TRI X at different speeds

Hi from Abu Dhabi!,
Can anyone tell me the reasons why one would want to shoot ASA400 film at say ASA125?
The reason I ask is that the only film I get get here is Tri X - and most of the time it's very bright & sunny - which would normally mean I shoot on a lower ASA - but 400 is all I can lay my hands on. So, are there any benefits to me downrating the film & will this effect dev time in ID11?
Thanks, Andy

Hi Andy,

See: http://www.digitaltruth.com/devchart.php?Film=Tri-X+400&Developer=&mdc=Search

Should help.

Roger

You could use a neutral density filter.

Some photographers notice a distinct improvement in their negatives when they downrate their film (or overexpose) and shorten development times just a wee bit. Shadow detail is improved (from overexposure) and highlights still hold detail (from shortening dev time). Especially in overly contrasty lighting conditions.

"a wee bit" being 10 to 20% depending on your downrating?

I shoot TX400 anyplace between 50 and 800, but mostly in the 100 to 200 area. It's a perfectly capable film rated anywhere in there.
And I don't necessarily adjust development accordingly as would be recommended. It all depends on the the light, the subject, your development, etc etc etc.

Most of all it depends on what you want the film to look like!

Exposure is a tool. Not a rule.

With that, if you want a good "normal negative" shot at 125, I'd probably reduce development by %20 for shade/overcast, and like %30 for sun. Just as a starting point.

I do not think one would like to shoot at any EI different than the correct one. The point is to know if the ISO recommended by the film manufacturer is your correct EI. I would try to explain a little bit more. TX400 is a 400 ISO film according with the Kodak technical department. It means that they get a density of 0,1 over the base film in Zone I when they develop with their laboratory conditions. In my case, I usually work with TX400 developed in 1:47 HC110, EI200. It means that, according with the way I develop the film (temperature, agitation, etc), I have to shoot this film with EI 200 in order to get a density of 0,1 over the film base when I shoot a grey card four steps less than the recommended by the light meter. As my method is, for sure, different from other people, my own EI will be different than the EI of any other photographer.
In other words, we should investigate which EI is the correct according with our own developing method, and this is the EI that we should work with.

Pat Erson said:

"a wee bit" being 10 to 20% depending on your downrating?

Click to expand...

Yes, "to taste". Meaning make a contact sheet and adjust for your meter/camera biases, the contrast of the scene, your water pH, and all those (sic) variable constants. Basically, idealized for your printing.

BTW: I shoot Tri-X 320 at 200 in the studio, but develop for Kodak's full term. I'm not recommending that, just saying it helps me make better prints.