what's the reason to push film

Hello, I'm wondering what the reason is to push film. As an example, you can use Tri-X 400 exposed at 1600 and then push it two stops. How is this different than using 1600 film (I know, they don't make this anymore)? Do you get better grain or contrast?

The two reasons are (which may include one or other or both):

1. Low light and therefore need faster shutter speed to hand hold camera. Not necessary if camera is on a tripod.
2. Increase film contrast where the subject contrast is low. Can often be done in printing instead.

Avoid pushing wherever possible since it requires extra development which increases grain and can be particularly difficult to meter properly. And can also make printing very difficult when resulting film contrast is very high.

Some people seem to think there is kudos in claiming they push their film to very high speeds. Ask to see their resulting prints.

box ISO speed and "normal development" will give you normal contrast negative. That should be true for both ISO 400 film and ISO 1600 film. But pushing ISO 400 film to EI 1600 will usually give you high contrast negative unless subject is low contrast to start with.

hudson,

People used to buy the fastest film they could, but it was never fast enough.

This created a "look" and now people might push film because they like that look.

ISO 1000 film is still available. But if you want to go for the look, Kodak Tri-X pushed to 1600 will certainly still give it.

I personally steer clear of pushing because I prefer an aesthetic that includes shadow detail.

The conventional wisdom is to use a faster film rather than push a slower one. When you push film you lose shadow detail. Depending on the subject this can be important or not. I think that many people are too quick to think of pushing as the only solution. Even in low light situations there are tricks to avoid camera shake at slow shutter speeds. Of course there are situations where pushing is the only choice to get an image.

RobC said:

The two reasons are (which may include one or other or both):

1. Low light and therefore need faster shutter speed to hand hold camera. Not necessary if camera is on a tripod.
2. Increase film contrast where the subject contrast is low. Can often be done in printing instead.

Avoid pushing wherever possible since it requires extra development which increases grain and can be particularly difficult to meter properly. And can also make printing very difficult when resulting film contrast is very high.

Some people seem to think there is kudos in claiming they push their film to very high speeds. Ask to see their resulting prints.

box ISO speed and "normal development" will give you normal contrast negative. That should be true for both ISO 400 film and ISO 1600 film. But pushing ISO 400 film to EI 1600 will usually give you high contrast negative unless subject is low contrast to start with.

Click to expand...

+1

Gerald C Koch said:

The conventional wisdom is to use a faster film rather than push a slower one. When you push film you lose shadow detail. Depending on the subject this can be important or not. I think that many people are too quick to think of pushing as the only solution. Even in low light situations there are tricks to avoid camera shake at slow shutter speeds. Of course there are situations where pushing is the only choice to get an image.

Click to expand...

+1

Yes!

Winogrand and others pushed Tri-X @1200 to get 1/1000 on the street.

hudson said:

Hello, I'm wondering what the reason is to push film. As an example, you can use Tri-X 400 exposed at 1600 and then push it two stops. How is this different than using 1600 film (I know, they don't make this anymore)? Do you get better grain or contrast?

Click to expand...

Added development increases contrast in an attempt to improve printing of under-exposed negatives.

To get a higher shutter speed/narrower aperture...or to increase contrast.

I haven't shot 400 B&W film at 400 in years - always shoot at 800 or so. Honestly, the films are so good now that the change in grain is negligible to my eyes and the contrast uptick is welcome to my style.

Getting back to the original question, I believe hudson was trying to understand when, and for what reasons, one would "push" film.

Before that can be answered, it is necessary to understand what actually happens during development. If you "push" a 400ASA film to 1600ASA, i.e. two stops, you typically double the develoment time (multiplying it by about 1.4 for each stop you "push"). What happens when you do this is that the contrast of the resulting negatives increases. The shadow areas stay pretty much the same (so they're underexposed by two stops, compared to the plain old 400ASA exposure and development). Because of the increased contrast, however, the mid-tones and highlights get more pronounced - especially the highlights. The full "1600ASA" speed is really only achieved in the highlights.

So what you're doing is buying a higher film speed in the midlevel and high tones, at the cost of lost shadow detail (since the shadow areas don't respond to increased development), and coarser grain (always an effect of prolonged development). This can be useful at times - just as an example, think of photographing a stage performance where the actors are under spotlights. Pushing your film might enable you to hand-hold the camera, getting decent prints of the actors, at the cost of having them stand out against a surprisingly dark background.

You mostly don't want to make this trade-off, because the coarse-grained, high contrast, negatives are no fun to print.

