Yes you did, and it turned out to be a good fit for Bill.
I find that the best full frame digital is about the same quality as 645 film, maybe very slightly less. That assumes a good tripod and mirror lockup. 645 digital is awesome, but also $16000. Film camera resolution is a function of both lens resolution and film resolution, which depend on and affect contrast. Digital is a bit different, more or less giving you the minimum of lens resolution or pixel resolution. The pixel game can become meaningless as lens resolution becomes a factor. A very good general purpose lens will only resolve 120 lines per mm for a high contrast subject. Most resolve less. For a 24X36 sensor, that's only 2880X4320, or 12.4 megapixels. The combination of film and lens usually only gets you about 80 lines per mm, maybe 95 with the best equipment and common film.
Originally Posted by Diapositivo
so basically there is very little to none, as far as R&D goes on new emulsions.
As long as there is some, its better than none at all. At least it seems ADOX is coming out with new films. I would love to get my hands on some Silvermax
+1 - I wonder when it will be available?
Originally Posted by madgardener
The idea that resolution is limited by lens resolution and that the good general purpose lens will only resolve 120 lines per mm (line pairs, probably) would lead IMO, following this reasoning, to saying that FF digital cameras with more than 12.4 mp don't have a higher resolution than those with 12.4 mp. If the lens doesn't resolve more than 120 lp/mm, and that must be true for digital and film, why would FF digital camera have so many pixel?
Originally Posted by nworth
(it goes without saying that all this reasoning implies tripod, mirror lock-up etc).
That seems to be contradicting not just what the industry does (that might be due to marketing hype and consumer irrationality, although I don't think a consumer of a 4000 Euro camera behaves irrationally often) and the general experience of photographers (who do use high-mp sensors mainly to be able to crop the image without going below a certain mp threshold, which means it does make a difference) but also the original affirmation.
I don't understand how this affirmation would stand with the other, "I find that the best full frame digital is about the same quality as 645 film, maybe very slightly less". It is my impression that according to the "120 lines per mm" reasoning, a FF (24x36) digital should not go beyond 12.4 mp (your figure, unless I misunderstand what you say) and I do believe that a scan from a 6x4.5 film image can give you much, much more than that.
You seem to apply your "120 lp/mm reasoning" only to scan from film and not to FF digital.
My affirmation that I do get more than 20mp of real resolution from film stems from daily "pixel peeping" at my scans, for professional reasons (I have to inspect at real pixel size any image that I send to agencies). Sometimes I "blow up" details so that each pixel is a "square" on the monitor, to see how the pixels build the image and if there is some "wasted", redundant pixel, and I can clearly see oblique lines and edges where all pixels "play a role".
If the real resolution were lower than the nominal resolution (given by the pixel dimensions) I would see clusters of pixels with basically the same value where I should instead see an edge, the typical case would be oblique lines where I should see a saw edge. When you inspect images at real pixel size (or, let's say, at 1000% pixel size or so, so that you see any pixel as a solid block) you can clearly see if the real resolution matches the nominal resolution.
More in general, "resolution" is a different concept than resolving line pairs on a mire and this kind of tests do have a role in assessing lens performance but should never be taken as if they were "science". For instance, the general lens has a much better behaviour when focused at infinite than when focused at let's say 1 metre but, as you imagine, resolution patterns are photographed at 1 m (or 2 or what) not at infinite.
When I have time and if anybody is interested (being an hybrid point) I can post some very high magnification crops showing how "no pixel is wasted" in my 4000 ppi scans which leads to a true 20mp resolution from a 135 film. The proof is in the pudding, reasoning about theoretical resolution and lp/mm is no pudding.
As a side note I would like to stress that I scan my images with 16 passes for each location and 2 overall passes with 2 lamp intensities ("multiexposure") so that each pixel is actually the result of 32 passes by the scanner. That "squeezes" 20mp of real useful non-duplicated pixels out of my slides (tripod, mirror lock-up, very good Minolta fixed focal length lenses).
I can see them and all the mathematics in the world will not convince me that my system does not reach that resolution . Too much lp/mm reasoning leads to the situation where to two Dominicans find themselves when Galileo invites them to look inside the telescope to see the "Medicean planets" and the two Dominicans refuse to look because philosophy is superior to sensorial experience, you know*.
* That's a scene from "Life of Galileo" by Brecht, I don't deem it unlikely something like that really happened.
