Film granularity/LPM chart
I put this together for my own edification and reference.
I believe in trying to get objective information whenever I can in life. Such info may not be the whole story, but it's a good place to start. I don't put much stock in individual's observations, so many variables and skill sets are in play, to say nothing of meaningless descriptors.
Ilford does not release this type of information, although I found RMS granularity for the FP4+ movie film.
If Fuji is to believed, they have the best films for a given speed bar none. For any given film speed, they claim quality equal to everyone else's one speed lower. Frankly, I don't believe that they alone hold great film making secrets. In fact, I garnered enough information on the Acros rating to see that they used a proprietary developer - probably never seen on these shores - and then rounded down.
I read recently that engineering types say Lines per millimeter (l/mm or lpmm) whereas photographer types say Line Pairs per millimeter (lp/mm or lppmm).
However, when engineering types say lines per millimeter, they usually mean line pairs per millimeter so 60lpmm = 120 lines.
Confused? Well I am because you never know what the quoted numbers actually mean if the don't say lppmm. Do they mean 60lpmm or 60lppmm?
Good job, Paul. It is hard to boil it down to a spreadsheet.
EKC is correct and forthcoming, giving you the criteria for granularity tests,
they use normal developers, and not always the ones which will give the highest numbers but ones which will likely be used in normal practice. Finally, they define the contrast level for their resolution values.
Look at the Neopan 400 data. Where, exactly, was that from ? Fuji does not have that information on their data sheets.
Equal granularity, and similar resolution to TMY ? Right.
As for Acros, Fuji's data rightfully equates it to TMX; it is noteworthy that EKC got their numbers from D-76, Fuji from their Microdol X equiv. As you point out: anything to get less granularity than Kodak.
The tradition is to publish the source of the data. Without manufacturers' help it is an impossible task. The best thing to do with scanty data is to not split hairs over unsourced data, Acros & TMX being a good example. Especially if you are going to use a different developer than produced the data.
Curve shape and color sensitivity are more important to the image anyhow. Good job.
Apples to apples
As long as they are all using the same standard and technique, the precise definition and terminology doesn't matter. And I do believe that they are. It's old, established science.
Originally Posted by rob champagne
Cardwell; good observations, all so true. I believe that I found the Fuji info on the film data sheets. I believe the inferences about Fuji "cheating" was found somewhere on the net. Since this was for my own use, I didn't keep everything footnoted. But, hey, trust me!
Good points on Kodak using real world developers. There's only one reason anyone would use a strong solvent developer on a slow T-grain film and that is to fudge the specs. No one in their right mind would do it in the real photo world. It wouldn't surpise me that the used a different developer (dilute D-76?) for the sharpness determination.
Looking at the now deceased APX films, one can only pine for their best of both worlds ratings. Unlike Fuji, their ratings are more believable, I think.
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Let's add something to this...
Page 11 and 14 show data.
I have some german documents. Sorry...
A while ago, I found a document by Zeiss, listing the fims that they use for testing lenses, from 2003:
Since 1999 they use Fuji Velvia as a reference and confirm 160 LPM, which is what Fuji says.
In Black-and-White they stocked up with Agfa APX 25 before its production ended. They confirm 200 LPM, which is what Agfa said.
In the meanwhile they must have switched to a new film: Spur Orthopan.
SPUR Orthopan UR, resolution 400+, higher than Kodak Imagelink HQ with 320 LPM. They say that 400 LPM is the absolute limit of any lens at aperture 4, a final frontier caused by diffraction.
Efke 25 has 115 lpm
ROLLEI INFRARED IR400: RMS 11, 160 lpm
Rollei ATP: 300 lpm
cmo, great research and thanks for the info! I'm going to add it to my chart.
Maybe it is a good idea to ask the manufacturers, too? They must be interested in objective information...well, as long as they are not from China and as long as we don't raise an issue like doping
After that, why not make a permanent link here and publish it on sites like digitaltruth.com?
All but a few of the specs I listed came from manuafacturer's info sheets. A few were second generation, I presume they found something once upon a time somewhere.
Originally Posted by cmo
Ilford, as noted, refuses to supply such info. I understand, and yet I don't. I'm sure that they have nothing to be ashamed of, and most people accessing this type of information understand that it's only a starting point.
My dream is a database of all films, showing a standardized example, the film exposed and developed according to the manufacturers' manuals, scanned in a standardized way on a high-end drum scanner and showing small crops of the images on a website. To make it really complex, varieties of the setup using other developers are a must :-) So, everyone could get a good impression instead of listening to repeated advertising BS... but it's the work of a lifetime.
Originally Posted by Paul Verizzo