Pushing and pulling

Barney

Barney

Suspended / Banned
Messages
3,043
Name
Wayne
Edit My Images
No
No matter how many times I have read about pushing and pulling it is still not sinking in which way round it goes first with the film and then with development, obviously a deficiency on my part.

I am also in a quandary with the film aspect, am I better off using a 100 iso film at 400 because of the better grain and tone or using a 400 film?
 
You push forward and pull back, yes? So, on the assumption that you see faster as forward (I suppose as a faster runner is forward of a slower one in a race) pushing a film makes it faster. Which isn't actually true - extending development just gives more chance for any shadow detail to come up. Needed because the shadows are what suffer when you underexpose, which you do when you cut 2 stops exposure to use a 100 film at 400.

And because you need more shadow detail, you give more development and hope for the best.

With pulling, you overexpose and cut development to save the highlights from blocking.
 
Last edited:
On the second question, I have read people who say using a slower film and pushing it hives finer grain than using a faster film to start with.

On the other hand, more development gives more grain, as does more exposure, so in theory it will be swings and roundabouts. The lower exposure reduces the grain, so that the extra development can increase it again.

The best way to reduce grain in a print is to use a larger negative.
 
I have always found that the least bad results I obtained from film was to use it at its rated speed and develop it as per the instruction leaflet for the developer.

Whenever I strayed from that path, I wasn't satisfied with the outcome. Of course everyone has their own approach and should follow that if it pleases them. For me, KISS (keep it simple, stupid) has always paid off handsomely, so that's the only recomendation I can usefully give.
 
StephenM said:
You push forward and pull back, yes? So, on the assumption that you see faster as forward (I suppose as a faster runner is forward of a slower one in a race) pushing a film makes it faster. Which isn't actually true - extending development just gives more chance for any shadow detail to come up. Needed because the shadows are what suffer when you underexpose, which you do when you cut 2 stops exposure to use a 100 film at 400.

And because you need more shadow detail, you give more development and hope for the best.

With pulling, you overexpose and cut development to save the highlights from blocking.
Click to expand...
This is exactly my understanding problem.

Pushing = more light
Pulling = less light

but you seem to be saying the opposite Stephen
 
AndrewFlannigan said:
I have always found that the least bad results I obtained from film was to use it at its rated speed and develop it as per the instruction leaflet for the developer.

Whenever I strayed from that path, I wasn't satisfied with the outcome. Of course everyone has their own approach and should follow that if it pleases them. For me, KISS (keep it simple, stupid) has always paid off handsomely, so that's the only recomendation I can usefully give.
Click to expand...
Thanks for trying to help Andrew, for my development times I have been using Film Dev app on recommendation here and this usually resulted in dark negatives hence my exploration of varying my options. Where are you obtaining the instruction sheets for the developers? I considered the instructions on the bottle, perhaps incorrectly, as generic guidelines which could be improved when modified for specific film types.

I am also a big fan of the acronym KISS and feel that is what I am trying to do, come up with the simplest solution!
 
Barney said:
This is exactly my understanding problem.

Pushing = more light
Pulling = less light

but you seem to be saying the opposite Stephen
Click to expand...

You push a film when there isn't enough light to use the aperture and shutter speed you want (e.g. black cat in unlit coal cellar when you use 1/1000th second to stop the motion, and f/22 to get maximum depth of field to cover the area it's moving though). You're attempting to get a denser negative with less light than the film manufacturers recommend. If you prefer an inaccurate but more visual statement, you're pulling more light through the lens than actually exists (and breaking the laws of physics, but, hey, laws are meant to be broken, aren't they?)

You pull a film when there is too much light to use the aperture and shutter speed you want (e.g. you want a 10 second exposure time to smooth the waves on a beach at mid day in summer with a cloudless sky and use f/1.2 to minimise the depth of field to enhance the wavefront). You're attempting to reduce the negative density from a compete black. And using the same inaccurate statement, you're pulling light away because you haven't got a neutral density filter....

***********************

Now skip the rest to avoid confusion :)


Or, you do the same thing (increase or decrease the development time with a corresponding change in exposure) to increase or decrease the contrast of the negative for printing purposes. That falls under the Zone System.

At the end of the day, forget the terms. You increase the development and hope to get something out of an underexposed negative, or you cut development in the hope of salvaging gross overexposure (which arguably you'd achieve better with a reducer (look up Farmer's reducer, but this opens a whole new area). Underexposure, if deliberate, is achieved by using a higher film speed than the film actually has.

And if you want to get really complex, just remember that film speeds are determined scientifically where every variable is controlled by the ISO standard to give a negative where the image starts to appear at a given density above base + fog (definition: film bases are not 100% transmissive; they cut some light; all developers produce some development even where no light has fallen - that's chemical fogging). Change the developer, change the temperature (even if you use the same 68 degrees, does your thermometer exactly agree with the standard one?), change the agitation, change the tank size/type which would affect the flow, change the time (did you stop development at exactly the same time as the standard, use a stop bath or not?), did you pre soak which would affect developer take up initially? These are reasons why you may wish to deviate from the manufacturer's rating, and that's all before we get into the need of the enlarger types for the optimum contrast in the negative (determined by the development (and developer!)).
 
