push/exposure, pull/process..

[deantaylor]

<p>hello</p>

<p>A beginner asks about push/pull film exposure/processing...</p>

<p>Is it always the case that they work in tandem to one another, i.e., if we, for example,<br>

<em>push</em> the film we, then, must 'complete the transaction' (metaphor) and <em>pull</em><br>

the exposure...</p>

<p>also...<br>

How does all of this relate to the Zone System?</p>

<p>thank you</p>

<p>Dean</p>

<p> </p>

[deantaylor]

<p>edited to read:<br /> Is it always the case that they work in tandem to one another, i.e., if we, for example,<br /><em>push</em> the <strong>exposure</strong> we, then, must 'complete the transaction' (metaphor) and <em>pull</em><br />the <strong>processing</strong>...<br /> <br /> <em><br /></em></p>

[thirteenthumbs]

<p>Push means give the film less exposure and extend development to <em>push </em>the films sensitivity light.<br>

Pull means to reduce the films sensitivity to light or to reduce development for film that has been given extra exposure.<br>

<br />A Push film with pull processing is a under exposed, under developed film.<br>

A Pull exposure with Push development will result in a over exposed, over developed film.<br>

Push film is expose it at a higher ISO than it is rated.<br>

Pull film is expose it at a lower ISO than it is rated.<br>

Push development is extend development time by 25% or more.<br>

Pull development is to reduce development by 25% or more.<br>

Help?</p>

 

[deantaylor]

<p>yes, thank you, Charles...</p>

<p>What I had in mind (but did not express) was that when we underexpose--push/expose--we<br>

must then balance/compensate by going in the other direction in the processing side<br>

of the equation--push/process. They do work in tandem, doing the opposite thing, but<br>

using the same term...push/push, pull/pull...(learning all the time...).</p>

<p>Best,</p>

<p>Dean</p>

[deantaylor]

<p><em>Push film is expose it at a higher ISO than it is rated.</em><br /> <br /> Then, if a film is rated at a higher sensitivity, it is capable of<br /> (designed to) reacting quickly to a certain quantity of light.<br /> If another film is rated as having a lesser reactance to that same light<br /> quantity, and we have the camera treat it as being faster ('misrepresenting it <br /> to the camera'), it gets shortchanged in the exposure--it is underdeveloped.<br /> We 'bring it back from the dead' by giving it more time in the reviving<br /> juices of the developer bath--and, what a treat it is!<br /> <br /> Kidding aside, there seems to be varied reasons for this two-pronged procedure,<br /> some having to do with pure choice (versus, say, the error of setting the camera incorrectly<br /> when loading the film and attempting to compensate later).<br /> For example, if a scene is imbued with interesting features in half light,<br /> we might pull the exposure (overexpose) in order to capture those details,<br /> but then we must balance/compensate this programme to avoid blown highlights--less<br /> time in the developer ought to do it!<br /> <br /> Another pro I just discovered put it: "The rule of classical fine art photography is: <br />‘expose for the shadows and develop for the highlights'," because, as he notes, we cannot do much of anything at all in post with lost shadows, but we have options with bringing down highlights...<br /> <br />Apparently, details obscured in overexposed film have a better chance at resuscitation<br /> than details lost in shadows...the silver captured the details (they're there!) but, further<br /> light 'buried' them...yet, they can be 'dug out' in post...</p>

<p>I am writing this down in order to inculcate (secure) the facts and ideas, not for your benefit!</p>

<p>Best,</p>

<p>Dean</p>

[deantaylor]

<p>edited to read:<br>

<br>

<em>Apparently, details obscured in <strong>the highlights of</strong> overexposed film have a better chance at resuscitation...</em></p>

[James G. Dainis]

Pulling and pushing of film refers to the development of that film as in push processing or pull processing. It should not be used in reference to the exposure. Even when people use the word "push" when shooting film they mean that they are going to push the development or have it over developed. If an exposure calls for 1/30 sec and you use 1/60 instead you are underexposing the film one stop. Some people may say "1/30 is too slow, I am going to push it to 1/60". They could say, "I am gong to shove it to 1/60" or I am going to advance it to 1/60" or whatever.

 

I would give up on using "pull" and "push" if I were you when talking about exposure. It is only confusing you. You are overexposing to capture more shadow detail or underexposing to bring down highlights.

 

..."we might pull the exposure (overexpose) in order to capture those details,..."

 

In that sentence you should use "...push the exposure (overexpose)..."

 

or

 

you should use "...pull the exposure (underexpose)"..

 

but it is far better to just use "overexpose" or "underexpose" to avoid confusion.