*** EDIT. Mmh, I looked at a table with lp/mm resolution expressed as ppi resolution.
It says that 80 lp/mm (which you indicate as achievable with good lens, good film and good technique) equals 4096 ppi. So I do accept that my scans have a resolution of 80 lp/mm.
But it follows as a consequence that they do yield > 20mp on 135!
Last edited by Diapositivo; 09-20-2012 at 05:27 AM. Click to view previous post history.
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It was said that samples will be handed out at this photokina. You can order them at fotoimpex as well. Film and developer are marked as being on stock.
Originally Posted by Pioneer
I am doing lens, film, developer (and lately sensor) tests for more than 20 years now, on a scientific basis.
Running a private, non-profit optic lab and a network of experienced photographers working on these subjects. We have more than 7000 test shots here and have tested almost all films of the market during the years.
So I certainly can give you exact answers.
That is not true. It is an internet myth mostly spread by people who have never did proper tests by themselves.
Originally Posted by nworth
So let’s have a look at the test results of those who have done very detailed, scientific tests:
Zeiss published system resolution (Zeiss lens + film) values in their camera lens news 17, 19, 20, 24 and 30. Object contrast 1:32 (five stops). Some examples:
Velvia 50: 160 lp/mm
Velvia 100F: 170 lp/mm
Acros 100: 160 lp/mm
T-Max 100: 180 lp/mm
Agfa APX 25 : 200 lp/mm
Agfaortho 25 : 250 lp/mm
Spur Orthopan UR: 400 lp/mm (with 25mm ZM Biogon at f4; 400 lp/mm is the diffraction limit of white light at f4).
Under the same test conditions with the same object contrast and the same Zeiss lenses a Nikon D800E resolve about 105 lp/mm (that is the Nyquist frequency of its sensor, which is the physical resolution limit of a 35 MP 24x36 sensor).
160 lp/mm with Velvia 50 is the value Fuji has published for this film for an object contrast of 1:1000 (10 stops). The resolution values Fuji has published are very conservative, especially the ones of their color films. I've seen results from a collegue who achieved even higher results at medium contrast than Fuji has published for high contrast.
That is all right and not a contradiction because:
Resolution is dependant on object contrast, but it is not a linear relation, but following "the law of diminishing returns". It is an asymptotic curve.
It doesn't matter much whether you have 6 or 10 stops object contrast, the resolution is almost the same.
But it does matter whether you have 0,5 or 2 stops object contrast. In this range there is an almost linear relation (see camera lens news no. 30 for further details). In this low contrast range up to 1,5 stops the modern 24 MP and 35 MP 24x36 sensors have a very good resolution performance and are better than most films. But from 1,5 stops on and higher, in the medium and higher contrast range, modern films (especially color reversal films, tabular grain BW films and of course microfilms), show a significantly higher resolution. Because they are not limited by the Nyquist frequency like digital sensors.
Tests from our team:
We have tested all the films with an relative low object contrast of 1:4 (two stops). Lenses were Nikkor AI-S 1,8/50 (long barrel version) and Zeiss ZF 2/50 at f5,6 (and some others as well).
Both lenses have the same performance in the center at f4 and f5,6, but the Zeiss is generally better at the corners and at f2.
Some test results from our resolution tests (Nikon F6, MLU, MC-30, 1/250s, focus bracketing, Zeiss ZF 2/50, f5,6, Nikkor AI-S 1,8/50, object contrast 1:4; Berlebach Report 3032; the first resolution value represents the number of clearly separated lines, the second one the resolution limit where still a contrast difference can be seen):
Adox CMS 20 / Spur Orthopan UR developed in: Spur Nano Edge, Spur Nanospeed UR, Spur Modular UR, Adotech: 240 - 260 Lp/mm
That is the physical diffraction limit for white light at f5,6 !
