Pushing/Pulling questions...

ChristopherCoy · May 11, 2020

Too much technical reading for me leads to a state of massive confusion. So I'd like to see if I have this correctly.

Shooting at box speed of 400:
-metering for 200, over exposes film, so you're pushing it?
-metering for 800, under exposes film, so you're pulling it?

Is shooting and metering it at 400, and adding +1 or -1 EV (Nikon F5) the same thing as the above?

And:
-if you meter for 200, you decrease development times by 20%?
-if you meter for 800, you increase development times by 20%?

Or do I have all of this exactly reversed?

grain elevator · May 11, 2020

ChristopherCoy said:
Too much technical reading for me leads to a state of massive confusion. So I'd like to see if I have this correctly.

Shooting at box speed of 400:
-metering for 200, over exposes film, so you're pushing it?
-metering for 800, under exposes film, so you're pulling it?

Nope, that's called overexposing and underexposing.

ChristopherCoy said:
Is shooting and metering it at 400, and adding +1 or -1 EV (Nikon F5) the same thing as the above?

Yes.

ChristopherCoy said:
And:
-if you meter for 200, you decrease development times by 20%?
-if you meter for 800, you increase development times by 20%?

Or do I have all of this exactly reversed?

That's right (although 20% is just a starting point). And this (altering exposure and development) is called pulling and pushing, is this order.

MattKing · May 11, 2020

Technically, pushing and pulling refer only to changes in development, although they are usually employed in conjunction with intentional under-exposure (push) or intentional over-exposure (pull)
And all they really do is change contrast and change the shape of the curve.
Their effect on the film speed is marginal - pushing increases speed a tiny bit, and pulling decreases speed a tiny bit.
There are two reasons why one would increase development.
The first - push or pull development - is employed to deal with situations that force the photographer to intentionally under-expose lr over-expose their film.
In the case of intentional under-exposure - e.g. shooting Tri-X at an EI of 1600 instead of the ISO speed of 400 - you employ increased development ("push") to improve the appearance of the lighter shadows and lower mid-tones by increasing their contrast. This tends to make the results appear nicer than regular development does. You need to understand though that this does nothing to retrieve detail that has been lost in the dark shadows due to under-exposure - they are gone for good. This also tends to decrease the quality of rendition of the highlights, and highlight rendition plays a huge roll in the satisfactory appearance of an image. So for those reasons, under-exposure plus a push development needs to be approached cautiously - it will give you less quality than a normally exposed and normally developed image.

Your Tri-X plus Rodinal examples look a lot like the results obtained from an under-exposure plus a push development - particularly the push development part.

Pull development is usually employed to deal with over-exposure that either occurs because of error or because of limitations imposed by equipment or techniques - e.g. cameras that don't offer a choice of many shutter speeds and apertures. The reduction in development helps to counteract the excess exposure in the highlights particularly, but imposes a not necessarily wanted reduction in overall contrast.

The other reason to increase development is that an increase in overall contrast - an expansion - can be used to deal with low contrast lighting and subjects. This is what Zone system people use to fit their negatives to their vision and the printing paper or process they are using. This is obviously most useful with single sheets. When you see someone referring to N+1 or N+2 development, that is what they are referring to. They will also usually decrease exposure slightly - much less than the under-exposure that usually accompanies a push development.

A similar analysis applies to a reduction in development in order to achieve a reduction in contrast - a contraction - which is used to deal with high contrast lighting and subjects. This too is obviously most useful with single sheets. When you see someone referring to N-1 or N-2 development, that is what they are referring to. They will also usually increase exposure slightly.

Here is an example of a shot from a roll that I used expansion with, due to the flat nature of the light that day:

ChristopherCoy · May 11, 2020

MattKing said:
Technically, pushing and pulling refer only to changes in development, although they are usually employed in conjunction with intentional under-exposure (push) or intentional over-exposure (pull)
And all they really do is change contrast and change the shape of the curve.

