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Photo Forum / Digital Photography / DSLR Cameras / September 2006Confused about "Digital" Lens
On a few occasions, I've seen references to "digital" lenses. These are lenses that are optimized to have photons hit the digital sensor at a perpedicular angle. Allegedly, lenses optimized to work with digital sensors would produce better results for a digital camera than a lens designed originally with film in mind. It seemed to make sense to my feeble mind. So now I'm wodnering why I don't see Nikon or Canon lenses with these "digital lens" designations. Is it because these companies are making compromises for the sake of compatibility with film cameras? Or is it because this whole "digital lens" thing is just a load of crap? > On a few occasions, I've seen references to "digital" lenses. These > are lenses that are optimized to have photons hit the digital sensor at [quoted text clipped - 7 lines] > compromises for the sake of compatibility with film cameras? Or is it > because this whole "digital lens" thing is just a load of crap? Canon have their EF-S range that is digital only. Nikon I am not sure about. Pentax has their digital only range. They have a smaller image circle so can be made smaller and ligher and will vignet on a larger sensor camera. Nikon dgital lenses are designated with the "DX" indentifier. > > On a few occasions, I've seen references to "digital" lenses. These > > are lenses that are optimized to have photons hit the digital sensor at [quoted text clipped - 13 lines] > They have a smaller image circle so can be made smaller and ligher and will > vignet on a larger sensor camera. My Pentax 16-45mm digital lens only vignets from about 20mm down but probably also looses sharpness at the edges so I have not used it on my film cameras at all yet but may experiment a little (takes some time to see the results though). . > Nikon dgital lenses are designated with the "DX" indentifier. > [quoted text clipped - 17 lines] >> will >> vignet on a larger sensor camera. > My Pentax 16-45mm digital lens only vignets from about 20mm down but > probably also looses sharpness at the edges so I have not used it on my film > cameras at all yet but may experiment a little (takes some time to see the > results though). Your 16-45 might not stop down properly on a Pentax film body. This varies from body to body and in some cases from mode to mode, but it's true of all Pentax DA and FA-J lenses. But it doesn't have anything to do with being 'digital' or not... Just a compatibility design decision by Pentax. >> My Pentax 16-45mm digital lens only vignets from about 20mm down but >> probably also looses sharpness at the edges so I have not used it on my [quoted text clipped - 8 lines] > do with being 'digital' or not... Just a compatibility design decision > by Pentax. Quite correct. It will work fine on the newer AF cameras except for the edge softness and vignetting I think but it does not have an aperture ring so metering is a problem of course on those cameras that rely on the ring and they simply will not work if you cannot set the aperture externally. According to Pete D <no@email.com>: > > On a few occasions, I've seen references to "digital" lenses. These > > are lenses that are optimized to have photons hit the digital sensor at > > a perpedicular angle. Allegedly, lenses optimized to work with digital > > sensors would produce better results for a digital camera than a lens > > designed originally with film in mind. It seemed to make sense to my > > feeble mind. It does not seem to make much difference in reality. I'm using a bunch of lenses designed for film on my D70, and have observed no problems with them. I would expect the most possible problems of this sort on extremely wide angle lenses -- but the ones most likely to generate problems would be the ones which also need the mirror locked up to allow the lens to mount and function (thinks like the old 8mm Fisheye lens from Nikon stuck so far back that they would also impact the mirror if it were not locked up. > > So now I'm wodnering why I don't see Nikon or Canon lenses with these > > "digital lens" designations. Is it because these companies are making [quoted text clipped - 3 lines] > Canon have their EF-S range that is digital only. Nikon I am not sure about. > Pentax has their digital only range. So does Nikon -- in the "G" series lenses. The 18-70mm "kit" lens for the D70 and D200 is one example of this -- and it mounts far enough from the sensor so there is no mirror interference problem, and the actual angle of the light hitting the sensor is not nearly as wide as the lens' focal length would cause you to expect. A real 18mm lens would have to be mounted so far into the body that the mirror would be hit. However, the design of the 18-70mm is such that this is not a problem. One interesting feature of the new "G" series lenses is the lack of an aperture ring. The camera body is expected to command the lens to the proper aperture -- which makes this lens useless on a film body -- aside from the feature mentioned in the following paragraph, which applies to the Nikon lenses for digital as well. > They have a smaller image circle so can be made smaller and ligher and will > vignet on a larger sensor camera. And Nikon -- so far -- has standardized on a 1.5 crop factor for *all* of their DSLRs. Enjoy, DoN.  SignatureEmail: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- > ...I would expect the most possible problems of this > sort on extremely wide angle lenses -- but the ones most likely to > generate problems would be the ones which also need the mirror locked up > to allow the lens to mount and function (thinks like the old 8mm Fisheye > lens from Nikon stuck so far back that they would also impact the mirror > if it were not locked up. I thought about this, wanting to do a wide angle pinhole shot with foil and the mirror locked up but the MLU mode in a D200 returns everything to normal after the shot is taken so I guess that old lens won't work. In MLU mode, the first click raises the mirror, the second takes the shot & drops the mirror. SignaturePaul Furman http://www.edgehill.net/1 Bay Natives http://www.baynatives.com > According to Pete D <no@email.com>: >> [quoted text clipped - 47 lines] > Enjoy, > DoN. > According to Pete D <no@email.com>: >> [quoted text clipped - 37 lines] > aside from the feature mentioned in the following paragraph, which > applies to the Nikon lenses for digital as well. I am surprised that they will not work on newer film bodies, lenses with no aperture ring work on the newer AF cameras because you can set both aperture and shutter from the body. >> They have a smaller image circle so can be made smaller and ligher and >> will >> vignet on a larger sensor camera. > > And Nikon -- so far -- has standardized on a 1.5 crop factor > for *all* of their DSLRs. It seems to be a good compromise with performance versus cost allowing quite a range of performance, many people simply don't need to spend the extra. > Enjoy, > DoN. According to Pete D <no@email.com>: > > According to Pete D <no@email.com>: [ ... ] > >> Canon have their EF-S range that is digital only. Nikon I am not sure > >> about. [quoted text clipped - 16 lines] > > I am surprised that they will not work on newer film bodies, Mechanically -- they will. The N90s is an example of that. However -- the lens does not cover properly to the corners of full-frame film. (Granted, I have not been able to test this, because my N90s is built into a conversion to digital by Kodak -- the NC2000e/c made for the AP. It was my first digital SLR. And it, too, has a crop factor, though I don't remember precisely what it was. But it was only a 1.3MP sensor, so I don't do much with it now that I have the D70. I *could* shoot film in it -- if I had one of the film backs. :-) > lenses with no > aperture ring work on the newer AF cameras because you can set both aperture > and shutter from the body. Agreed -- but the 'G' series lenses also are not designed to cover anything larger than the 1.5 crop factor sensor of the digital Nikon DSLRs. > >> They have a smaller image circle so can be made smaller and ligher and > >> will [quoted text clipped - 5 lines] > It seems to be a good compromise with performance versus cost allowing quite > a range of performance, many people simply don't need to spend the extra. Agreed. And it makes for nice long coverage from existing lenses, and my personal