Best way to get ASA 640 out of Tri-X

[jonathan1]

Photo life is much better for me when I can shoot at 640 than when I must shoot at 320. All my black and white shooting, for the time, being is on Tri-X. Now, Kodak says on their website that a one stop increase in Tri-X's speed is best accomplished by processing normally, and falling back on the emulsion's exposure latitude. Other sources, however, insist on pushing, or substituting microphen or accufine for one's normal developer. What's a poor novice to do?

 

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FWIW, I have been following the oft-given advice to stick with one developer (FG7, no sulfite) until one has a feel for its potential. I've gotten my time/agitation down to a point where I like the negatives I get from Tri-X at 320 and FG7. So, what's the best way to

get negs processed at 640 that (as closely as possible) resemble the negs shot at 320?

[john_lehman2]

It depends on the contrast of the scenes which you are shooting.

If contrast is less than "normal" (e.g. less than 8 stops from

darkest gray to lightest textured white), you can shoot at 640

and extend development time by 10-15% and the results will be about

like what you get at 320 with normal development. If you are

shooting high contrast scenes (like night-time available light),

extending development or switching to something like Acufine will

increase the contrast at the same time it builds up shadow detail.

Developing normally will lose detail in the darker areas. There is,

unfortunately, no way to "push" film without increasing the contrast

(altho you will probably get lots of advice that using magic developer

"X" will do so).

[john_hicks]

Use Microphen or Acufine; you'll get EI 500-640 with a "normal" CI.

 

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No matter what Kodak says, film that's a stop underexposed and given normal development is still a stop underexposed.

[tim_brown9]

I've had excellent results using Microphen. I dilute it 1+2 and worked

out my own dev. times. To me, Acufine seems to give grainier results.

[lot_wxs]

Microphen or the Kodak advice on the film's latitude. The latter maybe

more often more adequate than you think, especially when you print on

VC paper with split contrast printing. If you use a lens which has a

good performance at 2.8 you'll be amazed how much is possible with

2.8/4.0 with 1/50.

[lot_wxs]

Oh, I use HC110 for the latitude method. I agree with some here that

Acufine give muddy grain, Diafine is better.