Pushing film beyond ISO limits of camera

pharmboycu · Nov 17, 2011

Hi everyone--

I've searched for a thread on this but had no luck finding one. If one exists, I'd graciously accept a pointer towards it.

I was shooting B&W through my Canon A1 and Pentax K1000 in low, warm light in a coffee shop recently during an open mic night. The max my cameras' ISO dial would allow me to push was to 3200 but I really needed 6400.

So, assuming you have a film capable of being pushed to 6400 (or higher), is there a mathematical way to extrapolate and "push" film beyond the ISO range of the camera?

For instance, if I set the ISO at the max of 3200 and shoot at 1/250, this will intentionally underexpose the film in the setting described. Can I then develop as if the film were shot at 6400 to correct the underexposure? As in would shooting ISO 3200 and underexposing @ 1/250, then developing as if it were shot at 6400, produce an image equivalent to ISO 3200 at a correctly exposed 1/125?

Maybe I'm making this out to be harder than it really is, however, it's something I'm really trying to understand and would be grateful for the help.

Thank you all again--

John

daveandiputra · Nov 17, 2011

Hi,

pharmboycu said:
For instance, if I set the ISO at the max of 3200 and shoot at 1/250, this will intentionally underexpose the film in the setting described. Can I then develop as if the film were shot at 6400 to correct the underexposure? As in would shooting ISO 3200 and underexposing @ 1/250, then developing as if it were shot at 6400, produce an image equivalent to ISO 3200 at a correctly exposed 1/125?

The pushing is done in developing stage. So yes under exposing from your light meter at 3200 then developing it as 6400, will Give you the effect you're after.

Cheers,

Dave

Rol_Lei Nut · Nov 17, 2011

I *think* what you're saying is right, though the phraseology is a bit contorted...

1) To expose your film as ISO 6400 when your camera is set for ISO 3200, just close one stop or use a speed one faster than what your meter indicates.
(Meter says 1/125 f/2.0, you use 1/250 f/2.0 or 1/125 f/2.8)

2) To properly develop your film which been exposed as though it were ISO 6400, you need to "push" it by the necessary amount.

Mike Wilde · Nov 17, 2011

Experiment with pushing moderately for yourself before worrying about extremes.

And work on getting to the low light event early so you can get a seat up front to allow you to use a fast prime, like say a 50mm f/1.4, and still put a lot of what you want to show into the frame. Low light available light and zooms are not a good combitation. Pushing is not a majic bullet.

ntenny · Nov 17, 2011

6400 is one heck of a push for any film, in any developer. It can be done, of course, but expect your contrast, grain, and failure rate all to be extremely high!

I'd probably shoot these situations on manual, if possible by taking an incident reading in the "stage" area first rather than trusting the camera's meter. Uneven, dim, indoor lighting is about the worst situation possible for reflective meters. If getting to the performers' position for an incident reading isn't possible, maybe take three reflective readings to cover areas that to your eye look like the "light", "medium", and "dim" areas of the room, and then switch between them by eye while shooting.

You didn't mention your lenses, but I agree with Mike above: fast primes. A monopod, or failing that a strategic place to brace the camera, will buy you another stop or two in shutter speed. If you can possibly do it, more exposure is almost always going to work better than extreme pushing.

-NT

pharmboycu · Nov 17, 2011

Thanks everyone-- VERY good and sound advice here. I probably am making this harder than I need to. I could have gotten by with proper exposures at 3200, however, 1/60 sec. exposure (even with my 50mm f1.4 lens) is living a little close to "the edge" (so to speak) for my comfort level. I'd much more preferred to set the ISO to 6400, shoot at 1/120, then push-develop the film. My problem lies in that the cameras' ISO dials will only go as high as 3200. So I was trying to figure a way to fool either myself or the cameras into that.

I'm still trying to wrap my head around this-- if I want an exposure equivalent to 1/120 at ISO 6400-- but the camera will only reach ISO of 3200-- then I can set the ISO at 3200, shoot away at 1/240, then push-develop the film to ISO 6400.

I know it's not an ideal solution, but I'm trying to figure a way to cheat with the equipment I have rather than resort to the dig*#al camera and it's higher ISO capability.

Thanks everyone!

removed account4 · Nov 17, 2011

hi john

you are making it harder than it is (you're right! )
if you set your camera to 3200,
just shoot at 1 speed slower than your meter says ..
for example, if your meter says 1/125 ... shoot at 1/60 instead.
you might meter the stage ( just walk up there with your camera )
and see what it says .. if you trust your meter, it will mostly be telling
you what the dark room should be exposed at
chances are you don't need to push your film nearly as much as you think

have fun !
john

MattKing · Nov 17, 2011

John:

What you need to get a feel for is the fact that the meter in your camera isn't really necessarily connected to the rest of the process - it just happens to be at hand when you take a photograph.

So as jnanian (and others) have said, you use that meter to measure the lighting conditions, adjust the results to take into account that you will developing your film based on a "push" EI that you cannot set on the dial on the meter, and set your exposure settings to take into account the results.