shooting style prefers the longer reach for most things. Enjoy, DoN. SignatureEmail: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- >> >> Canon have their EF-S range that is digital only. Nikon I am not sure >> >> about. [quoted text clipped - 5 lines] >cover anything larger than the 1.5 crop factor sensor of the digital >Nikon DSLRs. Don, just a correction here - the G series moniker simply designates a lense that does not have an aperture ring. You will find there are several G lenses that are designed for full frame/film bodies. The DX moniker is used to designate a smaller image circle for digital sensors. According to Bill <bill@c.a>: > >> >> Canon have their EF-S range that is digital only. Nikon I am not sure > >> >> about. [quoted text clipped - 12 lines] > The DX moniker is used to designate a smaller image circle for digital > sensors. My mistake. Thanks for correcting me on this. The "kit" lens is the only 'G' series lens which I have. I did not realize that there were some made with coverage for full film frame size. Thanks, DoN. SignatureEmail: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- > According to Pete D <no@email.com>: >> "DoN. Nichols" <dnichols@d-and-d.com> wrote in message >>> According to Pete D <no@email.com>: >>>> Canon have their EF-S range that is digital only. Nikon I am not sure >>>> about. >>>> Pentax has their digital only range. >>> So does Nikon -- in the "G" series lenses. >> I am surprised that they will not work on newer film bodies, > Mechanically -- they will. The N90s is an example of that. > However -- the lens does not cover properly to the corners of > full-frame film. Most G-series lenses cover the full frame - only very recent ones, tagget "DX" as well as "G" will not. You are confusing "G" with "DX" in Nikon lens nomenclature. Signature- gisle hannemyr [ gisle{at}hannemyr.no - http://hannemyr.com/photo/ ] ------------------------------------------------------------------------ Sigma SD10, Kodak DCS460, Canon Powershot G5, Olympus 2020Z ------------------------------------------------------------------------ According to Gisle Hannemyr <gisle+news@ifi.uio.no>: > > According to Pete D <no@email.com>: > >> "DoN. Nichols" <dnichols@d-and-d.com> wrote in message [quoted text clipped - 16 lines] > > You are confusing "G" with "DX" in Nikon lens nomenclature. Thanks for the correction. Enjoy, DoN. SignatureEmail: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- > Agreed -- but the 'G' series lenses also are not designed to >cover anything larger than the 1.5 crop factor sensor of the digital >Nikon DSLRs. I believe that this isn't strictly true. It may be true that all recent DX series lenses are also G series. But look at the 24-85mm f/3.5-4.5G ED-IF AF-S Zoom-Nikkor. Look carefully at the Tech Specs, specifically the Picture Angle. The spec includes a coverage angle for 35 mm as well as for DX. http://www.nikonusa.com/template.php?cat=1&grp=5&productNr=2141 Father Kodak According to Father Kodak <dont_bother@IDontCare.COM>: > > Agreed -- but the 'G' series lenses also are not designed to > >cover anything larger than the 1.5 crop factor sensor of the digital > >Nikon DSLRs. > > I believe that this isn't strictly true. So I already learned from the two previous corrections. > It may be true that all > recent DX series lenses are also G series. But look at the 24-85mm > f/3.5-4.5G ED-IF AF-S Zoom-Nikkor. Look carefully at the Tech Specs, > specifically the Picture Angle. The spec includes a coverage angle > for 35 mm as well as for DX. Understood. I should have mentioned "DX", not 'G'. My only example of either is the 18-70mm "kit" lens, and I misremembered which identifier showed it as for the 1.5x crop sensor. My point, however (that Nikon *does* make lenses explicitly for the 1.5x crop factor sensor still stands, even though the designator does not. Enjoy, DoN. SignatureEmail: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- > According to Pete D <no@email.com>: >> Canon have their EF-S range that is digital only. Nikon I am not >> sure about. Pentax has their digital only range. > So does Nikon -- in the "G" series lenses. That is nonsense. The G-series of lenses appeared before before any Nikon digital camera and the G-designation have noting to do with digital. > One interesting feature of the new "G" series lenses is the lack of > an aperture ring. The camera body is expected to command the lens > to the proper aperture -- which makes this lens useless on a film > body In Nikonspeak, "G" just means no aperture ring. They work fine on my Nikon N80 film body. I belive the G-series will work on /all/ Nikon AF film bodies. > -- aside from the feature mentioned in the following paragraph, > which applies to the Nikon lenses for digital as well. >> They have a smaller image circle so can be made smaller and ligher >> and will vignet on a larger sensor camera. The older G-series lenses have a full image circle. Nikon uses "DX" to designate lenses with a smaller image circle. Signature- gisle hannemyr [ gisle{at}hannemyr.no - http://hannemyr.com/photo/ ] ------------------------------------------------------------------------ Sigma SD10, Kodak DCS460, Canon Powershot G5, Olympus 2020Z ------------------------------------------------------------------------ According to Gisle Hannemyr <gisle+news@ifi.uio.no>: > > According to Pete D <no@email.com>: > [quoted text clipped - 13 lines] > > In Nikonspeak, "G" just means no aperture ring. O.K. Thanks. I've only seen the 18-70mm lens and forget which designator indicated which feature. Thanks, DoN. SignatureEmail: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- > On a few occasions, I've seen references to "digital" lenses. These > are lenses that are optimized to have photons hit the digital sensor [quoted text clipped - 14 lines] > it > because this whole "digital lens" thing is just a load of crap? With a Sigma lens, there are "DC" lenses and "DG" lenses. DC lenses are made to be used with digital cameras that do not have a full-frame size sensor (most DSLRs fall into this catagory), DG lenses are "optimized" for digital but can be used on full-frame film and digital SLRs. What makes the DG lenses optimized is the lens coatings. >On a few occasions, I've seen references to "digital" lenses. These >are lenses that are optimized to have photons hit the digital sensor at >a perpedicular angle. Allegedly, lenses optimized to work with digital >sensors would produce better results for a digital camera than a lens >designed originally with film in mind. It seemed to make sense to my >feeble mind. Some of these lense are designed to project a smaller image circle for small sensor digital cameras, so technically they're designed to fit only on digital models. But beyond that, there is nothing special about them. These smaller lenses have a special designation so people will know they are made to work with smaller sensors and may not work properly on a full frame body. Canon uses "EF-S", Nikon uses "DX", etc. >So now I'm wodnering why I don't see Nikon or Canon lenses with these >"digital lens" designations. Is it because these companies are making >compromises for the sake of compatibility with film cameras? Or is it >because this whole "digital lens" thing is just a load of crap? It's a load of crap. Marketing departments love to use the word "digital" for any technology to promote sales, even if that technology is not digital at all. One of the most widely used is "digital speakers" for home theaters, even though speakers are 100% analog by their very nature. I have a couple of lenses that are over 10 years old that were made before DSLRs really existed and they work perfectly fine on my digital camera. I've heard of people using lenses that are 20-30 years old as well without any problems. 