Pushing Tri-X three or more stops

[nina_t]

I heard that tri-x responds really well when pushed two stops, but I

was wondering if anybody tried pusing it three or more. My camera

has an option for up to ASA 6400, and I was wondering how I would

ever use it without pushing some film

thanks!

[arraga]

<p>Maybe this semi-old thread is useful

 

<p><a href=http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00DJ8w>Pushing Tri-X to 3200 in rodinal</a>

[silent1]

One data point -- Yesterday, I inadvertently exposed a sheet of TXT (old Tri-X Professional, ISO 320), at box speed, through the base -- that is, had it in the film holder backward. Previous reading suggests this would cost up to four or five stops, so I needed to do everything possible to the film to increase density (without going completely overboard with real exotica -- I avoided peroxide vapor, perborate, and latensification).

 

I mixed Dektol 1+9, added 5 g/L vitamin C powder and approximately equal amount of sodium carbonate (to counter the acidity of the vitamin C), then mixed in a quantity of HC-110 syrup as if making Dilution B. Developed 15 minutes at 70 F, with vigorous agitation every 30 seconds, and got a negative that looks as if it'll be printable (albeit with some fog -- this film is almost two years past expiration and has been stored at room temperature); only the deepest shadows are devoid of detail. By eye, I'd say I got at least one stop of true speed and a push equivalent to three stops, perhaps 3 1/2.

 

No idea how the grain will look, but with 9x12 cm, I don't have to enlarge much to make an 8x10.<div></div>

[arraga]

Hi Donald,

 

I believe tx400 has a different curve shape than txt320, with the later having a definite highlight shoulder much earlier than the non-pro version; maybe the pushing affects differently the highlight region in those two films.

 

BTW, congrats on saving your shot; i'd have hung my head in dispair.

[silent1]

I agree, Santiago, I think the "long toe" that's usually attributed to TXP/TXT may have saved this shot for me -- keeping separation well down into Zone I and even perhaps Zone 0 1/2, which would then become detail when the film was pushed beyond all reason.

 

Of course, now I'm going to have to try this soup again with sky images made with short exposures; if I'm really getting midtones at EI 3200 or higher, I might be able to record some decent star fields without having to leave the shutter open so long the stars turn into long arcs.

[nickr]

Donald,

How do you arrive at 4-5 stops through the base. A red 25a filter is pretty dark and is a 3

stop difference. I would expect 4-5 stops to be almost opaque to the naked eye. Unexposed

and developed base is not that dark. Base plus fully overexposed emulsion is, however,

pretty dark. Is this what you meant. (undeveloped emulsion is pretty dark also, but since it's

light sensitive from either direction it doesn't count). I'm sure I'm missing something simple.

[lex_jenkins]

Tri-X is easily pushable. It retains midtones well enough up to 6400 to make for good people photos.

 

Virtually any developer can handle it up to 800, even Ilfosol-S and Rodinal which are not good for pushing. Rodinal and D-76/ID-11 can even manage to scrape by up to 1600.

 

Ideal developers for 1600 are Diafine, Microphen, Acufine, HC-110 and a few others.

 

Beyond 1600 I'd use Microphen. Other folks report being satisfied with HC-110, Acufine, Xtol, Tmax and several others.

[silent1]

Nicholas, don't forget the antihalation layer -- this washes out in processing, but I recall someone mentioning a while back that a student, doing film testing, came up with a speed of 16 for TXT -- eventually traced to loading the film in the holders backward. EI 16 is 4 1/3 stops below the box rating of ISO 320. It *is* pretty nearly opaque to the eye...

[nickr]

Ah, that makes sense. Thanks for pointing that out.

[jim_appleyard]

I've had pretty good luck pushing Tri-X with Acufine. Dilute it 1+1 and it will get you and EI of 1000 if you dev. at 70F for 10 min.

 

EI 1600 for 14 min.

 

EI 3200 for 21 min.

 

I can't say about EI 6400.