Originally Posted by Jody_S
Interesting, what EI did you use for the imagesetting film ? Now that kind of film it can be bought at $8 per m2 , it can be a choice for ULF experimentation...
Interesting, what EI did you use for the imagesetting film ? Now that kind of film it can be bought at $8 per m2 , it can be a choice for ULF experimentation...
About 0.2? 3 stops lower than the lowest setting on my Pentax V. I bought 3 100ft x 12" rolls for $20 ea, IIRC.
thanks
Tech Pan is just that - designed for technical and forensic applications. I still have plenty of 8x10 for certain lab applications. I don't know what anyone sees in it for general use; but I tried it for that long ago, just like many people. There are way better pictorial options, esp for LF.
With TP you may get the "usual" LF image quality in a MF shot, and even a careful 35mm shot can be near as sharp as many 4x5" shots. Of course it also has drawbaks.
Adox CMS 20 is even more extreme than TP, but it can be used perfectly with a careful processing, I have several CMS 20 4x5" shots that are atonishingly detailed, YMMV if this is important or not.
Anyway CMS 20 sensitometry with POTA at ISO 6 allows a regular pictorial usage with not many limitations, you have 6 easily usable stops, 4 linear, so with accurate metering it is suitable for many scenes.
https://www.flickr.com/photos/53687643@N04/45541983072
Fine for a spy Minox copying a piece of paperwork decades ago, Pere. Might still be fun today for some. But for large format and even medium format general photography, many much more practical films have been engineered. Finer grain can be helpful; but for me, overall tonal response and detail acutance combined with realistic speed are factors a lot more important than sheer fineness of grain. Yes, a careful 35mm shot with a very selective film and exceptional lens can be nearly as sharp as a truly sloppy 4x5 shot taken with a grainy film and marginal quality lens; but that's not using the same set of scales. It was the marketing ruse Kodak employed for early Tech Pan ads in popular photo magazines, and had little relation to real world applications. I thumbed through some old 6x7 Tech Pan negs yesterday of a quite interesting scene, but quickly shuffled them back to the bottom of the stack simply due to the relatively disappointing printing qualities of Tech Pan. The day before, I encountered a Tech Pan 6X6 print of me in the mountains taken by a friend using a very high quality Zeiss lens, and who routinely shot Tech Pan for years, and knew all the relevant tricks. The lack of tonality in the extremes was highly evident as usual. Tech Pan was extended red, so could kinda wiggle into the threshold of infrared applications using a 29 filter, yet provided fine grain unlike true infrared films. That made it quite useful for certain forensic applications, but not really as a substitute for infrared films or the kind of ghostly look they provide of foliage.
That's the least of it - the high contrast resolution of a film matters if you are trying to image a 0.6m object on Earth from space, while the MTF performance and RMS Grain don't have significant impacts in that particular application, nor does the latitude need to be terribly great. On the other hand, for photography at ground level, high contrast resolution is irrelevant if the MTF is not good, nor the RMSG anywhere close to films near enough 3 stops faster. The fixation on high contrast resolution is a lazy, macho numbers game that willfully ignores almost the entirety of photographic science's approaches to understanding the ability of photographic emulsions to record and reproduce information since the early 1950's!
What size print do you want to make. Are you scanning?
B/w films generally have larger grain than color negative or positive at a given ISO. There are certain film/dev combos that this doesn't hold for. I've found that grain size and acutance are often at odds with each. With fine grain developers being low acutance, and high acutance being higher grain. There really isn't any winning with either option. Either your grain is super fine, but the image is soft when enlarged, or your edges are crisp, but the grain is larger. In my experience, the better option digitally is finer grain, then sharpen. In the darkroom, the higher acutance developers often enlarge farther since the grain is pleasant. Finer grain developers just get mushy if you enlarge them too far. Everyone gets too hung up on resolution, I can drum scan anything I want at 8000 ppi. Does that mean I can make a print from file at 300 ppi? Not necessarily. The limits of b/w film seem to be around a 12x enlargement, which means you need a 4800ppi scan. I usually use fp4, maybe bigger enlargements can be made from rpx 25 or cms 20. Though I would think that the lenses become the limiting factor.
For color slide film, there isn't much grain at all. Most the image is dye. The more you enlarge a slide, the softer I gets, though the grain shows up more. Sharpening really helps slides. Color negative film has noticable grain compared to slide, but finer grained vs b/w. Ektar 100 can be enlarged up to 16x before the grain becomes too large for my taste. Where e100 or provia just gets soft at this enlargement.
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Hmm ... I just start to notice Ektar grain at around 10X, up close, that is. At what point it might become apparent to a casual observer, I can't say. But 10X is my personal boundary of maximum enlargement. I would't go that big with any chrome film. It has nothing to do with the respective grain sizes, because we're really talking about distinctions in dye clouds rather than grain clustering per se like in black and white films. And given the fact chromes are inherently more contrasty, apples to apples subject contrast range wise, chromes therefore have more evident micro distinctions.
It will be interesting how my next round of internegs from old 4x5 of various chromes (Ekta 64, several generations of Provia and Velvia, plus Astia and previous Kodak E100G) - all contact printed onto Portra 160 (unsharp supplemental silver contrast included in most cases) - how they'll turn out in RA4 prints. Previous one enlarged onto 8x10 Portra, or 8x10 contacted to 8x10, responded wonderfully. In most, I avoided open sky subjects, but did do a couple of those. But my aim in only around 7X enlargement from these 4x5 contacts. Don't expect visible grain will be an issue. With the still bigger 8x10 ones, grain in undetectable even in 30X40 inch prints. The whole "grain" topic tends to get overblown in my opinion, at least in color film applications.
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