8< > I've heard of people using lenses that are 20-30 years old as > well without any problems. Conversely, 'without any problems' does not necessarily imply 'at optimum efficiency' either. >> I've heard of people using lenses that are 20-30 years old as well >> without any problems. > Conversely, 'without any problems' does not necessarily imply 'at > optimum efficiency' either. Granted, but I regularly use an uncoated Takumar 55m f/1.8 from 1972 on a digital camera, and it performs very well, and just as well in terms of sharpness, ghosting, contrast and CA as any "optimized for digital" lens I own - inclusive some expensive fixed focal length lenses. I'd say that beyond being smaller and lighter (because of the smaller image circle of EF-S and DX), "optimized for digital" is bunk. Signature- gisle hannemyr [ gisle{at}hannemyr.no - http://hannemyr.com/photo/ ] ------------------------------------------------------------------------ Sigma SD10, Kodak DCS460, Canon Powershot G5, Olympus 2020Z ------------------------------------------------------------------------ >> I've heard of people using lenses that are 20-30 years old as >> well without any problems. > >Conversely, 'without any problems' does not necessarily imply 'at >optimum efficiency' either. Where did you get the idea that a loss in efficiency isn't a problem? I consider ANY change that produces visible degradation to be a problem. But it doesn't matter if it's at optimum efficiency or not, and I doubt there is any tangible difference. Certainly there is no visible difference between film and digital media using the same lenses, so the lenses all work as intended. I've read that digital lenses have optimized coatings to reduce glare from light reflected from the sensor. Made some sense to me too, until I tested it with my 10 year old glass. There is no validity when compared with older lenses with good coatings that perform just as well on both film and digital cameras. I have seen marketing terminology that "implies" that it's better, but the terms are always equally applicable to any other decent lense. It's like saying that gasoline designed by Ford is for Ford vehicles only, but gas is gas, so it works in any vehicle. Since coated glass exists to reduce glare from reflective surfaces, including other glass surfaces inside the lense, any properly treated and coated lense should perform the same on either format. As I mentioned in my previous post, it's all a marketing ploy to appease the unwashed masses who don't know any better. Making a new customer feel all warm and fuzzy about their new purchase is part of the marketing ploy. And obviously it works. > Certainly there is no visible > difference between film and digital media using the same lenses, so the > lenses all work as intended. Can you cite some references for this? Is this just 35mm, where the sensor is a large distance from the rear element, or does it include compacts, etc..? In regard to the different way a sensor interacts with light compared to film, here's a paper from Dalsa, who I would regard as fairly respected in the field of sensor design: http://www.dalsa.com/dc/documents/Image_Sensor_Architecture_Whitepaper_Digital_C inema_00218-00_03-70.pdf " Microlenses can boost effective fill factor...(but)...the disadvantage of microlenses (besides some additional complexity and cost in fabrication) is that they make pixel response increasingly dependent on lens aperture and the angle of incident photons. At low f-numbers, microlensed pixels can suffer from vignetting, pixel crosstalk, light scattering, diffraction (Janesick, 2), and reduced MTF-all of which can hurt their resolving power. Some of these effects can be minimized by image processing after capture...." > I've read that digital lenses have optimized coatings to reduce glare > from light reflected from the sensor. Made some sense to me too, until I > tested it with my 10 year old glass. There is no validity when compared > with older lenses with good coatings that perform just as well on both > film and digital cameras. So you debunked it by testing one lens? How exactly did you test it, and can we see the results? http://www.outdoorphotographer.com/content/2005/mar/gb_lenses.shtml ..is just one site that refers to a *lot* of examples of lens manufacturers actively changing their designs to combat 'sensor flare' from rear element reflections. > I have seen marketing terminology that "implies" that it's better, but > the terms are always equally applicable to any other decent lense. It's > like saying that gasoline designed by Ford is for Ford vehicles only, > but gas is gas, so it works in any vehicle. But gas *isn't* gas. Unleaded, high octane, diesel? Analogies are just analogies.. and they often bite back. > Since coated glass exists to reduce glare from reflective surfaces, > including other glass surfaces inside the lense, any properly treated > and coated lense should perform the same on either format. Film reflects a different amount of light in a very different way to a sensor. So the conditions have changed, and maybe the lens design has to change also. > As I mentioned in my previous post, it's all a marketing ploy to appease > the unwashed masses who don't know any better. Hyperbole in *either* direction is equally unhelpful. I'm sure there *is* a significant amount of one-upmanship and advertising bullshit tangled up in this, but I also believe that if you apply some sort of rigorous approach to the science of digital imaging and consider all the nuances, then you *will* find differences and issues. And I find it hard to believe that manufacturers would go to all this trouble just as a marketing ploy. Why don't they just claim their lenses control flare better or are sharper? Why bring up a 'ploy' that could be disproven or challenged? And if people like Dalsa say that incident angle is an issue, or that sensor reflections can cause flare, then I'm inclined to believe them. How much of an issue? I don't know. And I hate to add this to the debate, but there's also the dreaded purple-fringing, which is another area where digital varies significantly from film. More at these links, on that and other related issues: http://www.pictureline.com/newsletter/2004/july/purplefringe.html http://www.dl-c.com/discus/messages/36/2357.html?1085412913 http://www.shutterbug.com/features/0305digitally/ An awful lot of pretty highly regarded folk are getting sucked in to this, if it's all a ploy.. 8< > An awful lot of pretty highly regarded folk are getting sucked in to > this, if it's all a ploy.. Many thanks for taking such pains over this post, Mark. >> Certainly there is no visible >> difference between film and digital media using the same lenses, so the [quoted text clipped - 3 lines] >sensor is a large distance from the rear element, or does it include >compacts, etc..? The discussion is about SLR, so no compacts. >In regard to the different way a sensor interacts with light compared >to film, here's a paper from Dalsa, who I would regard as fairly [quoted text clipped - 9 lines] >MTF-all of which can hurt their resolving power. Some of these effects >can be minimized by image processing after capture...." Thanks for backing me up! :-) There's nothing in that white paper which says the lenses for digital sensors require special coatings, designs, or anything else. The paper is discussing sensor issues, specifically micro-lenses, not film versus digital lenses. And now I'm sorry but I have to be harsh - did you actually read any of these links or just cull them from Google and post them here? >> I've read that digital lenses have optimized coatings to reduce glare >> from light reflected from the sensor. Made some sense to me too, until I [quoted text clipped - 4 lines] >So you debunked it by testing one lens? How exactly did you test it, >and can we see the results? No I personally compared results with 8 or 10 lenses from Canon and Nikon ranging in age of over 10 years to a new lense bought only a few months before I did the comparison. I'll grant that it wasn't the most scientific of tests since I was doing it for me and a friend. But when I started, I too believed what I was told and had read about digital sensors causing poor image quality due to reflected light. The purpose of the comparison was to find problems related to using regular lenses on digital bodies and back up the claims. I could not find a single example out of dozens of samples. >http://www.outdoorphotographer.com/content/2005/mar/gb_lenses.shtml >..is just one site that refers to a *lot* of examples of lens >manufacturers actively changing their designs to combat 'sensor flare' >from rear element reflections. Again, most of that just simply states that reflections may occur from the sensor. But since most lenses already have curved surfaces at the rear with multiple coatings to reduce glare, the problem of reflected light isn't an issue. It's noted in the article that lense flare is a far bigger issue and that coatings must be used to deal with it. >> I have seen marketing terminology that "implies" that it's better, but >> the terms are always equally applicable to any other decent lense. It's [quoted text clipped - 3 lines] >But gas *isn't* gas. Unleaded, high octane, diesel? Analogies are >just analogies.. and they often bite back. Whatever...I think you get the point. >> Since coated glass exists to reduce glare from reflective surfaces, >> including other glass surfaces inside the lense, any properly treated [quoted text clipped - 3 lines] >sensor. So the conditions have changed, and maybe the lens design has >to change also. That's what I thought too. My informal testing couldn't find any evidence of it though, and I have been unable to find any conclusive online examples that show digital lenses are somehow special. >> As I mentioned in my previous post, it's all a marketing ploy to appease >> the unwashed masses who don't know any better. [quoted text clipped - 6 lines] >it hard to believe that manufacturers would go to all this trouble just >as a marketing ploy What trouble? They slap the word "digital" on the side of a lense, or in an ad, or on the packaging. Costs them virtually nothing in expenses, but reaps them large rewards in customer satisfaction (warm and fuzzy) and sales revenues. And if there was a benefit of using different coatings, they would simply switch to those coatings for all new lenses and again there is little or no cost involved beyond development. > Why don't they just claim their lenses control >flare better or are sharper? Why bring up a 'ploy' that could be >disproven or challenged? Because that doesn't make consumers feel warm and fuzzy. > And if people like Dalsa say that incident >angle is an issue, or that sensor reflections can cause flare, then I'm >inclined to believe them. How much of an issue? I don't know. It's a non-issue, but it's good for sales to promote it. Dalsa didn't have any proof either, just unspecified claims from the manufacturers. The examples cited are based on marketing information that is already known - coatings on lenses have been around for many years, digital doesn't change that. >And I hate to add this to the debate, but there's also the dreaded >purple-fringing, which is another area where digital varies >significantly from film. Except that CA is a problem of the lense, not the sensor. Purple fringing is a blooming issue within the sensor, and lenses do not affect it. The links you posted have no evidence, tests, or examples showing that digital lenses are special in some way. I took the time to read through all the links because I thought you had some new evidence for me to consider, but the answer to the question if digital lenses are special is still a resounding no. Let's point out the highlights: >http://www.pictureline.com/newsletter/2004/july/purplefringe.html First, this is in regards to purple fringing, not digital lenses. "Tests were also conducted to see if extra or unfocused UV or Infrared was causing site pollution. None of these symptoms alone seemed to be the problem." >http://www.dl-c.com/discus/messages/36/2357.html?1085412913 Just a simple discussion group. No examples, except a mention of purple fringing, which may have been CA, but again is a lense issue. >http://www.shutterbug.com/features/0305digitally/ "According to a Tamron technical rep, the company employs (unspecified) measures to increase corner luminosity or brightness with many Di lenses." The article goes on to test some lenses, but the tests are NOT comparative in regards to film versus digital. They merely mention the claims from manufacturers, and that's it. >An awful lot of pretty highly regarded folk are getting sucked in to >this, if it's all a ploy.. They just follow the manufacturers unsubstantiated claims. All this digital lense stuff is just talk and marketing hype. Consumers absolutely love the word "digital". It's at the point where two identical items can be offered at the same price, but the one that says digital on it will sell better. It's the same with ultrasonic sensor cleaners. They don't really do anything, but since they only cost a few pennies each, putting them in to make their consumers feel warm and fuzzy is a great gimmick for improving sales. Canon jumped on the bandwagon with their XTi/400D, so I think Nikon will be following the herd with their next entry level model and add a sensor cleaner too. But I doubt any of the companies will be wasting our time with cleaners inside high end cameras. Unless they come up with something new that actually works. Long post, but sometimes unvalidated opinions need to be challenged. > >> Certainly there is no visible > >> difference between film and digital media using the same lenses, so the [quoted text clipped - 5 lines] > > The discussion is about SLR, so no compacts. But your comment was all-encompassing. It had *no* provisos. You said "there is no visible difference between film and digital". So there is now one proviso at least - you say it only applies to SLR's... We still don't know if you just mean 35mm - did your 'tests' include other SLR formats? Are there more provisos you will roll out when it suits? > >In regard to the different way a sensor interacts with light compared > >to film, here's a paper from Dalsa, who I would regard as fairly [quoted text clipped - 10 lines] > > Thanks for backing me up! :-) I'm intrigued. How does that back up your comment? I repeat - *you* said "there is no visible difference between film and digital". Dalsa (and they are not alone) list a whole pile of problems with microlens-fitted sensors, and some of these clearly are real. Unless you deny the existence of such things as purple fringing. In which case I think your opinion may be a little out of step with reality. > There's nothing in that white paper which says the lenses for digital > sensors require special coatings, designs, or anything else. No, they didn't bother to spell out the obvious. But given they say "pixel response (is) increasingly dependent on lens aperture and the angle of incident photons", then if I were a lens designer and reasonably intelligent, I would be tempted to infer that if there were things I could do as lens designer to lessen the problems, I should probably consider them. And there *are* things that can be done. If you dispute that, then can you explain things like retrofocus designs and the purpose of multicoating? (O; > The paper > is discussing sensor issues, specifically micro-lenses, not film versus > digital lenses. It is from a very repsected source (see below), it *directly* refers to digital sensors versus film, and how they react differently to light striking them. Nothing to do with lens design...? You have a very tight, dark tunnel of concentration there...(pun intended) > And now I'm sorry but I have to be harsh - did you actually read any of > these links or just cull them from Google and post them here? Given the above comments, you should perhaps take your own advice. I note that you have not offered a countering reference, nor any evidence whatsoever. I shall return the harshness - do you have any understanding of scientific methodologies, or how to do research? > >So you debunked it by testing one lens? How exactly did you test it, > >and can we see the results? > > No I personally compared results with 8 or 10 lenses from Canon and > Nikon ranging in age of over 10 years to a new lense bought only a few > months before I did the comparison. 