Dilution & times for TXP 320 (120) with HC-110?

[paul_viapiano]

I'd like to try this combo soon...but as I've read many times, the

Kodak times are way too short.

 

If I rate the film @ 320, what are the best dilutions and times to

use as a starting point?

 

(Kodak uses 4 3/4 minutes at 20C)

 

Thanks!

[lex_jenkins]

Yup, Dilution B is too short for comfort with tank processing of 35mm and rollfilm. Pour times become a time critical factor. It's better suited to tray processing.

 

Using Dilution H (1+63 or 1:63, depending on the source) allows extending the development time while getting the same results as Dilution B. Since it's half the strength I simply doubled the development time for my first rolls of Tri-X 400, 35mm and medium format. They turned out fine so I stuck with that.

[paul_viapiano]

The reason I ask is that I've read (on photo.net, I believe) that the real time for Tri-X 320 should be about 6-7 minutes.

 

So, if I use dilution H, would I double the 4 3/4 min Kodak time or double the 6 min that people say is the real time?

[amund_aaeng]

I use dilution B for 6 minutes, with the film exposed at EI200-250, works great, prints great on grade 3

[paul_hoyt]

Paul,

 

Here is a Photo.net link to my discussion on HC-110 and TXP 4X5 which should be very similar to 120.

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00DjlG&tag=

 

PH

[scott_eaton]

Lex,

 

Good thing HC-110 is pretty potent. At 1:64 any other developer would really loose speed with TXP320, which doesn't much to begin with.

 

I imagine the combo works pretty good though. Nice curve on TXP320. I found it a good compromise between TMY and TX classic.

[paul_viapiano]

Paul...

 

Your post on the TXP 4x5 is amazing!

 

Thanks for all that info. I know I should do the same thing with all the film I shoot to get my true speed, but that is a great starting point...many thanks!

 

I'm assuming that since you rate the film at ASA 250, that's why your N dev time is 9 minutes, and would be shorter if it were rated at the nominal ASA 320. Correct?

 

By the way, my final intention for the negs are for scanning, not darkroom printing. I'm not sure if that matters, though...

[paul_hoyt]

Paul,

 

Sorry, I have not been back to this thread until today and did not see your question. The difference between 320 & 250 is 1/3 of an f/stop. Sooooo No, the reason my time is close to 9 minutes is the dilution factor of HC-110. The approx normal time for Dilution B is 4 1/2 minutes (1+31), dilution H (1+63) has 1/2 the amount of HC-110 as Dilution B and takes approximately twice as long. I print all my negatives and do not scan, but I am under the impression development for scanning requires a softer (less developed) negative. There are posts in PN that discuss the difference in development times for people who primarily scan their negatives. If you have not already, try a search.

 

PH