Drew, sorry for the reiteration, but this is a 4.5x5.5mm crop enlarged x60 in your monitor, from a 1885 5x7" plate (a wooden camera ?), a x60 of a 8x10" negative would have 15m.Originally Posted by Drew Wiley
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So to me it's wrong your statement that AA master could not make sharp negatives becuase of the era's gear. We may ask John Sexton, probably he could see several AA's negatives, I guess.
Nope. Wrong. You've got it backwards. Edge effects matter more in larger formats, in smaller formats, contrast substitutes for the edge effects as they bunch closer together. This is intentionally exploited in modern films.
Again, wrong. Those MTF charts are comparable, they are done by rather more complex analytical means than photographing a simple test chart on a wall - and the max resolution statements are irrelevant to the matter under discussion here. That you don't like the conclusions from the graphs is a different matter entirely.
All it tells us is that under conditions roughly equivalent to the flattest contrast a photographer might encounter, that was the best resolution they might get, not how grainy or sharp the film was.
And as for the glass plate: it's not difficult to take a neg from the 20's or 30's - or even the 1890's - & make a very big print from it & you'd think it was remarkably detailed. But if you then saw a print of similar enlargement from a similar negative format current production film alongside it, the difference would be really quite obvious.
Vaughn, I'm trimming everything I can. Put on a couple of inches of girth when I had to stop using a full pack for a couple of months getting over my shoulder bursitis. Did plenty of hiking, but not with enough weight. But I should have plenty of time to get back in full shape before the next serious backpack trip, at least to the extent someone my age can pretend to be in shape! Don't you just shed in summer like other furry creatures? My cats sure do. Gotta change out of my house clothes every time I walk into the lab lest I carry kitty hairs with me.
Pere - glass plates were still being coated for astronomical work up to maybe the 1980's, even in TMax 100 emulsion. Why? They're FLAT, dimensonally stable, and were made for use in massive extremely precise machines - nothing in common with garden variety old wood cameras and their often-warped holders with sagging sheet film in them, like AA used most of his career. But why am I wasting my time responding to you? You are 100% guessing about everything. I'm not. I've even duplicated and printed all kinds of antique photos, have a big collection of em. I've got a big pile of my brother's Super-XX negs in the room right behind me, as well as prints made from them. Please, please burn your calculator and your monitor, and maybe we can talk about actual photography.
Bummer about the bursitis -- my last bout of that was ten years ago. What cured it was helping out with my boys' little league practices -- gentle warm-up throwing (right shoulder). The easy repetitive movement was the key. YMMD. The same with my poor knees -- bicycle riding keeps the pain away. Actually hiking with a pack helps too, strange as that may be.
"Landscapes exist in the material world yet soar in the realms of the spirit..." Tsung Ping, 5th Century China
interneg, your statement is LOL. Even it's difficult to notice edge effects in 35mm film, with regular development.
Of course an stand agitation, with very diluted developer (1:1:400 pyrocat) and several hours of development may deliver edge effects with sheets, but this is not a capability of modern films, it's stand processing, "power of process".
I reiterate, the contrast level of the test is critical, TMX only resolves 40 lp/mm at low contrast, as the Foma graph has unknown contrast in the target we simply cannot compare. It is surprising you don't realize that
Well, just reduce the x60 enlargemet to x6, you will perfectly see that this 1885 image is perfectly suitable for that elargement level, still a 8x10 would deliver a pefectly sharp 1.5m print, or beyond. And that was in 1885, so it's LOL that 1940 AA negatives have to be blurred. Single AA blurred negatives are those taken with the crappy Adon zoom lens.
Look at the 4.5x5.5mm crop... it's obvious !!!