8 or 10, were there? Which lenses? How did you do it? And the results are not available? Anything at all you can offer from this 'test', or just your word?? > I'll grant that it wasn't the most scientific of tests since I was doing > it for me and a friend. Clearly. (O; > But when I started, I too believed what I was > told and had read about digital sensors causing poor image quality due > to reflected light. And when you finished, you had found that, as far as you could see, there was no difference with those lenses under whatever conditions you had tested. Forgive me for considering that as inconclusive and for deferring to people like Dalsa, Jonathon Sachs, Canon, Nikon, Olympus, Imatest, Norman Koren, Roger Clark and a multitude of others - all of whom are lying to us, or being fooled according to you. > The purpose of the comparison was to find problems related to using > regular lenses on digital bodies and back up the claims. I could not > find a single example out of dozens of samples. Dozens now? - it was 8-10 before.... your numbers are increasing by the second! You haven't named the lenses. You haven't named what tests you did, what sort of targets, what sort of measurements, how you controlled the conditions.. and in fact have hinted it was entirely subjective. That was probably very useful for you and your friend, don't get me wrong - but you have then drawn a very long sword... Again, I am not saying that the differences between film and digital are huge issues, but they are *not* non-existent. When you add them up, you can be talking about *visible* problems, and designers are sensibly taking these issues into account and trying to give us better lenses. Some no doubt are not doing it well, others hopefully are. > >http://www.outdoorphotographer.com/content/2005/mar/gb_lenses.shtml > >..is just one site that refers to a *lot* of examples of lens [quoted text clipped - 5 lines] > rear with multiple coatings to reduce glare, the problem of reflected > light isn't an issue. "Isn't an issue"...? You dismiss it without evidence. Bit of a habit... You accused *me* of not reading these articles, so let's directly quote from it: "Another difference between film and digital is the relatively mirror-like surface of image sensors." "In some cases, the sensors' smooth face can reflect light back through the rear lens elements" "The Canon L-series...have optimized lens element shapes and anti-reflection coatings to minimize or eliminate these ghosts." "Canon and Nikon also...subtly curve the ..front filters on their super-telephoto lenses. The filters' new meniscus shape disperses the reflections from the image sensor that would otherwise bounce off the rear of the filter and straight back onto the sensor's face." So, yes, that particular page is mainly about one thing. But the inference seems pretty clear, to me at least. > It's noted in the article that lense flare is a far bigger issue and > that coatings must be used to deal with it. Now that sentence gives me/you a problem. Firstly, yes, *of course* 'normal' flare is a bigger issue, that is stating the obvious. No argument there. But the problem for you, Bill, is that as far as I can see, it *DOESN'T* say that *anywhere* on the page. I would ask you to now quote the words that you are referring to, when you say "It's noted in the article that lense flare is a far bigger issue". Where EXACTLY does it say, or imply, that? Given you accused *me* of not reading the links, I think that is a fair request, is it not? Otherwise one might suggest you were not only selectively quoting, but making it up as you go along. > >> I have seen marketing terminology that "implies" that it's better, but > >> the terms are always equally applicable to any other decent lense. It's [quoted text clipped - 5 lines] > > Whatever...I think you get the point. No, I don't get the non-existent point. Invalid analogies are useless. To play your game, why not go down to your nearest airport and see how an aircraft goes if you fill it with 'gas'. When it eventually falls out of the sky, is that like what will happen when you put a non-digital lens on a digital SLR? I think you get the point. If not, I'll spell it out - it's a meaningless attempt at an analogy. > >Film reflects a different amount of light in a very different way to a > >sensor. So the conditions have changed, and maybe the lens design has [quoted text clipped - 5 lines] > been unable to find any conclusive online examples that show digital > lenses are somehow special. Emphasis on the word *informal*. I doubt if you will see such tests, partly because it is not at all simple to do. I've not got the time or inclination to go through all the reasons I can think of, but here's a few - how would you *directly* compare differently designed lenses? How would you replicate enough variation in shooting conditions (eg into sun etc), using two similar bodies (film/dig) but still ensuring the conditions didn't change between shots? Would it be in the manufacturers interest to show up problems with older lenses? Why would someone do it - will they make money from this highly expensive comparison? How many of the hundreds/thousands of potential lens/sensor/aperture/scene combinations would you test? That's just the first few issues I came up with.. > >> As I mentioned in my previous post, it's all a marketing ploy to appease > >> the unwashed masses who don't know any better. [quoted text clipped - 12 lines] > large rewards in customer satisfaction (warm and fuzzy) and sales > revenues. And brochures, and impressive (if highly exaggerated) diagrams and presentations, design costs/tooling.. do you really think this sort of stuff costs "virtually nothing" and that no-one except a few very 'wise' usenetters will spot the subterfuge? > > Why don't they just claim their lenses control > >flare better or are sharper? Why bring up a 'ploy' that could be > >disproven or challenged? > > Because that doesn't make consumers feel warm and fuzzy. Your opinion. > > And if people like Dalsa say that incident > >angle is an issue, or that sensor reflections can cause flare, then I'm [quoted text clipped - 4 lines] > Dalsa didn't have any proof either, just unspecified claims from the > manufacturers. Sigh. Do you not know who Dalsa are? They ARE (very serious) manufacturers, and are not your average tinpot company. See below. > Except that CA is a problem of the lense, not the sensor. Yes. So? I didn't even bring up CA.. > Purple fringing is a blooming issue within the sensor, and lenses do not > affect it. Except for the sad fact that the angle of incidence comes into play again, and that people often mistake PF for CA, and it all gets tangled together anyway with many lens/sensor combinations. If the lenses do not affect it, how is it that you very rarely see PF in the centre of an image? (First googled link: http://www.sd3.info/pf828/Sony_828_Purple_Fringe_Analysis.html Are you suggesting that the sensor has less purple fringing 'potential' in the middle, and more on the periphery? > The links you posted have no evidence, tests, or examples showing that > digital lenses are special in some way. In your opinion. And compared to your anecdotes without detail, and no links at all. > I took the time to read through > all the links Well, given your comments above and your misreading (or invention), I have to wonder... > because I thought you had some new evidence for me to > consider, but the answer to the question if digital lenses are special > is still a resounding no. Again, in your opinion. > >http://www.pictureline.com/newsletter/2004/july/purplefringe.html > > First, this is in regards to purple fringing, not digital lenses. Sigh - this whole thread is about whether lenses need to be/are designed differently for digital sensors. Digital sensors show purple fringing, and it is worse at the periphery, where incident angle is greatest. Different lenses show different amounts of PF on the same sensor. What does that tell you???? And again, I quote: "To date there is no clear single item that is responsible for purple fringing. We do know that is most likely to happen when apertures of greater than f/4 are used, when a wide angle of 28mm (or equivalent) or wider is used and when the subject to background contrast is high." And you say it isn't about the lenses???? (O: > "Tests were also conducted to see if extra or unfocused UV or Infrared > was causing site pollution. None of these symptoms alone seemed to be > the problem." Strange how your selective quote didn't include the bit above, and note the word ALONE... > >http://www.dl-c.com/discus/messages/36/2357.html?1085412913 > > Just a simple discussion group. No examples, except a mention of purple > fringing, which may have been CA, but again is a lense issue. Hang on, a minute ago you were arguing it was *not* about the lens, now you have jumped sides? And do you have any idea who Jonathan Sachs is? Obviously not. Like you didn't know that Dalsa is a *manufacturer* of high end sensors for very specialised use (eg aerial photography, high-res cinematography, medium format, etc). Dalsa are renowned for their innovation in this field. > >http://www.shutterbug.com/features/0305digitally/ > > "According to a Tamron technical rep, the company employs (unspecified) > measures to increase corner "luminosity" or brightness with many Di > lenses." (how is that quote relevant?) How about these quotes instead: "it's important to understand the major differences between film and digital sensors." "A silicon sensor (and its protective glass cover) is far more reflective than photographic film." "The three-dimensional structure