So for simplification purposes, over exposed negatives get under developed, because you are "pulling" them down. Like sliding the "brightness" slider down from white to black. And underexposed images get over developed, because you are "pushing them" up, like moving the slider from black to white. But, no amount of development can make up for lost elements in the shadows or highlights.

MattKing · May 11, 2020

ChristopherCoy said:
But, no amount of development can make up for lost elements in the shadows or highlights.

More accurately, "no amount of development can make up for lost elements in the shadows, and increased development makes it much more difficult to retrieve all of the elements in the highlights".

Paul Howell · May 11, 2020

We use to push film, TriX and HP5 when shooting in very dim light, the method was to expose for the highlight and let the shadows fall where they may. I would be sent to shoot a basketball game, 60s gym lighting, push TriX to 3200 and develop +150%, or if lighting was better TriX in Diafine at 1600, which was not really a push, shadow details were maintained. This is not be confused with the Zone System concept of contraction and expansion in which the film is shot at a tested E.I with development adjusted to control contrast. Meter the shadows and develop for the highlights. Although some would agure that changing the developing time changes the speed of a film.

ChristopherCoy · May 11, 2020

Paul Howell said:
We use to push film, TriX and HP5 when shooting in very dim light, the method was to expose for the highlight and let the shadows fall where they may. I would be sent to shoot a basketball game, 60s gym lighting, push TriX to 3200 and develop +150%, or if lighting was better TriX in Diafine at 1600, which was not really a push, shadow details were maintained. This is not be confused with the Zone System concept of contraction and expansion in which the film is shot at a tested E.I with development adjusted to control contrast. Meter the shadows and develop for the highlights. Although some would agure that changing the developing time changes the speed of a film.

Hell, I can barely understand the current subject, without the added compmlexity of the zones.

jtk · May 11, 2020

MattKing said:
Technically, pushing and pulling refer only to changes in development, although they are usually employed in conjunction with intentional under-exposure (push) or intentional over-exposure (pull)
And all they really do is change contrast and change the shape of the curve.
Their effect on the film speed is marginal - pushing increases speed a tiny bit, and pulling decreases speed a tiny bit.
There are two reasons why one would increase development.
The first - push or pull development - is employed to deal with situations that force the photographer to intentionally under-expose lr over-expose their film.
In the case of intentional under-exposure - e.g. shooting Tri-X at an EI of 1600 instead of the ISO speed of 400 - you employ increased development ("push") to improve the appearance of the lighter shadows and lower mid-tones by increasing their contrast. This tends to make the results appear nicer than regular development does. You need to understand though that this does nothing to retrieve detail that has been lost in the dark shadows due to under-exposure - they are gone for good. This also tends to decrease the quality of rendition of the highlights, and highlight rendition plays a huge roll in the satisfactory appearance of an image. So for those reasons, under-exposure plus a push development needs to be approached cautiously - it will give you less quality than a normally exposed and normally developed image.

Your Tri-X plus Rodinal examples look a lot like the results obtained from an under-exposure plus a push development - particularly the push development part.

Pull development is usually employed to deal with over-exposure that either occurs because of error or because of limitations imposed by equipment or techniques - e.g. cameras that don't offer a choice of many shutter speeds and apertures. The reduction in development helps to counteract the excess exposure in the highlights particularly, but imposes a not necessarily wanted reduction in overall contrast.

The other reason to increase development is that an increase in overall contrast - an expansion - can be used to deal with low contrast lighting and subjects. This is what Zone system people use to fit their negatives to their vision and the printing paper or process they are using. This is obviously most useful with single sheets. When you see someone referring to N+1 or N+2 development, that is what they are referring to. They will also usually decrease exposure slightly - much less than the under-exposure that usually accompanies a push development.

A similar analysis applies to a reduction in development in order to achieve a reduction in contrast - a contraction - which is used to deal with high contrast lighting and subjects. This too is obviously most useful with single sheets. When you see someone referring to N-1 or N-2 development, that is what they are referring to. They will also usually increase exposure slightly.

