Exposing Tri-X

[Salvatore Formisano]

Hello.

I'm planning to shoot some Tri-X Pan 320 4x5 sheets and am wondering at which iso to shoot it. Is it best to shoot it at 320, faster, slower? or is it a matter of taste.

I've heard that for color print film you're best over exposing 1/3 stop since you'll get more color.

W/ BW, is there any advantage to shooting at a different ISO than rated (unless of course you want to push the film).

Thank you!

Sal

[Mark Sampson]

The curve shape of TXP-320, and long experience, suggest that exposing at EI 160 gives a better negative, with more shadow detail than one exposed at box speed. But EVERYONE'S experience, idea of a good negative, and opinion, is different; you'll find that out as more people respond to this thread. The best advice is to do your own exposure/development tests, and find for yourself what looks good. But I'd start those tests at EI 160.

[Richard M. Coda]

Testing... it's the only way.

My tests came out at 250 for "N" in HC-110 @ 75 deg.

[Filmnut]

Sal;
First, you will get many different answers on this one!
Basically, you have an enormous amount of flexibility on how you process your film with B&W. If you haven't already do some research on pushing(less exp and more dev) and pulling (more exp and less dev). Ansel Adams created the Zone system to be able to match the processing of the film to the scene, so that one can get the best and most consistent negs. It is rather involved, and even if you don't choose to actually go to the work of setting it up yourself, it is worth reading about.
There is a tremendous amount of info out there, on this forum and many others. Will you be doing the processing yourself, or will you be having a lab do it?
I have a few suggestions, but I am assuming that you have the basic knowledge of B&W film processing.
Much depends on what you want, and how you will print, or scan your negs when you've got an image that you like.
Tri-X is a fine film and has been favoured by many for years. It works well and is quite predictable.
To start with, expose a couple of sheets of an outdoor scene with a mix of subjects, a normal, that is set your meter to 320 then take a reading, and perhaps varying the exposure up or down a half stop. Process normal. If you're doing it yourself, use something like Kodak D-76, pay careful attention to temperature and time in the developer. To get some start times, you can do a search for the "massive developer chart", it contains processing info about many different films. If you're at lab, just ask them for normal for that film.
When dry, look at your negs. They should have a nice tonal range from highlights through to detail in the shadows.
Anyway, I hope that this helps. This is only the tip of the iceberg! There is lots more info!
Keith

[Capocheny]

Sal,

Take a look at the following FP4+ discussion:

http://www.largeformatphotography.info/forum/showthread.php?t=48403

Different films but similar principles/comments/suggestions. :)

Cheers

[Andrew O'Neill]

W/ BW, is there any advantage to shooting at a different ISO than rated

Yes. By using a lower ISO, you are sliding your shadows higher up on the curve, therefore giving them more luminosity.
You should do your own testing, because as you say, it's a matter of taste.

[Daniel_Buck]

I expose it at 320, but usually air on the side of a bit more exposure. That works for me.

[Skip Roessel]

I like EI 250 for average subjects, and err on the high side (more exposure, lower EI) when estimating the correction for bellows extension.
Skip

[Bruce Watson]

I'm planning to shoot some Tri-X Pan 320 4x5 sheets and am wondering at which iso to shoot it. Is it best to shoot it at 320, faster, slower? or is it a matter of taste.

For me it's a matter of testing. Do the Zone System tests to find your personal EI and your normal development times. This takes into account how you expose your film, your developer, and the way you process the film in said developer. Without doing the tests, you are just guessing. Why guess when you can know?

[Alan Curtis]

Buy a copy of Bruce Barlow's CD "Finely Focused: Mechanics and Creativity in Large Format Photography". It has a step by step procedure for film testing. Best $25 you can invest. It will save you time and effort in the long run and reward you with what you want, proper exposure and development.

[jason1388]

ISO 200 at all times for Tri-x 320 sheet film

[Stephen Benskin]

So many different answers and somehow they all seem to work. The speed of the film is the ISO. Your personal metering method and personal taste has a greater influence on how you will want to rate the film than the results from some additional testing procedure that generally has its own collection of flaws. My suggestion is to start with the ISO speed and see what works best for you. The real key is processing. This is where testing is most important. Be consistent with your processing and know what contrast you are processing to.