Thanks everyone...this is all really neat. I like the idea of the shadows staying the same and getting greater contrast between the shadows and higher midtones and highlights, if I understand correctly.

Before I was unclear why use 400 ASA at 800 instead of just using 800. But, this is exactly what I always did with digital files...clipping the highlights, pushing up the mid-tones and losing some details in the shadows. With film, the additional benefit would be more grain...and I can't tell you how much I love film grain (in moderation, of course!)

I'm not sure taking 400 ASA up to 1600 would be good...too much and the image starts to become more like a cutout graphic and less like a photo. But 400 to 800 or 800 to 1600 sounds like a nice way to add some character to the film.

hudson said:

Thanks everyone...this is all really neat. I like the idea of the shadows staying the same and getting greater contrast between the shadows and higher midtones and highlights, if I understand correctly.

Before I was unclear why use 400 ASA at 800 instead of just using 800. But, this is exactly what I always did with digital files...clipping the highlights, pushing up the mid-tones and losing some details in the shadows. With film, the additional benefit would be more grain...and I can't tell you how much I love film grain (in moderation, of course!)

I'm not sure taking 400 ASA up to 1600 would be good...too much and the image starts to become more like a cutout graphic and less like a photo. But 400 to 800 or 800 to 1600 sounds like a nice way to add some character to the film.

Click to expand...

Careful!

To be pedantic, "pushing" film really only refers to the development stage - it means increasing development, and therefore contrast.

People often erroneously refer to "pushing" film, when they really mean a combination of two things: under-exposing the film, and then trying to compensate by increasing development.

If you under-expose the film, you lose shadow detail, which you (mostly) cannot retrieve by increasing development. All you can achieve by increasing the time is to make the contrast of the near shadows appear more attractive.

If you expose the film by metering at the ISO speed (i.e. you do not under-expose it), and then push the development, you will retain the shadow detail, and increase the contrast of everything. Your shadows will become more differentiated from the mid-tones, although you may very well lose highlight detail. With modern films though, much of the highlight detail may be retrievable with printing manipulations. And if you want the shadows to be dark enough to hide the details that are there, you can achieve that through printing controls.

In Zone System speak, increasing the development when shadows are correctly exposed results in expansion. That is a tool used to convert a low contrast scene into a regular contrast print, by way of adjusting the negative to match the characteristics of the printing paper.

You need to be particularly careful about analogizing digital with negative film behavior. Poorly exposed digital files tend to lose data in the highlights, while poorly exposed film negatives tend to lose image detail in the shadows.

Hi MattKing and thanks for the warning! It's a shame I'm using a photo lab to develop and am only just shooting film right now...I feel like I am missing half the craft and half the understanding. On the other hand, shooting film is turning out to be quite an involved feat in and of itself and I think I'm going to have to wait a bit before trying to locate a darkroom (or create one in a spare room).

Changing bag is all you need for negative development and with a daylight loader allowing using 1000 feet lengths of ex-cine. - normal film tank, and bathroom as well.
Heave drapes, night, enlarger and print tube for wet prints.

Get the first free enlarger you locate.

A darkroom is an awesome rabbit-hole. Start off processing your own B&W with a changing bag, tank, and chems. Pretty simple actually.

Instead of changing bag you can use a windowless room and stuff a towel under the door. It's much cheaper to develop your own b&w. It's also faster than sending to a lab. You can find cheap enlargers on craigslist and/or buy a pakon f135 scanner on ebay.


Sent from my iPhone using Tapatalk

hi hudson

sometimes you really don't need to change the way you process the film and you can
just add or subtract a stop of light when you take the photographs and process "normal"
without extra ( push ) or less ( pull ) development.
a couple of years ago someone asked about exposing a 400 film to 800 and processing normally
it was suggested you could over expose or under expose 1 stop and process normally
and it is stated by kodak that their film can do that ..
here are 2 sheets of film ( tmy2 and trix ) both processed for the same time at the same time
both exposed 1 after the other... i covered my lens with a card and exposed on side at 200 and other at 800
its not a perfect test, the film in both cases was expired and not fresh, and i didn't make prints but quick scans
but as you can tell both sides are passable and hold an image.
its often suggested that with a new camera, new film and new developer the user/photographer
take a few test rolls ,,, meter and bracket exposures and developing to decide what they want rate / expose their film at
so it fits his/her methods of work ... to test the meter ( sometimes they are inaccurate ) and to test shutters ( sometimes without a cla they can be "off " )
and how the developing end of the process works.


have fun
john