Where does the push/pull happen in the process?

[Christian Janss]

One more question/issue.

 

I plan to test the steps in my previous post. I read in one of David's other posts that a good way to do a pull/push test is to do three tests:

 

normal exposure / normal process

one-stop over / one-stop pull

2/3-stop over / process normal

 

What would you recommend to include in the frame? I was thinking of using a white subject on a dark background and vica verca, one ext. & one int., and maybe include something red too since I've read pushing/pulling effects the reds. Any other ideas/recommendations/things I should test for?

 

thanks again,

Christian

[Dominic Case]

If you can get a greyscale or Macbeth chart, include that. Otherwise, try to get a range of tones - in particular, someting like crumpled black velvet (which will be very black but will show a little detail in the folds) and similarly with a bright white highlight.

 

Bracket your exposure - that is, do a series of takes at normal, overexposed and underexposed. You might need to be 2 stops off either way to see differences.

 

Then do each of the sets of tests three times - once for normal process, once for push, once for pull processing.

 

That way you have all combinations covered.

 

If you want to cut back on the number of tests, cut out the overexpose/push one and the underexpose/pull one, as they will be a long way off standard. But it is very important always to have a refernece point - so always have a normal exposure test in each processing run, and have the full range of exposures in the normal process run.

 

 

A short answer to your previous question - i.e would pushing one stop in processing look the same as overexposing one stop in the camera?

 

Exposure and process variations aren't really the same. Push processing tends to increase contrast, but doens't really get you much more detail in the shadows. Overexposure lifts the entire scale. You can't fully compensate for underexposure by push processing (if there wasn't enough exposure to record a shadow detail, then no amount of processing will bring it out).

 

What pushing actually does (for an underexposed negative) is restore the mid-tones to where they would be if you had exposed normally and processed normally. SO you have a neg you can print easily or transfer easily. But the highlights and shadows won't be exactly the same.

 

And that is what pusn and pull processing is about. Often you can get away with a stop over or under - grading/timing when you print or transfer will bring the image back to normal: but if you push pocess, you are changing the way the film responds across the entire scale.

[David Mullen ASC]

You're confusing yourself by trying to think of these processes in combinations rather than separately.

 

Pushing increases density during processing.

 

Pulling decreases density during processing.

 

Overexposure increases density.

 

Underexposure decreases density.

 

You can combine these however you want. You can underexpose by one stop and then pull-process by one stop and end up with a negative that looks two-stops underexposed. If for some reason you wanted that look. Maybe for a special lower-contrast moonlight effect where you would leave the image looking two-stops darker than normal.

 

You can correct a dense or thin negative further in print color timing or during the video transfer of the negative, so you don't necessarily have to end up back at "normal" density in your combinations of exposing and processing tricks. So a negative that is a half-stop or so denser (more exposed) than normal can be printed "down" to normal in printing, or color-corrected back down to normal in the video transfer.

 

Ending up with a slightly overexposed or denser negative is generally a good thing, but it also depends on the look you want to achieve.

 

My final advice is to not mess with special processing unless you have a good grasp of normal processing. Once you've mastered that pretty well, you'll have a better understanding of when you might need to pull or push process.

[Phil Gerke]

What about reversal stocks? Specifically cross processing color reversal film. In order to get a denser negative you would over expose the revesal stock correct? Wouldn't your negative be too dense? Would you pull when creating the negative? Sorry to open up a whole new can of worms.

 

Thanks!

[David Mullen ASC]

It's a non-standard process with some unpredictable results. Some people find that the resulting negative from cross-processing is a litle dense (overexposed) so some compensate by slightly underexposing. But the problem is that reversal has limited latitude and the contrast is even higher when you cross-process, so you have a narrow window to get the exposure right -- otherwise, too much bright detail is either burned-out, or the opposite, too much shadow detail is lost. So you don't have much flexibility to over or underexpose.

[Dominic Case]

If you cross-process reversal stock (i.e. in a colour negative bath) then it behaves like a negative. Simple as that. So push processing (longer or hotter developer) increases density - and a bit of contrast; and increasing exposure also increases density.

 

As David points out, it's a non-standard process with non-standard results, so it's hard to talk about "normal" exposure for cross-processed reversal stock.