Incense

by Bart Arondson

submit your photo


Hall of Fame
View past winners from this year

Please participate in Meta
and help us grow.

Take the 2-minute tour ×
Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. It's 100% free, no registration required.

The terms push and pull come from the days of film processing, and there's more on that here and here, but essentially they refer to increasing or decreasing the chemical processing time to account for intentional or unintentional under/over-exposure of the film roll.

When it comes to digital, we're no longer bathing films in chemicals, but are adjusting the exposure compensation knob on the camera, or an exposure slider in Lightroom/Aperture/Photoshop/etc. So I'm wondering if these terms are still relevant to digital photography, and exactly how they can/should be used—they certainly seem to be used by experienced photographers, so I want to make sure I'm understanding precisely what they mean.

First, which way is which? and is there a simple mnemonic or trick to remember?

Second, can these terms be used to refer just to intentionally over/under-exposing a photo (relative to the recommended metering) for artistic effect? Or do they always refer to a two-stage process of under/over-exposing in camera, then a corresponding & opposite adjustment in post-processing?

share|improve this question

3 Answers 3

up vote 6 down vote accepted

The terms push and pull are still relevant in the sense that they are still used and understood by many enthusiast photographers. But they are probably not as common as they once were. New terms, such as expose to the right describe the same concept using different words.

If you underexpose when taking the shot, then you push the exposure in editing to raise it. Conversely, if you overexpose when taking the shut, then you "pull" the exposure back down in post. Although there may be those who use push or pull when referring to intentionally over or underexposed photos that are not corrected at some point in the workflow in my experience they seem to always be used in the context of offsetting adjustments.

share|improve this answer
1  
Yeah, ETR is a good equivalent of shooting for a pull (contrast/tone management), but the only real analog for push is "I'm out of ISO and will have to try to fix it in post". You can easily get the contrast boost, grain, etc., in "development" without any of the bad that comes with underexposure. –  user2719 Mar 26 at 16:49
    
Thanks for those explanations. For the memory device, I'll think of someone standing at the zero point (left) of the histogram in the post-processing tool, either pushing or pulling the histogram to return it to correct exposure, and in the camera it's about getting the histogram at the end ready for that push/pull. –  drfrogsplat Mar 26 at 23:20

Along other expressions like unsharp mask etc. they are used in the digital environment in an analogus way to their classic usage.

Most common is "pushing" by correcting to the plus, preferrably while "developing" (another of these expressions) a jpeg or tiff out of a raw. Correction to the minus corresponds to "pulling".

share|improve this answer

I just thought about that the other day: using ISO adjustment to explore the tradeoff between sensor gain and other settings for indoor flash photography, I recalled that 1000 speed film was really just 800 with the developing "pushed". That was the only time I've thought about the term in digital photography workflow. It seems that anybody younger than my EOS 620 has no idea what those terms mean. It has not, like some other terms, been blessed with Photoshop icons paying homage to the original concept. I don't think anything is properly analogous, with the closest thing being "ISO extension", allowing the sensor gain to be turned higher than it is really meant for at the published level of quality.

Exposure compensation is not the same thing. Manipulating the exposure/highlights/darks/shadows/contrast in Lightroom or with Curves is a completely different thing.

Sure, you can brighten a picture that's underexposed because you were maxed out on your exposure settings, and that might be analogous enough for some; but I think it refers specifically to changing the sensitivity of the imaging media (film or semiconductor) as opposed to any manipulation of the data after exposure.

Pushing is not printing darker by increasing the exposure on the enlarger. It's getting a negative that has lighter areas by changing the details of the chemical reactions that fix the latent image. It makes the film more sensitive, beyond its stated range. That is, you are pushing the limits of the specification of the material. (does that help you remember it?)

share|improve this answer
    
To change the sensitivity of the media a little more than just a different development process is needed. Sensitivity is about latent image. –  Iliah Borg Oct 20 at 12:52
    
So, maybe "pushing" is like affecting the amplifier and A/D conversion step, if the photoelectron capture is analogous to the zapped AgX crystal: the latent image, which is not itself changed. Using a different time, temperature, concentration, or higher energy developer affects the mapping of the latent image to the visible density. Affecting the amplification and A/D stage is the analogous process. So "pushing" means setting those parameters higher than spec'ed for the nominal performance curve. –  jdlugosz Oct 20 at 13:22
    
I would say, yes, ISO setting on a digital camera is more like a push, with no pull equivalent. Another point of view would be manipulating first development of a slide film. –  Iliah Borg Oct 20 at 14:03

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.