of a digital sensor demands that light strike the entire surface at a 90Þ angle for the best results." "When using conventional lenses..the light strikes the film plane at an increasingly oblique angle, as you move toward the edge of the image. I wouldn't lose sleep over that, but the problem is more significant in digital capture particularly with wide angle lenses used at wide apertures." "it's worth noting that the camera manufacturers have also developed digitally optimized lenses, although not all such lenses are labeled accordingly." (O; Funny how my quotes seem to convey a quite different opinion to yours. Feel free, Bill, or anyone, to point out if (and how) they are out of context. > The article goes on to test some lenses, but the tests are NOT > comparative in regards to film versus digital. They merely mention the > claims from manufacturers, and that's it. Which you dismiss, summarily and arbirtrarily. OK, it's your choice. > They just follow the manufacturers unsubstantiated claims. Again, several of them ARE the manufacturers! > It's the same with ultrasonic sensor cleaners. They don't really do > anything Ah yes, here we go again. Another one-liner dismissal, and the introduction of a new (old) topic to try to win back the momentum. Tell that to reviewers like Jeff Keller: "Now I can't tell you how well the (Sony anti-dust) system works, but I didn't have any trouble with dust during my weeks with the camera -- unlike most other D-SLRs that I've tested." And most folks think the Sony system isn't as good as the Olympus. Ah yes, more fools. Bill knows better. I won't bother with further quotes, because more one-liners will follow. > but since they only cost a few pennies each Ultrasonic cleaning only costs a few pennies? Maybe once it's developed and mass-produced.. (O; > Canon jumped on the bandwagon with their XTi/400D More fools. > so I think Nikon will > be following the herd with their next entry level model and add a sensor > cleaner too. Yes, they are. More fools. > But I doubt any of the companies will be wasting our time > with cleaners inside high end cameras. Unless they come up with > something new that actually works. Now you say *if* it works it is a good thing? I give up. >8 or 10, were there? Which lenses? How did you do it? And the >results are not available? Anything at all you can offer from this >'test', or just your word?? Like I said, the comparative tests were for our benefit. I didn't anticipate debating the concept of "digital lenses". Suffice it to say that I did real world evaluations, looking for resolution, contrast, ghosting, and flare. I could find no difference between film and sensor image samples. >And when you finished, you had found that, as far as you could see, >there was no difference with those lenses under whatever conditions you >had tested. Forgive me for considering that as inconclusive and for >deferring to people like Dalsa, Jonathon Sachs, Canon, Nikon, Olympus, >Imatest, Norman Koren, Roger Clark and a multitude of others - all of >whom are lying to us, or being fooled according to you. I offered my personal experiences, and if you don't want to believe me, fine. You can believe the marketing departments if you want...I'll continue to take anything they say with a grain of salt. >>> I've heard of people using lenses that are 20-30 years old as >>> well without any problems. >> Conversely, 'without any problems' does not necessarily imply 'at >> optimum efficiency' either. > > Where did you get the idea that a loss in efficiency isn't a problem? Where did I say that? Perhaps your specs need new lenses? ;-) > I consider ANY change that produces visible degradation to be a problem. 8< I agree. > Where did you get the idea that a loss in efficiency isn't a problem? > I > consider ANY change that produces visible degradation to be a problem. Are there really lenses that you've been able to test that were identical in all respects except for this? And were you able to test both lenses in all possible lighting conditions, at all apertures, subject distances, and focal lengths? It seems incredibly unlikely to me that anyone who doesn't work in a lens factory would have been able to do the kind of testing necessary to say with any kind of certainty that there is never any situation in which this makes a difference. > Certainly there is no visible > difference between film and digital media using the same lenses Visible in a 4x6 print, or blown up to a size corresponding to a 100% crop on a computer monitor? Either way, that might be useful as a quick and dirty test, but it wouldn't give the complete picture. For one thing, of course the inherent differences in color response, dynamic range and so forth could very well mask the differences we are talking about here. And for another, it could well be that a better optimized lens would have produced even *better* results in some ways on the digital sensor than with the film. That said, I'd certainly agree the differences aren't important for most people msot of the time, and I'm not claiming to have seen any direct evidence of it, either. --------------- Marc Sabatella marc@outsideshore.com Music, art, & educational materials Featuring "A Jazz Improvisation Primer" http://www.outsideshore.com/ >> Where did you get the idea that a loss in efficiency isn't a >> problem? I consider ANY change that produces visible degradation to [quoted text clipped - 4 lines] > test both lenses in all possible lighting conditions, at all > apertures, subject distances, and focal lengths? Obviously we had limitations because we didn't want to spend hundres on film for the comparisons, but we did a fairly wide range of typical conditions, like day and night shots, high contrast, wide open and stopped down, etc. You have to remember that we disagreed on the concept, so we tried lots of extremes in order to prove each others point. It didn't work. :-) >> Certainly there is no visible >> difference between film and digital media using the same lenses > > Visible in a 4x6 print, or blown up to a size corresponding to a > 100% crop on a computer monitor? All images were compared on the computer using Photoshop - we didn't make prints to reduce costs. Negatives were scanned using a Nikon Coolscan at 4000 dpi if I remember right. > Either way, that might be useful as a quick and dirty test, but it > wouldn't give the complete picture. For one thing, of course the [quoted text clipped - 3 lines] > have produced even *better* results in some ways on the digital > sensor than with the film. I'm aware that there are theoretical differences, but the comparison tests were done to see if it made any visible differences when examined closely. I figured there had to be some difference, but no joy there. We were looking for digital differences compared to film, but we tested a couple of "digital" lenses by mounting the 12-24 and 18-70 lenses on an F100 for fun, and the only obvious issue was severe vignetting. Ignoring that aspect, the images were great. > That said, I'd certainly agree the differences aren't important for > most people msot of the time, and I'm not claiming to have seen any > direct evidence of it, either. What minor differences may exist are not visible, that was the point of our little comparison tests. Perhaps under tighter controlled tests using resolution and colour charts there might be something of note, but if it doesn't show in real world photos, who cares. >>> Certainly there is no visible >>> difference between film and digital media using the same lenses [quoted text clipped - 5 lines] > make prints to reduce costs. Negatives were scanned using a Nikon > Coolscan at 4000 dpi if I remember right. Now you've introduced yet *another* variable: the scanner. You have two *very* different images - one from film, one from a digital sensor; one displayed in native digital form, one that has been printed and then scanned. There would already be so many differences between these two images that there is *no way* you could expect to see the sorts of subtle differences we are talking about here. Again, the only way to prove your hypothesis would be to perform a controlled experiment, which would mean two lenses on the same camera, converted and displayed in the same way, where the *only* difference was the coating. > What minor differences may exist are not visible Not visible to *you* after by comparing images that were apples and oranges to begin with - again, not a particularly convincing