Also think that even a superb lens kills most of the contrast at high cycles.
For film, MTF graphs are for an specific contrast ratio, this is not the same case than with lenses.
With film, depending on the contrast ratio grains of different sizes take action, so depending on contrast (and base exposure) the MTF graph is totally different.
In the 1000:1 contrast there is a 10 stops difference between lines, so in practice this can be made with a contact copy or perhaps with something like a semiconductor integrated circuit manufacturing lens (projection with reduction). By controlled fogging the film in advance (or after) you adjust contrast of the test and the base exposure of the (projected) black lines.
In that 1000:1 test, if black (projected) lines are in the toe (or not exposed) then white lines will be overexposed around +7, so you are to detect the effect of the ultra small grains having high resolving power over a "fog" from more sensitive crystals... 1000:1 does not describe the film behaviour in pictorial situations as you test crystals that are sensitive at +7 overexposure.
Instead a 1.61:1 tells the truth for common textures, 8:1 for contrasty edges, and 30:1 is good to guess performance for backlighted silhouettes.
If you see the TMX datasheet it says Modulation Transfer extintion at 200 lp/mm for TOC 1000:1 and 65lp/mm for TOC 1.61:1
The posted Provia graph is the one for the unobtanium 1000:1, clearly it has a tendence to extintion at 160lp/mm, well... commercially this MTF graph is nicer than the 1.61:1 would be.
I llustrated in green what it could be the 1.6:1 MTF graph, with extintion at 60lp/mm in that case.
With extended bellows and an extension ring or two (and stitching of course) I’d say I can hit 8000 dpi with my 24mp DSLR..8000ppi with a 24 MP FF DSLR as a scanner? No, definitely not. We've never seen such results. It is physically impossible, as the Nyquist frequency of these sensors is too low.
ADOX - Innovation in Analog Photography.
Current very good prime lenses transfer 60-80% of contrast at 40 cycl./mm. Excellent results.
This is total and utter nonsense that displays a complete lack of even the most basic comprehension of MTF and massive confusion with resolution testing. .
I shot film and scanned it for a little while and wasn't satisfied with the results. I now shoot digital and it is mostly black and white. You might want to give it a try.
Read ISO 6328:2000, try to understand it, and you won't say silly/ridiculous things.
Resolving power ≠ MTF. Do you understand that? MTF is the percentage of target contrast reproduction at a given resolution. The target contrasts are (and should be) controlled for. Do you understand this? MTF and RP have a relationship, but it is not the linearity you are erroneously assuming it is.
Well, for film it happens something similar, you have a MTF curve for each contrast.
For MTF measurement they use sinusoidal frequency patterns of varying density and contrast. The document doesn’t state which contrast ratios they test. But the MTF represented in the data sheet is normalized for the contrast range that their test procedure covers.
A true scholar has spoken.Anybody changed their mind in the last eleven pages of discussion because it sure looks like a merry-go-round to me. I shot film and scanned it for a little while and wasn't satisfied with the results. I now shoot digital and it is mostly black and white. You might want to give it a try.
Frank You have nice work on your site. Can you identify which were done in digital vs. film?Anybody changed their mind in the last eleven pages of discussion because it sure looks like a merry-go-round to me. I shot film and scanned it for a little while and wasn't satisfied with the results. I now shoot digital and it is mostly black and white. You might want to give it a try.
The document doesn’t state which contrast ratios they test. But the MTF represented in the data sheet is normalized for the contrast range that their test procedure covers.
I guess you will agree that depending on contrast the curve will be one or another...
The MTF represented in the datasheets is always the 1000:1 one, it always hits the rated TOC 1000:1 resolution at extintion.
See also where it has to hit the graph at 1.6:1 contrast: 50cy/mm in 0% (at extintion).
Also realize that the vertical scale is Logarithmic, so it results more nice, but see the 10% transfer horizontal how it cuts the curves:
View attachment 253798
This was TMY.
8000ppi with a 24 MP FF DSLR as a scanner? No, definitely not. We've never seen such results. It is physically impossible, as the Nyquist frequency of these sensors is too low.
The extinction resolution depends on the level of input contrast. The film MTF is only a description on how much of the input contrast is film recorded by the film. If we pick up your TMY MTF for a theoretical exercise and you start with 1000:1 contrast and the film has an MTF of 0.11% (extrapolated guess as Kodak does not provide data for this spatial frequency in the graph) at 200 lp/mm then the recorded contrast will be 1.1:1 and thus barely resolved detail. If your input contrast ratio is only 1.6:1 and the film MTF is 70% at 50 lp/mm then the recorded contrast on film will be also just about 1.1:1.I guess you will agree that depending on contrast the curve will be one or another...
The MTF represented in the datasheets is always the 1000:1 one, it always hits the rated TOC 1000:1 resolution at extintion.
At the risk of interrupting Lachlan and 138S (again),
The extinction resolution depends on the level of input contrast. The film MTF is only a description on how much of the input contrast is film recorded by the film. If we pick up your TMY MTF for a theoretical exercise and you start with 1000:1 contrast and the film has an MTF of 0.11% (extrapolated guess as Kodak does not provide data for this spatial frequency in the graph) at 200 lp/mm then the recorded contrast will be 1.1:1 and thus barely resolved detail. If your input contrast ratio is only 1.6:1 and the film MTF is 70% at 50 lp/mm then the recorded contrast on film will be also just about 1.1:1.
In practical photography it does not always work exactly like this as there are other factors to consider. The variably sized crystals reacting differently to light could be a factor. The MTF is only an approximation. Near a film’s resolution limit fine detail is rendered out of randomly distributed variable sized grain clumps and way too fuzzy to be accurately described by an MTF.
The MTF is only an approximation.
With extended bellows and an extension ring or two (and stitching of course) I’d say I can hit 8000 dpi with my 24mp DSLR..
I have never tested it rigorously though.
But I do get a clear view of the grain.
I can see why.OK, I won't answer Lachlan's anymore here.
Try it. But you certainly will not get your "8000 goal".
"But I do get a clear view of the grain".
But that does not mean at all that you get the full resolution. There is this myth on the internet, that when you can see the grain, you also have exploited full resolution.
But that is totally wrong.
Besides the fact that it is often more scanner noise or enhanced grain what you are seeing in scans, the max. resolution is a completely different animal:
We see that permanently in our test work: We can see clearly the film grain with a 20x grain focussing aid under the enlarger. But for evalution of the real, full resolution we have to use much higher enlargement factors: 100x under a microscope and slide projection.
ADOX - Innovation in Analog Photography.
Try it. But you certainly will not get your "8000 goal".
"But I do get a clear view of the grain".
But that does not mean at all that you get the full resolution. There is this myth on the internet, that when you can see the grain, you also have exploited full resolution.
But that is totally wrong.
Besides the fact that it is often more scanner noise or enhanced grain what you are seeing in scans, the max. resolution is a completely different animal:
We see that permanently in our test work: We can see clearly the film grain with a 20x grain focussing aid under the enlarger. But for evalution of the real, full resolution we have to use much higher enlargement factors: 100x under a microscope and slide projection.
ADOX - Innovation in Analog Photography.
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