Last edited by Pere Casals; 2-Jul-2019 at 00:04. Reason: Spelling
Vaughn - Nothing cures my bursitis faster than swimming; but we won't be back in Maui for awhile, and am not keen on public swimming pools. The water was safer in the cattle ponds and creeks I swam in as a kid. One can get a steroid shot for bursitis that acts quickly, but allegedly that only works so many times, so I'd prefer to save it for emergencies. My stomach can't handle anti-inflammatories like Advil. Tylenol is OK. Last year I just went ahead and backpacked with bursitis. My clavicle could handle the weight. The real problem was driving there and back with my arm all cramped up against the truck door. That was misery. But nothing gives me old age aches and pains quite like some of these threads. Guess I'm addicted to them, at least until the evening news stops talking about politics; that's even worse. Some lovely PBS documentaries later in the evening, including one on the Amazon last night, beautifully filmed. B&W filmage of my Dad popped up in a PBS documentary a couple year ago about the Central Valley water wars, which began with the Friant-Kern Canal my father supervised. Had my ole art agent featured in another PBS documentary just a year ago. But when the self-help guru programs go on, I wanna throw a boot at the TV. I grab a book, a cat jumps on my lap, and try to get some calm before my wife wakes up from her evening nap (hectic medical career).
Sharpness in 35mm is more reliant on contrast from the higher density inherent to finer line resolution behaviour & in LF by edge sharpness. Thus getting 50% MTF response or better at as high resolution as possible matters more for smaller formats, getting a 100%+ response in the 10-20 lp/mm will strengthen edge effects for larger formats. Older films exploited this much more poorly or not at all. Thus they are less perceptibly crisp when enlarged to a big size. And that's before considering interimage effects, antihalation etc.
All you're showing is you can't read an MTF test to save yourself. It's not about the other resolution specifications that don't relate to perceptible sharpness. If properly performed, MTF tests should be usefully comparable.I reiterate, the contrast level of the test is critical, TMX only resolves 40 lp/mm at low contrast, as the Foma graph has unknown contrast in the target we simply cannot compare. It is surprising you don't realize that
Just to prove that you're reading the graphs, tell us at what lp/mm TMax 400 drops below 100% response & where it delivers 50%. Then do the same for Fomapan 400. Those numbers tell us much more about the relative sharpness changes over the decades. The difference between these two and the single run emulsions of the 50's and earlier is just as dramatic. The old emulsions are not unsharp, or particularly poor resolving, but compared to the materials that came after they do not have the same intensity of sharpness or finer, more sensitive grain structures.
As Drew said, you are in desperate need of gaining actual experience with the materials you spend so much time & urgency telling us about.
Nope. Beyond properly performed, contrast of the target has to match in the tests you compare, it's surprising that you don't realize that.
In the TMX MTF for the 1000:1 contrast I add the MTF for a low contrast target, datasheet (page 25) says that with 1:1.6 contrast target you have extintion by 40lp/mm, so the rest can be interpolated.
You should realize that 1000:1 contrast is 10 stops, in practice you will never find that contrast on film because the lens is not able to deliver say 40 line pairs per mm with the white lines 10 stops brighter than the black lines, such a contrast in fine detail is not feasible by far, only a silhouette in a insane backlight may deliver 10 stops contrast, but the lens may deliver 1:2 contrast at 30lp/mm in most cases. Fine textures are usually more close to 1.6:1 contrast on film.
Interneg, you should be aware of it...
TMX (and TMY) has layer of very small cubic grains under the main emulsion that works in the extreme highlights to deliver a linear response there.
At 1000:1 contrast you mainly evaluate that layer rather than the main emulsion. Kodak datasheets are very good (says TOC 1.6:1 and TOC 1000:1), but in this case that graph is a bit missleading because performance in the 1000:1 contrast has little importance as usually is not found in pictorial work textures. For a photographer with technical curiosity a (say) 1:4 contrast MTF graph is what it would be useful.
Last edited by Pere Casals; 3-Jul-2019 at 04:25.
Lots to mull over. Not only flare but larger prints need different contrast than small prints to look good.
So I just “proof” on 11x14. If it looks good I don’t have to figure out what to adjust for the final print...
Because the final print is in my hands.
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