experiment. --------------- Marc Sabatella marc@outsideshore.com Music, art, & educational materials Featuring "A Jazz Improvisation Primer" http://www.outsideshore.com/ >> All images were compared on the computer using Photoshop - we >> didn't make prints to reduce costs. Negatives were scanned using a [quoted text clipped - 4 lines] > sensor; one displayed in native digital form, one that has been > printed and then scanned. Please read the full thread. There were no prints involved...I already mentioned that. The Coolscan is a negative film scanner...it doesn't get much better (at our price points) when converting film to digital format. > There would already be so many differences between these two images > that there is *no way* you could expect to see the sorts of subtle > differences we are talking about here. Again, the only way to prove > your hypothesis would be to perform a controlled experiment, which > would mean two lenses on the same camera, converted and displayed in > the same way, where the *only* difference was the coating. Well then forget about film/digital comparisons because it's NOT possible to have a completely identical comparison. Film is an analog medium and there must be a conversion to digital at some point to compare on the computer. As for old/new lense side-by-side comparisons, I already covered that and there were no visible differences. But since you seem insistent that I'm incompetent, just forget about the whole thing. You're right, digital lenses are the best and everyone should take a hammer to their old lenses immediately. Or not. :-p > Well then forget about film/digital comparisons because it's NOT > possible to have a completely identical comparison. Film is an analog > medium and there must be a conversion to digital at some point to > compare on the computer. Well, you could get a lens that is produced in both versions, such as the Tamron 90mm macro (which comes in two versions, identical except for the coating), and use both of them on the same camera. If you found no differences, of course, one could still claim that you simply did not test under the conditions that would bring them out. A bit tricky to prove the nonexistence of something with experiments. eg prove to me that there is not a Peugeot 106 Rallye in orbit around alpha centauri as we speak--even if you could go there, I can claim it is on the other side, and if you clone yourself to check both sides and so on, I claim it just gets smaller and smaller so you all keep missing it etc. [Reasonable people would, at some point, concede that there is no such thing orbiting the star; but there is no demand for reasonableness here.] Ah, the perils of induction... > As for old/new lense side-by-side comparisons, I already covered that > and there were no visible differences. > > But since you seem insistent that I'm incompetent, just forget about > the whole thing. You're right, digital lenses are the best and > everyone should take a hammer to their old lenses immediately. This guy might be able to offer some tips on how to do a proper job: http://www.hermes.net.au/bayling/repair.html > Please read the full thread. There were no prints involved...I already > mentioned that. You're right; I missed that. Still, comparing an image shot on film to one shot on a digital sensor is apples to oranges. There should have been differences that would have been *obvious*, and it would be impossible to tell which of these differences were due to which issues. > Well then forget about film/digital comparisons because it's NOT > possible to have a completely identical comparison. That was my point, yes. > As for old/new lense side-by-side comparisons, I already covered that > and there were no visible differences. I must have missed that too. *Exact* same lenses except for the coating? I'd be curious to see those images... > But since you seem insistent that I'm incompetent, just forget about > the whole thing. You're right, digital lenses are the best and > everyone should take a hammer to their old lenses immediately. Never said that. I use film lenses too. They work fine. Whether or not digitally optimzied ones would work *better* or not remains an open question, and I see absolutely no reason to doubt the folks who actually design and build lenses for living based solely the word of a random nesgroup poster, much less one who insists a film-versus-digital comparison is valid enough to bother mentioning. --------------- Marc Sabatella marc@outsideshore.com Music, art, & educational materials Featuring "A Jazz Improvisation Primer" http://www.outsideshore.com/ >> So now I'm wodnering why I don't see Nikon or Canon lenses with these >> "digital lens" designations. Is it because these companies are making [quoted text clipped - 7 lines] > the most widely used is "digital speakers" for home theaters, even > though speakers are 100% analog by their very nature. I just bought a digital tripod to go with a new all digital carrying case and lens hood. <s.> Yes, much of it is marketing crap. But lenses that can be made cheaper for small sensor sizes (for most Canon and all Nikon DSLRs) are properly given a digital name as they'll work or fit only on DSLRs. Signaturejohn mcwilliams >I just bought a digital tripod to go with a new all digital carrying >case and lens hood. <s.> Does it actually say "digital" on the tripod? >>I just bought a digital tripod to go with a new all digital carrying >>case and lens hood. <s.> > > Does it actually say "digital" on the tripod? I have a Manfrotto Digi Tripod, nice little tripod. >>> I just bought a digital tripod to go with a new all digital carrying >>> case and lens hood. <s.> >> Does it actually say "digital" on the tripod? >> > I have a Manfrotto Digi Tripod, nice little tripod. Nah. I made that up. Although I might make up some stickers myself. Did I mention I got a great deal on a digital shirt the other day?? Signaturejohn mcwilliams >>>> I just bought a digital tripod to go with a new all digital carrying >>>> case and lens hood. <s.> [quoted text clipped - 3 lines] > Nah. I made that up. Although I might make up some stickers myself. Did I > mention I got a great deal on a digital shirt the other day?? I distinctly recall audio speakers being marked "Digital Ready," back when CDs were first introduced. One advertiser even went to far as to show how the allegedly purer sine waves produced from digital sources could overtax speakers' ability to reproduce such pure tones! >>>>> I just bought a digital tripod to go with a new all digital carrying >>>>> case and lens hood. <s.> [quoted text clipped - 8 lines] > show how the allegedly purer sine waves produced from digital sources > could overtax speakers' ability to reproduce such pure tones! "audiophiles" are even easier to sell stuff to than "photographers! LOL >>I distinctly recall audio speakers being marked "Digital Ready," back >>when CDs were first introduced. One advertiser even went to far as to >>show how the allegedly purer sine waves produced from digital sources >>could overtax speakers' ability to reproduce such pure tones! > > "audiophiles" are even easier to sell stuff to than "photographers! LOL When I bought my first DVD player, I went into best buy to buy an optical cable to connect the dvd player to the surround amp. I picked up a reasonably priced cable. A sales kid came up and said I really needed to get this ZZZ brand of cable (forget the brand) that was several times more expensive. He said it gave much better sound. I replied "What, it transmits better ones and zeros?" He didn't understand. I bought the cheap optical cable and it works just fine. Roger >>>> I just bought a digital tripod to go with a new all digital carrying >>>> case and lens hood. <s.> [quoted text clipped - 5 lines] > Nah. I made that up. Although I might make up some stickers myself. Did > I mention I got a great deal on a digital shirt the other day?? light emitting fabric: <http://www.research.philips.com/newscenter/pictures/050902-phottext.html> : - ) >>>>> I just bought a digital tripod to go with a new all digital carrying >>>>> case and lens hood. <s.