Hp5 vs TMY400

[interneg]

Well, we cannot say that HP5 speed point (3.3 stops underexposure from box speed, at red lines) is completely outside the toe, but it's clearly in the good detail zone yet, in fact much better than (rolls) TX400...

Attachment 175298

Without knowing what developer, dilution, temperature or agitation regime these curves represent, there are very few conclusions that can be drawn from them, other than that the TX curve is lumpy enough to doubt the quality of the work that went into plotting it.

[Drew Wiley]

I don't have any experience with Xtol, but under-dev with D76 and its clones will yield enough sag in the TMax curve to superficially resemble several Ilford films. But that's like saying you can drive around with only 15 lbs of tire pressure. Yes you can, but ....

[Michael R]

It's always interesting to see how many incorrect things Drew can fit into each post.

[Drew Wiley]

Dream on. People who have actually done their homework have come to the same conclusions, and right from Day One, Kodak published a family of curves of D76 VERSUS what they recommended in order to get the most out of these films.

[Michael R]

Nice try, but again, totally incorrect.

[Drew Wiley]

Ho hum. I got multiple binders of utterly predictable densitometers plots on TMax under a whole suite of variables. As I mentioned earlier, it was designed to replace certain commercial or industrial film, and not just pictorial or photo studio. More TMY sheet film still probably goes to technical or industrial use. Certain specialty labs stake their whole process standardization on known characteristics which you've probably never thought of, Michael.

[Ken Lee]

Does this help ? From the Win Plotter collection of BTZS film tests: Kodak TMY in D-76

Is this evidence of a sag with shorter development ? They all look pretty linear to me.

I'm no expert.

[Drew Wiley]

Yes, that looks quite characteristic of D76. Certain people, esp Ctein and myself wanted to straighten out the extreme low-contrast sweep which plagued Pan Masking film, while finding a suitable replacement once that specialty film was discontinued. The progressive upsweep in D76 with TMX or FP4 was actually useful in Cuba printing, but a liability in Dye Transfer, and sheer voodoo in color neg masking, which needs to be much more subtle. He published his Muir Softshot formula, and considerably later, I came up with a special tweak of HC-110. Both use toe-cutters. Initially, Kodak recommended HC110 B for the best linearity at normal to high contrast, but then came out with TMRS. The main problem with it is the 75° temp necessary for optimum results, which can lead to edge frilling. It's also expensive to use. But at double-strength, one-shot 75F, TMax launches straight off the toe like a rocket. But for pictorial or portrait use, I greatly prefer the printing control of pyro stain.

[Pere Casals]

Likely to do with the different toes of both films - TMY-II has a shorter toe than HP5+ & if you want to get definitively off the toe and on to the straight line section, that's going to affect your EI.

Better for portraiture? Well, in my system TMY is twice as fast as HP5+. That allows using a smaller aperture or a faster shutter speed. Both can be important for portraiture.

IMHO you are right in that toe is different, and this may lead to a different (longer HP5) exposure if wanting full contrast and detail in the 3 stops underexposed areas.

Per definition of ISO Speed we have exactly 3.3 stops underexposure latitude, to the speed point, at left of it we just have a 0.1D range, also per definition of Speed point.

So, at the end, what's the difference ? with N development IMHO HP5 at -3.3 stops still has not reached the full linearity and it's still compressing a bit the shadows, but by -2.5 stops it's clearly in the linear side.

But this is not good or bad, at the end we have a 2.0D static contrast limit in the print or the monitor, while the scene normally has more range, normally we have to compress shadows and highlights to allow enough range for the mids and the volumes, so anyway we are to compress shadows in the print, if we don't do it in the negative we are to do it in the print.

We have to remember that Karsh was doing extensive usage of toe compression of the shadows, IMHO he was making accurate shadow metering to compress, then had more freedom with graded papers.

What I say is that it's irrelevant if a film has toe or not, what's relevant is if one is Karsh or not. A good portrait comes from a good photographer and from mastering the medium and gear one uses.

HP5 and TMY are very different films for small format because grain, for LF we have slightly different toe and some different filtering for the same result, but IMHO a portrait photographer won't obtain better or worse results because that, but because him.

[Pere Casals]

About the shadow compression I'd like to point something else.

IMHO result is equivalent if deep shadows are compressed in the film toe or in the print shoulder, if we want a "contrast increase" in the shadows we'll need to use selective additional tools anyway, one is scim, another is split grade printing/dodging/burning.

I guess that stain developers have an effect there, because with VC papers the stain color also works as a selective contrast filter depending on density...