Here is an example of a shot from a roll that I used expansion with, due to the flat nature of the light that day:
View attachment 245994

Very well expressed. fwiw "push" and "pull" aren't typically used in Zone System discussions because it's given that the exposure and development are points of departure...they don't pivot around box speed or rigid assumptions about development/time.

"push" and "pull" terms assume a fixed, conventional exposure and development...typically based on Kodak or other published numbers.

Professionals shooting Ektachrome commonly had labs push their film (rarely pull it).

Kodak's Kodachrome operation in South San Francisco was willing to push Kodachrome in same day processing for a small fee..it did look conventionally good at 1X ""N+1...perhaps at the expense of highlights). I think most of us rated 35mm 64 @ 80 in order to gain deeper tones with Kodak's normal processing....worked beautifully with studio strobes and soft boxes. On one occasion I asked Kodak to process a woman's Kodachrome @ 2X...it looked as good as you might expect from a gory-bloody looking surgical scene.

David Allen · May 12, 2020

ChristopherCoy said:
Hell, I can barely understand the current subject, without the added compmlexity of the zones.

OK, let’s take a different approach.

If you meter a 400 film at 200 you will achieve more shadow detail. This MAY cause your highlights to become too dense and therefore difficult to achieve details on the print. If this is the case you reduce the development time to compensate and bring the highlights under control. The starting point for ascertaining the correct development compensation time is to begin tests with 20% less development time.

If you meter a 400 film at 800 you will loose shadow detail. As there is little to no shadow detail you will quickly achieve a black on the print but you will find that the mid-tones and highlights will look grey and the overall print will lack contrast. If this is the case you increase the development time to compensate so that the mid-tones and highlights are denser, have more contrast and therefore look much better on the print. The starting point for ascertaining the correct development compensation time is to begin tests with with 20% more development time.

However, you have to be aware that all of the above relates to a scene with a 'normal' range of tones. A low contrast scene will probably benefit from push processing (look at Matt King's example photograph).

A scene with high contrast (such as this one attached where the bottom right hand side is in shadow and depicts an old plastered wall darkened by smoke form the bombing of Berlin and over 40 years of soot from the brown coal that was used for heating in East Berlin and the rest shows a newly painted white wall with part of it in full sunlight) will probably benefit from pull processing.

So specifically to your questions:

Shooting at box speed of 400:

metering for 200, over exposes film, so you're pushing it? No, the correct term is pulling the film because you are pulling back the development and density of the highlights on the negative
metering for 800, under exposes film, so you're pulling it? No, the correct term is pushing the film because you are pushing the development time to ensure that highlights have more density on the negative

Is shooting and metering it at 400, and adding +1 or -1 EV (Nikon F5) the same thing as the above? Yes, this is exactly the same. 1 EV is equal to one stop.

Therefore, setting +1 EV on your Nikon will deliver one more stop of exposure and is the equivalent of exposing your 400 film at 200.
Setting -1 EV on your Nikon will deliver one stop less of exposure and is the equivalent of exposing your 400 film at 800.

And:

if you meter for 200, you decrease development times by 20%? Yes, this is correct BUT ONLY if you find that normal development time causes the highlights to become too dense on the negative.
if you meter for 800, you increase development times by 20%? Yes, this is correct BUT ONLY if you find that normal development time causes the mid-tones and highlights to have a lack of density and contrast on the negative.

Bests,

David (please note the temporary address for my website: http://dsallen.carpentier-galerie.de)

ChristopherCoy · May 12, 2020

Thanks David. That explanation was very easy for me to visualize, and I appreciate it. And now that I can visualize it, I actually have a photograph of it in my mind, since I often used to do this with my digital slr and shutter speeds. I would increase my shutter speeds to darken or "underexpose" for the highlights, and decrease my shutter speeds to brighten or "overexpose the highlights.

David Allen · May 12, 2020

Hi there,

I am very glad that my explanation helped you.