> [quoted text clipped - 8 lines] > light emitting fabric: > <http://www.research.philips.com/newscenter/pictures/050902-phottext.html> Now there's something you can really get your hands on.... SignatureJohn McWilliams > On a few occasions, I've seen references to "digital" lenses. These > are lenses that are optimized to have photons hit the digital sensor at > a perpedicular angle. That would be a neat trick, just not possible other than the most central pixel (or three). > Allegedly, lenses optimized to work with digital > sensors would produce better results for a digital camera than a lens > designed originally with film in mind. It seemed to make sense to my > feeble mind. The only optimization is less glass as the sensors are smaller. Some also have anti reflective coatings on the rear element so that a refelected image of the sensor does not appear in the image or cause loss of contrast. I've yet to see any evidence that this is of any value at all. > So now I'm wodnering why I don't see Nikon or Canon lenses with these > "digital lens" designations. Is it because these companies are making > compromises for the sake of compatibility with film cameras? Or is it > because this whole "digital lens" thing is just a load of crap? Pretty much. There is some evidence that there may be "matching" of certain lenses with certain MTF values to certain sensor densities (eg: Chasseur d'Images tests show some lens/camera combos just work better than others), but on the whole, just relax, asemble a good kit and get out there and shoot. Cheers, Alan. Signature-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm -- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm -- [SI] gallery & rulz: http://www.pbase.com/shootin -- e-meil: Remove FreeLunch. According to Alan Browne <alan.browne@FreeLunchVideotron.ca>: > > On a few occasions, I've seen references to "digital" lenses. These > > are lenses that are optimized to have photons hit the digital sensor at > > a perpedicular angle. > > That would be a neat trick, just not possible other than the most > central pixel (or three). But *most* lenses for SLR bodies -- digital or not -- do reduce the angle of incidence of the light from the lens even out to the corners of the sensor. This is in part a function of the "reverse telephoto" design of most wide angle lenses -- for film or digital. There are exceptions -- but those usually would require locking the mirror up to allow them to mount on the body without breaking the mirror. An example is the old Nikon 8mm Fisheye lens, which did require such mirror lock-up, and which is explicitly listed among the "do not mount" lenses in at least the D70's manual -- and probably on *all* Nikon DSLRs. [ ... ] > > So now I'm wodnering why I don't see Nikon or Canon lenses with these > > "digital lens" designations. Is it because these companies are making [quoted text clipped - 8 lines] > others), but on the whole, just relax, asemble a good kit and get out > there and shoot. Agreed. Enjoy, DoN. SignatureEmail: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- > There are exceptions -- but those usually would require locking > the mirror up to allow them to mount on the body without breaking the > mirror. An example is the old Nikon 8mm Fisheye lens, which did require > such mirror lock-up, and which is explicitly listed among the "do not > mount" lenses in at least the D70's manual -- and probably on *all* > Nikon DSLRs. It is in the D200 manual, too. But I wonder; the D200 does have mirror lockup.... > On a few occasions, I've seen references to "digital" lenses. These > are lenses that are optimized to have photons hit the digital sensor at [quoted text clipped - 5 lines] > So now I'm wodnering why I don't see Nikon or Canon lenses with these > "digital lens" designations. Canon tries to solve this problem by micro lenses on the sensor. Canon does have "digital" lenses that covers a smaller image, EF-S. And new Canon lenses, both EF-S and EF, have new anti-reflection coatings for the digital sensors. And the new lenses avoid flat lens element surfaces, also to reduce the sensor reflection problem. Although new EF lenses are compatible to film, they are designed mainly for digital. http://digitcamera.tripod.com/#slr > On a few occasions, I've seen references to "digital" lenses. These > are lenses that are optimized to have photons hit the digital sensor at [quoted text clipped - 7 lines] > compromises for the sake of compatibility with film cameras? Or is it > because this whole "digital lens" thing is just a load of crap? It's hard to tell. Canon is the only maker using FF sensors and they don't (apparently) make "dedicated digital lenses." Some other makers do, but they don't make FF sensors. Now, comparing a FF (SLR) lens against a digital lens does not guarantee you'll see a superior image fromt the so-called digital lens because you are likely (unless you own a FF Canon) only using the centre portion of the light cone from a FF lens anyway. Any aberrations cause by it not being "digital" would in most cases be handled by not using the outer, more aberration light ray bundles. However, if a lens has a very shallow angle of entry for the light rays when they hit the sensor, you can probably see the issues this might cause. Not only does the sensor have pixel wells and microlenses, it also has a few layers of filters and covers in front of it. There is no telling how they'll react unless you had exact design parameters to work from. The best thing to do is to test, if at all possible before buying. >> On a few occasions, I've seen references to "digital" lenses. These >> are lenses that are optimized to have photons hit the digital sensor at [quoted text clipped - 10 lines] > It's hard to tell. Canon is the only maker using FF sensors and they > don't (apparently) make "dedicated digital lenses." Really, what are EF-S lenses? EF-S lens mount -- exclusively for EOS 20D and Digital Rebel bodies http://www.usa.canon.com/consumer/controller?act=ModelDetailAct&fcategoryid=148& modelid=10510 > >> On a few occasions, I've seen references to "digital" lenses. These > >> are lenses that are optimized to have photons hit the digital sensor at [quoted text clipped - 13 lines] > Really, what are EF-S lenses? EF-S lens mount -- exclusively for EOS 20D and > Digital Rebel bodies A lens made to support a smaller image circle is not "digital." If Canon also designed them to send the outgoing light as perpendicular to the rear element as possible and also included better control of CA, then they would be considered digital. > http://www.usa.canon.com/consumer/controller?act=ModelDetailAct&fcategoryid=148& modelid=10510 >> >> On a few occasions, I've seen references to "digital" lenses. These >> >> are lenses that are optimized to have photons hit the digital sensor [quoted text clipped - 23 lines] > >> http://www.usa.canon.com/consumer/controller?act=ModelDetailAct&fcategoryid=148& modelid=10510 Whatever! >>>> On a few occasions, I've seen references to "digital" lenses. These >>>> are lenses that are optimized to have photons hit the digital sensor at [quoted text clipped - 13 lines] > > A lens made to support a smaller image circle is not "digital." A lens that is made solely for a digital camera is pretty digital, Richie. Signaturejohn mcwilliams >> A lens made to support a smaller image circle is not "digital." > > A lens that is made solely for a digital camera is pretty digital, > Richie. Well, you can presumably also use these lenses on a APS-C *film* SLR, should you happen to have one... --------------- Marc Sabatella marc@outsideshore.com Music, art, & educational materials Featuring "A Jazz Improvisation Primer" http://www.outsideshore.com/ >>>A lens made to support a smaller image circle is not "digital." >> [quoted text clipped - 3 lines] > Well, you can presumably also use these lenses on a APS-C *film* SLR, > should you happen to have one... My Minolta Vectis S-1 only uses Vectis lenses. Not even the Maxxum ones. > >> A lens made to support a smaller image circle is not "digital." > > [quoted text clipped - 3 lines] > Well, you can presumably also use these lenses on a APS-C *film* SLR, > should you happen to have one... Nikon says their DX lenses cannot be used on an APS-C camera. They are lying. I have done it. > >>>> On a few occasions, I've seen references to "digital" lenses. These > >>>> are lenses that are optimized to have photons hit the digital sensor at [quoted text clipped - 15 lines] > > A lens that is made solely for a digital camera is pretty digital, Richie. So has anyone tested Canon's "digital" lenses against their SLR legacy lenses on a 350 or 30D? It would be interesting to see which would work better at widest apertures. > On a few occasions, I've seen references to &quo |
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