Request an Acros-like film from Ilford?

[Steve Goldstein]

This thread prompted me to look at the spectral response curves of a few films (TMY2, FP4+ and Acros) for which I have datasheets. I was quite surprised to see that the curves for TMY2 and Acros are remarkably similar, with Acros a little less responsive in the green. Both seem to be flatter across the spectrum than FP4+. Acros and TMY2 drop off strongly in the red, at nearly the same wavelength, and both lose sensitivity more rapidly, i.e. over a smaller range of wavelengths, than FP4+.

Drew, have you ever compared TMY2 with Acros in the mountains? Given the similarity of their published curves, I wonder what the actual performance is. I would check it myself, but don't expect to be in high mountains again until the summer of 2014.

I also looked at the curves of the B+W 060 and Hoya X0 filters, both of which are yellow-green. They're quite similar at shorter wavelengths, but the X0 has notably less transmission in the orange-red part of the spectrum. I'll have to get my hands on an X0 to compare with my 060. That knowledge is certainly worth the price of a roll of FP4+ 120 from the freezer.

Thanks to all for the thought-provoking comments in this thread.

[Drew Wiley]

You need to look at curves closely. What might at first appear to be merely superficial differences can make a big difference in actual application, esp when it affects
the far end of the spectrum. That's why ACROS is officially classified as an orththopan film, while TMY is classified with pan, but with the disclosure over slightly lower
blue sensitivity than previous Kodak products. There are many other significant differences between these films. TMX responds so consistently to different primary
filters that it can be used as a color separation film for tricolor printing, at least until the behaviour gets messed up by undue recip failure. I don't have time to go into the very many tests I've personally done. As far as balancing the sensitivity, TMX will resemble ACROS with the addition of an XO filter, but let me get back
to this thread in a moment per mtn and high altitude use... gotta get something else done first .........

[Drew Wiley]

OK ... in the mtns or high desert you can often get very high contrast situations with a lot of blue in the shadows. I've successfully used all the popular films in such
circumstances but obviously have favorites. With ACROS you never want to use a red filter deeper than 25 or you'll just chop off a zone of shadows, whereas a 29
can be used with a typical pan film for slightly increased effect, though one has to be very careful about readings in the deepest shadows. And TMX will allow you to
dig deeper into shadows and get nice separation than either ACROS or FP4. These latter two films also seem to require a lower speed setting than box speed. ... I
rate both of them at 50, plus any filter factor. But TMX is very different and I rate it at 100, and you have to be careful not to blow out the highlights. ... in this
respect, pyro developers are a major asset with all these films. So yes, TMY will allow everything from deep shadow detail into sparkling snow in the same scene
without resorting to muddy minus or compensating development, BUT I gave up using it for such subjects because it has rather poor edge effect compared to the
other two films. ... might look sharp under a loupe, but less so in a print. Then per FP4 ... is a little more fragile than ACROS, not quite the linearity in high contrast
scenes, a tad less sharp, and of course needs more long exp correction.... and it's a normal pan sensitivity. Of course, one getting snow and rain and mist in the
mtns too, and not every shot is going to be high contrast. So you either take a versatile film or more than one. Wonderful prints can be made with any of these;
but I personally find ACROS to be the most versatile - a little more forgiving than TMX per exposure, and with that special luminous rendition of skies and foliage.

[Keith Tapscott.]

I recently emailed Ilford and asked if they had any plans to develop an Acros-like film, i.e. Delta 100 without the reciprocity issues.

Delta 100 already has very good reciprocity, but perhaps not quite as good as Acros.

http://www.willwilson.com/articles/0...ciprocity2.pdf

[StoneNYC]

Delta 100 already has very good reciprocity, but perhaps not quite as good as Acros.

http://www.willwilson.com/articles/0...ciprocity2.pdf

What are you talking about, deltas reciprocity failure starts at 1/2 second... Acros100 starts at 2 minutes! That's a huge difference...

[redrockcoulee]

I have a simple cure for those who find the cost of 4x5 ACROS prohibitive. Shoot 8x10 for awhile.

True 4X5 is less expensive than 8X10. With Acros in 120 format it is much less expensive than TMAX or Delta 100 however it is much more expensive than either of those when you go to 4X5. It actually goes from the cheapest of the 3 major brands to the the most expensive going from 120 to 4X5.

[Harley Goldman]

Delta 100 already has very good reciprocity, but perhaps not quite as good as Acros.

http://www.willwilson.com/articles/0...ciprocity2.pdf

The times listed in this article are far more forgiving (shorter) than any others I have come across. Keith, have you tested them and found them reasonably accurate?

[Drew Wiley]

Delta has a completely different personality than ACROS in several respects anyway - different curve (more toe), different spectral sensitivity. Speed and grain similar. As far as I know, there are no close contenders to ACROS in its long exp characteristics.