Flexibility of pushed Tri-X

This weekend I'll be shooting a fair bit of Tri-X in mixed conditions - indoors/outdoors/daytime/nightime. Hand held with reasonably fast shutter speeds.
In these instances I'd normally shoot it at 1600ISO, with the lab pushing two stops in dev.

However, I wondered if there's any benefit at shooting some shots at 800ISO when the light allows on the same roll if I want a less contrasty shot or more details in the shadows ?
Ie There would be a mixture of shots at 800 and 1600ISO on the same roll, with the lab doing a two stop push in dev.

Contrast is determined by development, not by exposure. When you mix 800 iso and 1600 iso shots on one film and develop the film as 1600 iso all shots will be developed to the same contast. The 800 iso will have better shadow detail of course. The only way to make this work is use two camera's: one loaded with 800 iso where you want more shadow detail and less contrast and the other for 1600 iso film, or shoot a complete film as 800 iso and the next one on 1600 iso. Mark the film accordingly and have them developed seperately.

Although it has mixed views on this site, you could shoot at both speeds and then 'stand develop' the film.

Terry S

Huub said:

Contrast is determined by development, not by exposure. When you mix 800 iso and 1600 iso shots on one film and develop the film as 1600 iso all shots will be developed to the same contast. The 800 iso will have better shadow detail of course. The only way to make this work is use two camera's: one loaded with 800 iso where you want more shadow detail and less contrast and the other for 1600 iso film, or shoot a complete film as 800 iso and the next one on 1600 iso. Mark the film accordingly and have them developed seperately.

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I'll venture this thought: while Huub is technically correct, the latitude of the film should be able to handle 800 and 1600 on the same roll; I'd split the difference and process it as 1200. They may not be the most perfect negs you've ever shot, but pushing film a stop or two is already moving you from "perfection" as far as shadow detail. Is it an optimal way to shoot? Maybe not, but if you have (or only want to carry) one camera, it can be the difference between getting a shot or not. I'd stop thinking of it as "pushing" and more of "the shutter speed/aperture combo I require for this photo means it'll be an extra stop underexposed, but I may still get a usable neg." And bracket - try to get the shot at 800 and see if you can control motion blur at the slower shutter speed - I've learned to get creative with leaning on things, bracing, or trying an angle where there's something to lean on - sometimes being forced to change your POV gives you unique framing you wouldn't have thought of.

Walking around town you should be fine; if you throw up a set, unpack your lights and grip, hire a model and makeup artist and pay a location fee... shooting at box speed or even with a lower ISO might be "optimal". Grabbing shots around town at night may not feel as critical to you.

The shots that have more exposure (metered at an EI of 800) will have better shadows. When compared with the shots metered at an EI of 1600, their highlights may be just as good, just as good with more grain, or less detailed due to over-development.
It depends on the lighting in the scene.
I tend to pay most attention to the mid-tones. I expect giving them extra exposure will be definitely worth it.
Tri-X has a lot of capacity for latitude. What you do with your negatives is also important. To a certain extent, scanning tends to do better with slight under-exposure, and optical printing tends to do better with slight over-exposure.

I've done 400 and 800 on the same roll with one stop push. I couldn't really tell the difference except in a couple frames. I would expect it would be fine.

Saganich said:

I've done 400 and 800 on the same roll with one stop push. I couldn't really tell the difference except in a couple frames. I would expect it would be fine.

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Yes I strongly suspect that if a one stop underexposure with an appropriate push is needed with 400 film such as Tri-X and HP5+ to get the shutter speed required then the loss in quality in the whole set of negatives, as a mix of 400 and 800, is minimal. Well worth the risk in other words

pentaxuser

Go for it.

Thanks everyone for all your replies. I'll be working with neg scans (if I'm allowed to mention that in this forum) which tend to do better at dealing with over exposed highlights rather than under exposed shadows. I'll give it a go and see what happens !

Ste_S said:

This weekend I'll be shooting a fair bit of Tri-X in mixed conditions - indoors/outdoors/daytime/nightime. Hand held with reasonably fast shutter speeds.
In these instances I'd normally shoot it at 1600ISO, with the lab pushing two stops in dev.

However, I wondered if there's any benefit at shooting some shots at 800ISO when the light allows on the same roll if I want a less contrasty shot or more details in the shadows ?
Ie There would be a mixture of shots at 800 and 1600ISO on the same roll, with the lab doing a two stop push in dev.

Click to expand...

I'd shoot at 1200 and develop normally.

In there's significant contrast in the scene you risk getting blacked out shadows; and, of course, underexposure means you'll have to overdevelop it, which will further increase the native graininess of this particular film. Nothing wrong with that if it's the look you're after; but Delta 3200 would be more forgiving in terms of exp latitude, and TMY400 much finer grained and with better shadow gradation even at 800, though it needs more careful metering.