Have great fun and pleasure on your journey with analogue photography.

If you ever need more help, please do not hesitate to contact me.

Bests,

David.

carencrobuzzard · May 30, 2020

MattKing said:
Technically, pushing and pulling refer only to changes in development, although they are usually employed in conjunction with intentional under-exposure (push) or intentional over-exposure (pull)
And all they really do is change contrast and change the shape of the curve.
Their effect on the film speed is marginal - pushing increases speed a tiny bit, and pulling decreases speed a tiny bit.
There are two reasons why one would increase development.
The first - push or pull development - is employed to deal with situations that force the photographer to intentionally under-expose lr over-expose their film.
In the case of intentional under-exposure - e.g. shooting Tri-X at an EI of 1600 instead of the ISO speed of 400 - you employ increased development ("push") to improve the appearance of the lighter shadows and lower mid-tones by increasing their contrast. This tends to make the results appear nicer than regular development does. You need to understand though that this does nothing to retrieve detail that has been lost in the dark shadows due to under-exposure - they are gone for good. This also tends to decrease the quality of rendition of the highlights, and highlight rendition plays a huge roll in the satisfactory appearance of an image. So for those reasons, under-exposure plus a push development needs to be approached cautiously - it will give you less quality than a normally exposed and normally developed image.

Your Tri-X plus Rodinal examples look a lot like the results obtained from an under-exposure plus a push development - particularly the push development part.

Pull development is usually employed to deal with over-exposure that either occurs because of error or because of limitations imposed by equipment or techniques - e.g. cameras that don't offer a choice of many shutter speeds and apertures. The reduction in development helps to counteract the excess exposure in the highlights particularly, but imposes a not necessarily wanted reduction in overall contrast.

The other reason to increase development is that an increase in overall contrast - an expansion - can be used to deal with low contrast lighting and subjects. This is what Zone system people use to fit their negatives to their vision and the printing paper or process they are using. This is obviously most useful with single sheets. When you see someone referring to N+1 or N+2 development, that is what they are referring to. They will also usually decrease exposure slightly - much less than the under-exposure that usually accompanies a push development.

A similar analysis applies to a reduction in development in order to achieve a reduction in contrast - a contraction - which is used to deal with high contrast lighting and subjects. This too is obviously most useful with single sheets. When you see someone referring to N-1 or N-2 development, that is what they are referring to. They will also usually increase exposure slightly.

Here is an example of a shot from a roll that I used expansion with, due to the flat nature of the light that day:
View attachment 245994

my question is about pushing and pulling polymax 400. this film seems to have very limited changes when pushed with +1, +2, -1,-2. what say you?

MattKing · May 30, 2020

carencrobuzzard said:
my question is about pushing and pulling polymax 400. this film seems to have very limited changes when pushed with +1, +2, -1,-2. what say you?

Welcome to Photrio.
I don't recognize that film. Are you perhaps meaning to refer to TMax 400?
If so, you may note that Kodak recommends no change in development if you under-expose it by one stop. I certainly have seen change when I've tried to use it with two stops of under-exposure and the two stop push development recommended by Kodak.
I don't do enough pull developing to help you there.

carencrobuzzard · May 30, 2020

yes i did mean tmax, thanks. ok next question. i overexposed by 2 stops (equivalent of asa 1600) hoping to show some detail in the shadow area then i reduced development time by 30%. the highlights seem printable (with some burning in) but still no detail in the shadows. what next?

