Techpan EI rating/Processing : LUSENET : B&W Photo - Film & Processing : One Thread

What ISO ratings are people setting Techpan at? How much can you push this film without affecting it's grain. I am interested in stepping it up from ISO 25 but i am interested how much, and with what developer?

Thank you


-- john molloy (, September 28, 1999



You really don't have too many choices without receiving some sort of dramatic effect. Most "normal" developers may yield the additional film speed that you are looking for but not without a significant gain in contrast. Tech Pan is a rather unique emulsion that requires a softer working developer in order to render a contrast range (CI) that falls within a usually desired range. Also, Tech Pan is not really a film that lends itself well to pushing. I have managed to obtain film speeds as high as EI 32-40 with higher dilutions of XTOL and longer processing times, but there is very little benefit in doing so--if any. If it's speed that you are looking for, I would look more towards a film like T-Max 100. I hope that helps.

Michael D. D'Avignon

-- Michael D. D'Avignon (, September 29, 1999.

I've recently been experimenting with Ethol TEC for TP, but at 1:15 rather than the recommended 1:30. 5'30"/70F for EI 50 looks promising.

-- John Hicks / John's Camera Shop (, September 29, 1999.


My best results with Tech Pan have been with Photographer's Formulary TD-3. You can get an extra stop of speed with no apparent increase in grain. It's the only developer I will use for this emulsion. Contrast is variable through dilution.

My $ .02

-- Walter Massa (, September 29, 1999.

I've had good results at EI 32 with Microphen diluted 1+5 for 14 min. @ 75 deg. F.

-- Tim Brown (, September 29, 1999.

Go download Kodak's Technical Publication #255. It has exposure indeces and contrast indeces for various developers. You pay dearly for increased speed in the form of increased contrast. Most people around here agree that shooting at an EI of 50 and processing in TD3 is about the best you can do.

-- Fritz M. Brown (, September 29, 1999.

I rate Tech-pan 25/100, develope in Kodak's SD-1 Pyro. Pat

-- pat j. krentz (, October 01, 1999.

I'm souping tech pan in diafine at an E. I of 80. Results are better than technidol and ethol TEC, with little increase in grain size. Rodinal is usable at 100:1 but at an E.I. of 12. The negatives from diafine seem to have a broader range of tones. The trick is to soup in the "b" solution for exactly 60 seconds to get a "2" contrast. The longer times in the "B" solution build contrast. Other wise, time in the "A" solution (3-5 minutes), temperature( 70 -85 F ) and agitation (once a minute) have little effect.

It also works wonders on T-max as all development variables are eliminated!!!

I recently thrown out d-76, ethol TEC, T-max, Rodinal and microdol developers and am learning not to worry about film development as a variable in my work.

-- Gene Crumpler (, October 01, 1999.

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