 

Do a quick read of the Zone System here:

 

http://jdainis.com/zone.html

[craig_shearman1]

<p>When you "push" film, you expose it at a higher film speed setting than its official rating. For example, shooting Tri-X at 800 or 1600 instead of 400. Then you develop the film longer, effectively boosting its speed to match. Development time can be around 25 percent to 50 percent extra. Kodak and others have charts that show how much.<br /><br />Lots of people will tell you how this does not really increase the ISO of the film and other details and they are correct. And you will get increased grain and contrast. But the bottom line is that technical details aside it does in fact let you shoot 400 speed film as if it were 800 or 1600. It was very common practice in film days, especially among news photographers. It was done primarily with high-speed films such as 400 and above. Not much point to pushing a 100 speed film when you could buy 200 or 400 instead, but sometimes 100 was all you had with you. It could be done with either B&W or color -- Kodak sold special processing mailers to have their color slide film pushed.<br /><br />Pulling is the opposite -- you expose the film at a lower speed than it is rated for, then reduce the development time. Pulling is much more rare. While photographers often planned to push a roll a stop or two in order to get the higher speed, pull processing was more often done with a roll accidentally got shot at the wrong ISO setting on the meter.<br /><br />In the Zone System, you do sometimes process an individual negative for extra time or less time. But that's generally referred to as "plus one" or "minus one" developing rather than pushing or pulling. A matter of semantics, perhaps, but when people talk about pushing and pulling they generally are not talking about the Zone System.</p>

[ellis_vener_photography]

You have it reversed.

 

With film, increasing the ISO setting on a meter has the effect of decreasing the amount of exposure (underexposing) the

film.

 

To compensate for this underexposure you have to extend (<I>push</I>) the development time to bring up the middle and

shadow values. This can compress tonal separations in the highlights.

 

Pull processing decreases the development time, underdeveloping the negative, as a way of dealing with extremes in

subject/lighting contrast - at the expense of shadow values.

 

 

The operating theory behind pulling and pushing is "difference is detail".

 

A third method used to be standing water bath development where the negative was first presoaked in water, then put into

developer for a short period and then carefully placed in a tray of water where it sits while the developer exhausts itself

more quickly in the more exposed areas of the negative while continuing to work on the less exposed areas. It was a

pain in the ass and I never got it to work right when developing negative film, but with prints it worked very well.

 

From what I recall water bath development didn't really work on TMax films. By accident John Sexton figured out that if he

doubled the dilution of his TMax developer he was able to pull a lot of detail out of extreme highlights while retaining

good shadow values.

 

If you don't know who John Sexton is, I suggest you look him up.

[deantaylor]

<p><em>You are overexposing to capture more shadow detail or underexposing to bring down highlights.</em><br>

<em> </em><br>

<em><br /></em>What about those pros who do <strong>both</strong>: they overexpose to capture more shadow detail, and then to<br>

bring down the now-aggravated highlights, they then 'pull' process--leave it in the developer for a shorter<br>

amount of time? As Charles noted above: <em>Pull film is expose it at a lower ISO than it is rated...Pull </em><br>

<em>development is to reduce development by 25% or more.</em><br>

<em> </em><br>

Sincere thanks to both you and Charles--I have a better sense of the uses of pushing or pulling film...<br>

We may push or pull in the event we set the ISO incorrectly at film loading...<em>or</em>, we may push or pull<br>

with deliberation--before the fact--for example, 1) to capture detail in expected shadows, and then, 2) bring down<br>

highlights we 'aggravated' when we purposefully overexposed the film in the first place...</p>

<p>Best,</p>

<p>Dean</p>

<p><em> </em><br>

<em> </em><br>

<em> </em><br>

<em> </em></p>

[Dustin McAmera]

<p>This all seems a bit high-flown to me. I push film to keep on photographing hand-held as it starts to get dark.</p>

[James G. Dainis]

"What about those pros who do both: they overexpose to capture more shadow detail, and then to

bring down the now-aggravated highlights, they then 'pull' process--leave it in the developer for a shorter amount of time?"

 

What about them? That is perfectly valid. Overexpose and underdevelop is a method that photographers use. Sometimes even routinely. Overexpose and underdevelop will get softer facial textures (less pores and wrinkles). Underexpose and overdevelop will get stronger facial textures (more pores and wrinkles).

[deantaylor]

<p><em>A beginner asks about push/pull film exposure/processing...</em><br>

<em> </em><br>

<em><br /></em>I was careful to note this at the beginning of the thread to indicate to certain...'anxious'<br>

types that the inquiry was not a challenge to their 'expertise'...</p>

<p><em>What about those pros who do both:</em><br>

response:<br>

<em>"What about them?"</em><br>

<em> </em><br>

Do us both a favor and stay off my posted threads...okay?</p>

<p> </p>

[glen_h]

<p>I tend to think of it in terms of "push up" (pushing to a higher EI) and "pull down" to lower the EI.</p>

<p>The exact effect of "push" is complicated. Most films push easily one stop, and maybe only okay two stops.</p>

<p>You might also look at Diafine, a compensating developer that is supposed to be able to develop the shadows more without overdeveloping the highlights. It has been my favorite for almost 50 years, since my grandfather taught me about how to use it. (Though it doesn't help so much with more modern films.)</p>

[James G. Dainis]

I didn't understand what you were asking with "What about those pros..." but I tried to answer what I thought you were asking.