TMax 100 and UV Blocking

[Tom Westbrook]

I saw that, too. I did see on APUG that one preson found a 3 stop factor vs. a 'normal' film. See http://www.apug.org/forums/archive/t-6540.html

There's also a reference to the "alternative mailing list" that might have more info.

[clay harmon]

I have a UV densitometer and I can confirm that the UV base+fog of Tmax 100 is about l.1 logD, as compared to .15 for Tri-X and Fp-4. This is possibly the worst film EVER made for alternative UV light sensitive processes.

[Mike H.]

Some locals using platinum/paladium were advised that there is a solution to the problem and have used it successfully. It just requires soaking the negatives after development for a period of time (a minute or two) in some solution - alcohol based? My apologies for not knowing the actual solution, I just know that they solved the problem. Maybe you can check back with the Kodak people and ask them what you do to remove the coating - or someone here in the Phoenix area that has used it will reply with the answer.

[Mike H.]

Just checked with my local contact who does that stuff (a retired neurosurgeon). Anyway, uses normal 70% rubbing alcohol. Soaks negatives in water for 5 minutes (this is after they've already been completely developed and dried), then the rubbing alcohol for 5 minutes, then rinses in water for 10 minutes. You need to aggitate when in the alcohol, but not when soaking in the water. Them's the directions. Hmmm.. another 20 minutes of work. That will probably drive some folks to alternative films for the alternative printing...

[jim Ryder]

Help me with this, because I have been getting beautiful plat/pal prints using both old and new TMax 100. When I do my film tests it is zeroing on the film plus "film base plus fog". So I assume in exposing the film this is not a factor. In printing the film whether using an artificial or natural sunlight (which I use) because the film base will be even the only affect will be an increase in exposure time. Is there something special about that part of the spectrum that I am missing. I am not the most careful worker and am very far from a sensitometrist(?) my only goal is to get beautiful prints so perhaps my experience should be discounted. I love tmax 100 and bostick and sullivan plat/pal coatings.

Thanks.

[sanking]

"Help me with this, because I have been getting beautiful plat/pal prints using both old and new TMax 100. When I do my film tests it is zeroing on the film plus film base plus fog."

No one said that Tmax 100 could not be used to print Pt./Pd., but unless you remove the UV coating printing will be about three stops slower than with other films. In other words, an exposure of 4 minutes with FP4+ would become an exposure of 32 minutes with Tmax-100. If the longer printing times UV sensitive processes are not a problem then there is no reason to not use the film.

BTW, how long are your typical exposures in sun? And are you printing in direct sun or in the shade?

[jim Ryder]

Thanks, that's what I thought, I just wanted to make sure I wasn't missing something. I only use direct sun as that is the only way I have to control intensity. My exposures vary from 3 minutes to seven minutes. I like that time range, makes me feel I have a subjective, intuitive control. I look at my watch and say, "That's about right"....and maybe wait a few seconds more. My negatives typically are very dense and my images are very dark. A richly constricted range of tones, I try to strip the light out, and work in pure volume, form and line.

[Joe Smigiel]

Yesterday I ran an exposure test with TMAX films using a Nu-Arc 26-1K mercury plate burner. My normal exposure for double-coated Van Dyke Brownprint on Cranes Kid Finish and an HP5+ negative is around 400 units of exposure. I gave the this test 500 units which took 29 minutes.

For the test I attached a Stouffer wedge to a sheet of new TMAX 100, another to a sheet of old TMAX 400, and another test wedge in direct contact with the paper (i.e., no film in the UV path). The visible FB-F as measured on a transmission densitometer was 0.02 for both films, neither of which had been developed, only fixed and cleared.

My results indicate the new film is blocking 4 steps or ~2 stops exposure at this level of 500 units total exposure. To compensate for this, the 500 unit exposure would need to be extended to 2000 units and that would take nearly 2 hours to expose.

http://my.net-link.net/~jsmigiel/images/technical/VDB_TMAX.jpg

[Joe Smigiel]

Today I tried the isopropyl soak for 5 minutes without gaining anything. For today's test I reduced the overall UV exposure to 400 units which is where I usually print HP5+ negatives on Cranes' paper for VDB. I included a zone system test sheet run on HP5+ along with the sheet of old TMAX 400 and new TMAX 100 (half of which received the alcohol treatment.) I note that the HP5+ negative had a FBF density of 0.18 vs. the two TMAX films which registered identical FBF values of 0.03 or one-half stop less visible density than the Ilford film. Yet, the HP5+ negative printed out a full stop beyond old TMY and 2 stops beyond new TMX after processing and drydown. (The image at the URL below displays a full sheet of paper with the three negatives exposed together for 400 units on the Nu-Arc.)

http://my.net-link.net/~jsmigiel/images/technical/TMX_TMY_HP5.jpg"

[Sal Santamaura]

"This is possibly the worst film EVER made for alternative UV light sensitive processes."

Perhaps, but it also might be the best film ever made for printing on modern VC papers using UV-rich enlarger light sources. Perhaps that's why Kodak added the filtering?