[Beepaitch]

Following with interest! Just started a roll of HP5 at 800, a first for me. Kind of wishing I’d gone +2 now!

[szs]

This thread's inspired me to try to push a roll of film or two! I'm currently halfway through a roll of Ilford 3200 that I'm using to have fun with my telephotos

Same here! Thanks, OP!

[tuco]

Following with interest! Just started a roll of HP5 at 800, a first for me. Kind of wishing I’d gone +2 now!

Pushing HP5+ one stop is not a push really. It has so much latitude you can shoot it at EI800 and develop it normally. Same with Kodak's 400TX. Kodak says right in their the data sheet you shoot at EI800 and use a normal development time. When you push film, you can't magically get shadow detail that was never recorded even if you use a specific film or developer.

If a good exposure captures, say, 12-stops of light at box speed for a 400 film, shooting the exact same scene by reducing your exposure by 3 stops for an EI 3200 will cut off a lot of shadows. Over developing film can't bring it all back because it was not recoded on the film. If you can get the same shadow detail using a 3-stop push as at box speed, you didn't have the equivalent exposure as box speed just reduced 3-stops.

[Beepaitch]

shoot it at EI800 and develop it normally

Ok I think I’ve misunderstood something fundamental then.

Say I have a fictional 1 frame 400 iso film loaded, shot at 400EI, and I take a pic metered at 100th/f16.
Then a second film, identical setup and scene except it’s 800EI, I.e camera set at 800.
Then I develop both films identically. Am I wrong to think the second shot will be 1 stop stop darker?

[tuco]

Ok I think I’ve misunderstood something fundamental then.

Say I have a fictional 1 frame 400 iso film loaded, shot at 400EI, and I take a pic metered at 100th/f16.
Then a second film, identical setup and scene except it’s 800EI, I.e camera set at 800.
Then I develop both films identically. Am I wrong to think the second shot will be 1 stop stop darker?

Oaky just talking about the negative as seen on a light table and not a second generation image that was produced from the negative because that adds a huge variable in this discussion. Yes you'll see it darker (lighter negative if less exposure) if it was a picture predominantly of a white wall or sky kind of thing. But a negative that has a healthy range of tones and excellent dynamic range it would be hard to notice, I'd say. But that depends a lot on the individual person too.

I have an idea in mind to show this graphically but I'll have to put it together so maybe keep an eye out for that. But think of a 20-step grey scale going from black to white. Each step represents a stop. And each step is further divided into 1/3s like the metering scale on a camera. You've seen them. Look at step 7 and let's call that your middle grey exposure for a scene ( what your camera picked for example). With films like HP5/400TX, you are certain to capture 4 steps below step-7, your middle grey, and how many steps above step-7 you capture is a function of the film, exposure, developer and development time.

Now move your middle grey point up or down one-step on this 20-step scale. It's hard to notice much change in the really dark areas 4 steps below your middle grey in this new position. You might need a densitometer to notice a whole step has dropped off the scale from what it was before, for example. I think I can show this graphically better but my point is think of your exposure as a big, 20-step grey scale where your middle grey points somewhere on it and you can grab only, say, 10-12 steps from that scale starting from where your middle grey is pointing at.

Exposure on this 20-step grey scale is like a bellows on a view camera. The folds of the bellows next to the camera body represent the dark steps of your exposure + development and the folds next to the end your pulling represent the white steps. When you pull the bellows, the folds don't separate much next to the camera body but the folds do stretch farther apart on the other end. A lot of change in the white steps while much less change in the dark steps. How far you pull it is like your development time. A good development time means you pulled that bellows far enough that it places that middle grey step and 3 steps above it at certain target densities that you can measure. These target densities are a function of the enlarger type (eg condenser/diffusion) you'd use to reproduce the negative ( which can be up to 3 minutes difference in development time ). In the case of scanning only, it can reproduce the range of both of these establish density targets just fine and more, I'd say. The target density difference between diffusion and condenser enlarger can equate to about a stop exposure difference. And if one person gets a perfect grade 2 print from their diffusion enlarger and another gets a perfect grade 2 print from their condenser enlarger using the same stuff, that should say scanning gives you a whole stop to play with in targeting your development time.

[Chris_K]

Exposure on this 20-step grey scale is like a bellows on a view camera

That is a very interesting and transparent comparison!

[titrisol]

Yeah, that's why I picked HP5 for this. Just seemed to be a better option for pushing 3 stops without getting super dark and grainy.

DDX is awesome for pushing HP5; the grain you got is beautiful
Delta400 works as well, but doesn;t have the same "look"