Your film doesn't "know" what your meter was set for. It does "know" how much light it is exposed to, and does "know" how much development it is experiencing.

I am guessing that you may have come from a digital background, where "ISO" seems to be just one of the parameters that you can set on your camera to adjust how the camera's sensor and processor and software respond. Film doesn't really work that way - the ISO is actually set at the factory. With film, you can use a different EI when you use your meter, and then adjust your development to obtain the best compromise available, but you cannot change the actual sensitivity of the film.

j-dogg · Nov 18, 2011

I do remember my instructor mentioning shooting ISO 400 black and white and pushing it to 6400 in the development stage but adding some sort of chemical in the process so the grain still looks like 400. I believe it was pioneered by Indiana State University, I'll have to ask him the details.

steven_e007 · Nov 18, 2011

I've taken a lot of shots of rock groups in the past in sometimes very gloomy lighting...

This will make some proper photographers cringe, but my technique was this (for very low light)...

Stick in the fastest film you've got.

Put the camera on manual and forget metering (my cameras only ever have manual anyway).

Open the lens up as wide as it goes, because you need all the light you can get (Use fast primes!)

Set the shutter to the slowest speed you can hand hold. For a standard lens that would be 1/60s, for a 135mm tele (which I used a lot at gigs) it would be 1/125s (or 1/250 if I was being jostled by the crowd).

Take the picture.

Who cares what the exposure or film speed is? You can't get any more exposure - the lens doesn't go any bigger and any slower shutter speed you'll get camera shake - your on the limit, so that is your lot.
Or to look at it another way, if it is going to be underexposed, it is going to be underexposed, you can't do any more than you've done, so who cares how underexposed it was?

At a theatre in a play or show you might get a mixture of light and dark scenes so maybe try a reading if the light is steady enough - but at a rock gig, especially small clubs, it was usually dim or dimmer. Even at big events, constantly changing lighting and bold colours tend to fool meters anyway, so I'd rely on film latitude and luck.

The first time you develop the film you might want to do a clip test to see how much to push the film, but personally I'd just chuck everything in Microphen (if it was Black and White, I'd use the same method for colour) and see what I'd got.

Usually, I got something

I know not everyone will agree with this approach, but I think sometimes there is a place for meticulous technique (when everything is under your control and you are making a 'fine photograph') - and a time to wing it by the seat of your pants.

dnjl · Nov 18, 2011

To my knowledge, the A-1 has an insane ISO setting range of 6-12800.

removed account4 · Nov 18, 2011

hi steve

not crazy at all, great advice !

john
( who regularly shoots similar situations 1/15thS @ wide open )

pharmboycu · Nov 18, 2011

steven_e007 said:
I've taken a lot of shots of rock groups in the past in sometimes very gloomy lighting...

This will make some proper photographers cringe, but my technique was this (for very low light)...

Stick in the fastest film you've got.

Put the camera on manual and forget metering (my cameras only ever have manual anyway).

Open the lens up as wide as it goes, because you need all the light you can get (Use fast primes!)

Set the shutter to the slowest speed you can hand hold. For a standard lens that would be 1/60s, for a 135mm tele (which I used a lot at gigs) it would be 1/125s (or 1/250 if I was being jostled by the crowd).

Take the picture.

Who cares what the exposure or film speed is? You can't get any more exposure - the lens doesn't go any bigger and any slower shutter speed you'll get camera shake - your on the limit, so that is your lot.
Or to look at it another way, if it is going to be underexposed, it is going to be underexposed, you can't do any more than you've done, so who cares how underexposed it was?

At a theatre in a play or show you might get a mixture of light and dark scenes so maybe try a reading if the light is steady enough - but at a rock gig, especially small clubs, it was usually dim or dimmer. Even at big events, constantly changing lighting and bold colours tend to fool meters anyway, so I'd rely on film latitude and luck.

The first time you develop the film you might want to do a clip test to see how much to push the film, but personally I'd just chuck everything in Microphen (if it was Black and White, I'd use the same method for colour) and see what I'd got.

Usually, I got something

I know not everyone will agree with this approach, but I think sometimes there is a place for meticulous technique (when everything is under your control and you are making a 'fine photograph') - and a time to wing it by the seat of your pants.

Steve, that is GREAT advice. Thank you for kindly showing me the forest I was missing for looking too long at one tree. I'd never thought about doing things that way and I'll *definitely* try this the next time I go and just try to enjoy the experience rather than obsessing over the details.

Truthfully, I took one photography course in the 7th grade and put the cameras away until being given a digital camera many years later. Maybe that, as another poster suggested, has something to do with my difficulty in understanding ISO as relative rather than absolute?

As of yet, the only developer I've used is D76, so I will try to research Microphen and follow your advice. I'm interested in finding an economical, easy to use developer that works well for several types of B&W film so I've got a lot of reading to do on that subect (and how to do clip testing) as well.

Thank you ALL again for the great advice!

John

Pushing film beyond ISO limits of camera

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