MattKing · May 30, 2020

carencrobuzzard said:
i overexposed by 2 stops (equivalent of asa 1600)

A 2 stop over-exposure would be the equivalent of ISO 100, not ISO 1600.
Are you sure you didn't under-expose by two stops?
Assuming you you did increase exposure by two stops, I would ask how you metered the scene. Depending on the scene, it may be that the shadows need more exposure than that.
Shadow illumination varies widely.

carencrobuzzard · May 31, 2020

MattKing said:
A 2 stop over-exposure would be the equivalent of ISO 100, not ISO 1600.
Are you sure you didn't under-expose by two stops?
Assuming you you did increase exposure by two stops, I would ask how you metered the scene. Depending on the scene, it may be that the shadows need more exposure than that.
Shadow illumination varies widely.

yes you are correct again, thanks. to meter the light i used incident light, over exposed by three stops and developed 30% less, still nothing in the shadows, highlights would need a lot of burning-in

138S · May 31, 2020

carencrobuzzard said:
yes you are correct again, thanks. to meter the light i used incident light, over exposed by three stops and developed 30% less, still nothing in the shadows, highlights would need a lot of burning-in

A longer development time increases contrast, the gradient is higher, but you get little additional shadow detail, not much. With overdeveloping you make deep shadows a bit more printable in the darkroom, but if you are to scan then there is not much benefit in overdeveloping because with photoshop you adjust the image easier than in the darkroom.

Some developers slightly increase film speed.

Incident matering is great in many situations, but when wanting to evaluate film response it's better to use spot meter to now the precise exposure each interesting spot received.

MattKing · May 31, 2020

It may be that your scene has too high a SLR (Scene Luminance Range) to be captured without something like HDR.
The Zone system is designed to deal with shadow areas that have detail and are within a few stops from highlights that have detail.
This needs to be distinguished from scenes where one expects to have featureless shadows or featureless highlights.
It has been my experience that many photographers have a tendency to make decisions based on dark shadowed areas that ought to be featureless in the print, rather than somewhat lighter shadowed areas that ought to retain detail.
Take an incident reading with the meter in the same light as the light that illuminate the shadowed areas, and compare it with your main incident reading - how many stops difference are there between the readings.
The nature of the subject also matters. If your shadowed areas are also made up of dark materials, the difficulty of rendering detail in those areas may be insurmountable.

carencrobuzzard · May 31, 2020

yep, all true. going to give up on my flirtation w the zone system and use my average grey card like i have been for years

MattKing · May 31, 2020

If you are using an incident meter, there is no point to using a grey card to determine exposure.
And the visualization part (or if you follow Minor White, the pre-visualization part) of the Zone System remains invaluable.

carencrobuzzard · May 31, 2020

hey, another question for you regarding the SLR (Scene Luminescence Range). landscape, sunny day, spotmeter. i take a reading on a highlight area where i hope to have some detail on the negative (tmax 400 at 400) ,then a reading in the darkest area that i hope to have some detail. there may be four or five f-stops between the two. this slr may well be beyond the range of any film. the slr of any given film may be 4 or so fstops. have you ever seen any manufactures technical data sheet giving a number representing the slr of a film? thanks

MattKing · May 31, 2020

4 or 5 stops is a lot less than is available with T-Max 400 exposed and processed as a negative.
Even slide film can record that range.

Jonnymm · Jun 1, 2020

In terms with BW film, I've seen the photographer Andre D Wagner shoot Tri X developed at 1600 but rated at 800 when taking measurements for the shadows. Where I am (Ireland) in autumn/winter it's pretty dim out there so something to think of in the future.

carencrobuzzard · Jun 1, 2020

MattKing said:
4 or 5 stops is a lot less than is available with T-Max 400 exposed and processed as a negative.
Even slide film can record that range.

hey, me again with another question, re the term and concept of SLR. for years, i have been aware, in the back of my mind, of the existence of the range of luminescence being more than the film could record. but i never had heard the phrase. so my question is, have you ever read any film manufacturers technical data info stating the films SLR number in addition to asa, iso, etc?

carencrobuzzard · Jun 1, 2020

hey, me again with another question, re the term and concept of SLR. for years, i have been aware, in the back of my mind, of the existence of the range of luminescence being more than the film could record. but i never had heard the phrase. so my question is, have you ever read any film manufacturers technical data info stating the films SLR number in addition to asa, iso, etc?

Pushing/Pulling questions...

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