Last edited:
I should have listened and understood when you said skip the rest. LOL
 
Barney said:
...this usually resulted in dark negatives hence my exploration of varying my options.
Click to expand...
When you write "dark" do you mean dense? If so, you will get brighter prints. This is the key to understanding film work.

A dense negative will tend to show more grain, simply because there are more developed grains to show and what you see as grain is in fact the boundary between clumps of grain. This is why "solvent developers were invented, to reduce the boundary effect. If less grain is your goal, look at "soft working" solvent developers and experiment with reducing the development times. Typical reductions might be 10% of the instruction sheet time.

If by "dark" you mean the prints are not bright enough, increase the time in the developer, to make the negative more dense.
Barney said:
Where are you obtaining the instruction sheets for the developers?
Click to expand...
I always used the instruction sheets that came with the bottles and found that worked well for my needs.

For those of us who grew up in an analogue world, the "start by reading the instructions" approach was the default but we also knew that there were no absolute rights and wrongs. Instead, we learned that it was up to us to find the compromises that suited us. For those imbued with the digital approach, it is hard to think other than in terms of "yes and no", which never really fit well with the analogue universe.
 
Last edited:
Wayne's images seem to have improved, but to my eyes his earlier efforts were underexposed and underdeveloped, but a lot depends on any post processing that could have created the image looking like that. So, I'm wondering if you are right Andrew, and he has it back to front.
 
StephenM said:
Wayne's images seem to have improved, but to my eyes his earlier efforts were underexposed and underdeveloped, but a lot depends on any post processing that could have created the image looking like that. So, I'm wondering if you are right Andrew, and he has it back to front.
Click to expand...
You should have said Stephen, feedback is important, especially as I am only as good as the advice that I have received here.
 
Barney said:
Thanks for trying to help Andrew, for my development times I have been using Film Dev app on recommendation here and this usually resulted in dark negatives hence my exploration of varying my options. Where are you obtaining the instruction sheets for the developers? I considered the instructions on the bottle, perhaps incorrectly, as generic guidelines which could be improved when modified for specific film types.

I am also a big fan of the acronym KISS and feel that is what I am trying to do, come up with the simplest solution!
Click to expand...
Have you tried the Massive Dev Chart website, or it's associated app, Wayne? It's a really good way to get development times for all manner of B&W films and developers, including for pushing / pulling the film. E.g. here's a big table showing development times for HP5+ in Rodinal at a wide range of ASA/ISO settings: https://www.digitaltruth.com/devcha...er=Rodinal&mdc=Search&TempUnits=C&TimeUnits=D

The app is really useful when developing film as it acts as a timer. Plus you can use it to modify (automatically or manually) the various factors involved in the process.
 
I have the app Nigel and it has mostly served as a timer, one of the films I prefer, so far, Kentmere 200, is not even on there.

Thanks to all for your simplistic explanations, I think I have got it, the phrase expose for the shadows and develop for the highlights is now working out as

Pulling the film and pushing the development

I hope for goodness sake, or I must be thicker than Ghandi's flip flop.
 
Barney said:
...the phrase expose for the shadows and develop for the highlights is now working out as

Pulling the film and pushing the development
Click to expand...
It might be easier to think of it as meter for the darkest shadow you want to see detail in and develop normally.

Then, when you print the image, expose for that darkest shadow and burn in the areas that are too bright to hold the detail you want, (This assumes that you're using monochrome film and printing yourself). More here...

 
Barney said:
Thanks to all for your simplistic explanations, I think I have got it, the phrase expose for the shadows and develop for the highlights is now working out as

Pulling the film and pushing the development
Click to expand...
Depends what you mean. Expose for the shadows - don't underexpose (which is pushing the film); develop for the highlights - don't overdevelop which increases contrast and can lose highlight detail. Pushing development combined with generous exposure will almost guarantee blown highlights.

Expose for the shadows etc. should take account of the subject brightness range. Should that fall outside the range that the film can handle, then exposure is critical, and normally you'd rate the film at a lower ISO to ensure shadow detail, and cut development time to save the highlights. Should the subject brightness range be small, it would be preferable to cut the exposure (move the shadows further down the characteristic curve) and increase development to increase the low contrast of the scene. This is easier if you use sheet film or have interchangeable backs.

If you are not using a darkroom to make your prints, for Black and white films I'd recommend downgrading film by half a stop and NEVER increasing development time. At least that's what I do, so I would say that, wouldn't I?
 
For colour neg film I usually do use an EI 1/3 or 2/3 less than box, but then get it devved as normal. Seems to give slightly richer results.
 
You must log in or register to reply here.
Back
Top