it marketing then. Today it's called politics. Happily though the consensus of opinion so far is that 720 dpi printer is probably good enough to make a good quality print This assumes that a 5 Mp digicam will have good enough optics and provide enough pixels which are sufficiently accurate representation of the original subject to make a good print. The only weakness then is the person who chooses and composes the scene. How do I overcome that one? >The only weakness then is the person who chooses and composes the >scene. > >How do I overcome that one? Learn, through: - tuition, - reading books on photography, or - trial and error. All take time. > >How do I overcome that one? > > Learn, through: > - tuition, > - reading books on photography, or > - trial and error. - Usenet ? ;^) Signature"I'm your Huckleberry !!" - Doc Holliday "Tombstone" >- Usenet ? Nah, that just teaches you how to be rude ... I've been on Usenet for over 10 years now! ;-) > >- Usenet ? > > Nah, that just teaches you how to be rude ... Bollocks! I learned shitloads on Usenet. Feck off. > I've been on Usenet for over 10 years now! Without a single toilet break... amazing... -- Here lies the late Martin Francis He couldn't tell you the technical merits of Leitz and Zeiss But he did take some photographs once. > >- Usenet ? > > Nah, that just teaches you how to be rude ... Good Grief, I must be doing it wrong then, except when JermBoy Jeremy is around on r.p.e.35mm SignatureA Lot Of Good Luck Is Undeserved, But Then So Is A Lot Of Bad Luck >>Learn, through: >>- tuition, >>- reading books on photography, or >>- trial and error. > > - Usenet ? <rummages in sigfile> Ah: "Go not to UseNet for counsel, for they will say both `No' and `Yes' and `Try another newsgroup'." Signature--------------------------------------------------------------- Simon Waldman, UK email: swaldman@firecloud.org.uk http://www.firecloud.org.uk/simon --------------------------------------------------------------- |
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