Agfa Copex Rapid; ISO 40/17°; Spur Modular UR New: 165 – 180 Lp/mm
TMX, developed in HRX-3: 135 - 150 Lp/mm
Retro 80S, HRX-3, ISO 25/15°: 135 – 145 lp/mm
Delta 100, HRX-3: 130 – 140 lp/mm
Acros 100, HRX-3: 115 – 130 lp/mm
Pan F+, HRX-3: 110 – 130 lp/mm
Fuji Velvia 50: 110 – 125 Lp/mm
Fuji Sensia 100: 120 – 135 Lp/mm
Fuji Provia 100F: 120 – 135 Lp/mm
Fuji Astia 100F: 120 – 135 Lp/mm
Fuji Velvia 100: 125 – 140 Lp/mm
Fuji Velvia 100F: 125 – 140 Lp/mm
Kodak E100G: 120 – 135 Lp/mm
Kodak Elitechrome 100: 120 – 135 Lp/mm
Fuji Provia 400X: 105 – 115 Lp/mm
Fuji Superia Reala 100: 105 – 115 Lp/mm
Fuji Pro 160 C: 100 – 115 Lp/mm
Kodak Ektar: 90 – 105 Lp/mm
We’ve further done all the relevant tests in the following imaging chain: Optical printing, slide projection, scanning (both with 4000ppi semi-professional scanners and high-end drum scanners).
Optical printing and slide projection delivers by far the the highest resolution. With excellent lenses you can transfer the above listed resolution values with only a minimal (not relevant) loss onto paper and on the projection screen.
The resolution loss with high-end drum scanners (we’ve tested Imacon X5 and ICG 370) is significant, the resolution performance is worse compared to optical printing with APO enlarging lenses and slide projection.
The biggest resolution loss and worst performance delivered the Nikon Coolscan 5000 scanner.
It’s effective resolution limit is 65-70 lp/mm.
Tests from Tim Parkin:
Tests from Antora et.al and Heuer et.al:
Wow, Henning, thanks for that. A truckload of very interesting information indeed. I did save it in a file for future reference.
Frankly, I have some questions about the test method used for the resolution of the Nikon Coolscan 5000. I wonder e.g. if the test was performed with 16x oversampling and with 16bit per channel. The cleanliness of the lens element in the scanner should also be checked. I bought my scanner new in 2007 and when not in use it is always covered with a cloth + plastic bag. Tabletop scanners who are kept on the desktop for years do develop a layer of thin dust on the optical path which certainly degrades performance.
This test seems to be more in line with my experience:
browse down to "Image quality", the author arrives to a resolution of 4100 dpi (should be ppi) horizontal and 3650 vertical, averaging to a value of around 3900 ppi. That should be above 70 lp/mm and closer to 80 lp/mm.
In any case it is very interesting to see that the scanner is the weak link in this chain. Future desktop scanners might be able to extract even more details from our slides.
Henning, that Ektar comparison bothers me. I know that this film was designed to maximize sharpness and grain and the fact that it shows poorly in your example just does not match up with other information.
I know the filmscanner -info test. They used a printed higher contrast test target for their test, whereas we've used our real photos, our slides and negatives with the lower 1:4 object contrast testchart we have photographed. Our test therefore is much more relevant for real life shooting (that is always our aim).
Originally Posted by Diapositivo
With a higher object contrast, e.g. 1:16, you can surpass the 70 lp/mm with a Coolscan 5000, that is right. But the absolut physical limit is in 75 - 77 lp/mm range with this scanner.
But with a higher object contrast (in the subject you photograph) of maybe 1:16 you will also have a higher resolution in your original slide or negative. Then the resolution in our test would not be 120 clearly separated lines with the Zeiss and Nikon for example with Provia 100F, but 130 or higher.
So the huge resolution loss with the scanner is still there.
Don't waste your time waiting for better scanners for slides.
Originally Posted by Diapositivo
The method for highest performance with slides is already existent: Slide projection!
We've tested several projection lenses, e.g. the Leica Super-Colorplan P2, Zeiss P-Sonnar T and the Doctor-Optics / Kindermann MC-B.
With all three lenses we could transfer the 120 lp/mm of E100G, Elitechrome 100, Provia 100F, Sensia 100, Astia 100F onto the screen!
Same with 165 lp/mm of Agfa Copex Rapid as BW-Slide (developed in Scala reversal process)!
And even better: We projected a CMS 20 negative with 240-260 lp/mm and got 230 lp/mm transferred onto the screen!!
As now the recent tests with CMS 20 as BW slide have been successful, it is planned to do another test with the CMS 20 slide in projection. The resolution then will probably
even higher because of the higher contrast of CMS 20 slide compared to the CMS 20 negative.
For big enlargements slide projection delivers an unsurpassed quality. And at extremely low costs ( a projected slide on a 1m x 1,50m screen cost me less than a buck, a print of the same size cost me more than hundred bucks).