Platinum Printing and ? changes in T-Max 100

[scott jones]

Greetings,

A large format photographer freind of mine who does not frequent the internet boards is having trouble and I thought I would querry my friends here. He has used T-Max 100 4x5 film forever in doing platinum contact printing. Recently he has not been able to print with new negatives of recent boxes of T-Max but old negatives print just fine, so he knows his process is OK.

Has anyone had similar experience and does anyone know if there has been a change to T-Max 100 that would possibly make platinum printing not work (such as some new anti-UV companant to the film etc.)

Scott

[Jorge Gasteazoro]

I use Tmax 400 in 8x10 and the new film works just as well, albeit a little less developing time is required. Kodak adviced of this new change and most likely your friend is blowing his highlights, specially if he is using a stainning developer. Without knowing the details of your friend's problem is hard to give you any "good" advice.

[scott jones]

I may not have made myself clear. It is the Printing that he is having problems with. The negatives look fine, but the UV exposure is not resulting in a print, while the same printing technique done with older T-max 100 negatives are still printing fine. Weird eh?

Scott

[Jorge Gasteazoro]

Sure is, unless he is developing for negs that are too dense......Other than that, the new Tmax works for me...so I dont know what to tell you.

[clay harmon]

This is the first in-the-field confirmation I have heard of this. I sent Sandy King some pyrocat HD film tests on various films about 6 months ago so that he could run them on his UV densitometer. He noticed that the UV wavelength b+f for TMAX 100 was 1.0 as compared to .15-.3 for most other films! That is a full two stop difference. Kodak must have some new film base that blocks UV.

I normally don't use TMX, so I never got around to seeing if this actually had an effect on my platinum printing. This makes me nervous about the 10 new boxes of 12x20 Tri-X I just got from Kodak! I HOPE they did not make some change to the film base for their other films. I'm going to run some tests right away and I'll report back.

[sanking]

I can confirm Clay's report, and also note that a second batch of new TMAX 100 film, of very recent manufacturer, tested just a few days ago also, also had a very high b+f reading (over log 1.0) when reading in UV mode with my densitometer, which reads in a narrow band around 373nm. I would be suspicious that all TMAX 100 film of recent origin has the same UV blocking filtration. Since I have not actually tested TMAX 100 with printing using UV radiation it was not clear to me that the UV coating had any impact on printing with Pt/Pd and I posted a note on the alt-photo-process list last to see if anyone else had noticed an increase in printing time with new TMAX 100 film. It would appear from the initiation of this thread that the UV coating may indeed have some impact on actual printing times, though I can not personally verify this at the moment.

BTW, I stripped the emulsion from the TMAX 100 film and verified that the UV blocker is in the coating, not the polyester base.

The latest TRIX-X 320 film and TMAX 400 that I have tested do not block UV light so people with large custom orders of these films will hopefully not be inconvenienced.

[David G. Gagnon]

Just to clarify, didn't Kodak in their infinite wisdom label the NEW film "100 Tmax", while the OLD film was "Tmax 100". It might be helpful to use those names to keep the old and new films straight.

Just my two cents.

DG

[scott jones]

Good point. We are talking the new 100 T-Max here. Thanks...

[sanking]

Yes, interesting point about the name change. But what is the official designation of 100 T-Max. I believe it was TMX, right? Does that designation continue with the new film?

On a follow up to my question to the alt-photo-process list I had a response this past evening to my comment about UV blockers in the new 100 T-Max film from Dr. Bruce E. Kahn, a scientist in the Imaging and Photographic Technology department of the Rochester Institute of Technology. He writes

"Sandy, you are correct that T-Max appears to have a UV absorber in it.

I am currently teaching a course on 19th Century photographic process. A graduate student noticed some interesting differences between different negatives (T-Max and Ilford FP-4). I did some quick absorbance measurements for some of the materials that students were printing using a spectrophotometer. I have posted some of this data at <http://www.rit.edu/~bekpph/historic/films.jpg>. As you can see, T-Max absorbs UV from ~ 320-410 nm. There is a fairly narrow UV transmission window at about 320 nm."

After looking at Dr. Kahn's data it would appear to me that the UV blockage in 100 T-Max film would be very significant for UV sources such as BL and BLB tubes that put out most of their radiation below 420nm, and also consideable for platemakers such as the NuArc 26-IK, both Mercury and Metal Halide lamps. On the other hand, sources such as the Super Actinic or Aqua, that radiate primarily above 420nm, might not be much impacted by the UV blocker in T-Max.

[Sal Santamaura]

Two points. First, Jorge is using Professional T-MAX 400/400TMY, while most of the other discussion and anecdotes specifically refer to Professional T-MAX 100/100 TMX. Dr. Kahn's response does not identify which T-MAX film his data refer to, but, in light of Sandy's question, it's probably also the new 100 TMX. Since Kodak claims that 400 TMY has been made in its new facility for quite some time, and was not recently changed, perhaps a UV absorber was only added to 100 TMX during the move.

A second, though off-topic, point of interest is that 100 TMX's UV blockage might prove useful in enlarging. The focus shift that Ctein documented (resulting from enlarging lenses' failure to focus UV and visible rays at the same plane combined with VC papers' sensitivity to UV) might be mitigated when printing from 100 TMX originals. I haven't printed any, but would be intersted to hear about this possibility from those who have.

[Philippe Gauthier]

Fascinating... and frightening. I hope that all manufacturers won't make an habit of adding anti-UV coatings to their procuct.

Sandy mentionned that most film tested between 0.15 and 0.30 As most of us don't have the quipement to measure UV transmitivity, would it be possible to post the results for the films taht have been tested? Information about classic films like FP4+ HP5+ and Tri-X would certainly be appreciated by a lot of people here.

[Mark_3632]

Here is probably a dense question but what benefit is there to putting an anti UV coating on in the first place?

[Jorge Gasteazoro]

Philippe, I only use 400 Tmy and FP4 so my measurement for b+f are .21 for FP4 and .19 for 400 TMY. Note though that for an SBR of 5 or what would be N+2 in zone system the b+f jumps to .30 and .25 respectively.

[sanking]

Philippe,

The b+f UV readings vary a lot with films, with the developer, and with the CI to which the film is developed. For example, with FP4+ the b+f UV reading is only about 0.08 for a CI of 0.55, but it jumps to about 0.25 for a CI of 0.85. TMAX 400, TMAX 400, and most of the Hungarian films (BPF, JandC, Forte, etc.) will have a UV b+f of over 0.15 with a CI of 0.55, which will increase to over 0.50 for a CI of 0.85. Ilford HP5+ has slightly lower b+f UV readings than the Kodak high speed films.

The above is with develoment in Pyrocat-HD, a staining developer. Other staining developers will give different results.

[Philippe Gauthier]

Jorge Sandy: thank you for uncovering this little known piece of lore. I suppose that the data would be pretty different with a non-staining developer, especially with the Hungarian films which are known to stain well because of their thick emulsion. My current choice (HP5+ in HC-110 dil B) is probably pretty UV friendly, which is exactly what I needed to know.