Exposure Compensation

[Barney]

How does this work on a film camera?

Is it just a change to ISO or is there another mechanism at play?

 

[gramps]

ISO on a film camera is baked into the film selected.

 

[Barney]

ISO on a film camera is baked into the film selected.

For an effect I am looking for I need to pull the film, but will exposure compensation just push it back?

 

[Kevin Allan]

When an automatic exposure mode is used:

1. A positive exposure compensation will increase the exposure.
2. A negative exposure compensation will decrease the exposure.

You might use it in a situation where the built-in exposure meter will not give the result you seek. For example, a with a backlit subject you could use positive exposure compensation to increase the exposure on the subject, otherwise the bright background would "fool" the meter into underexposing the subject.

On a shot-by-shot basis, the same effect can be achieved by varing the ISO set on the camera (as Gramps says, this does not actually change the ISO of the film).

It is most likely to be of use when the camera has automatically set the ISO using the DX code, or when a user is not confident with manual exposure.

 

[FujiLove]

The ISO setting and exposure compensation have the same effect, they change the response of the meter, but it’s helpful to separate their use so you’re less likely to get confused:

Think of the ISO you set on the camera as being locked to how you will develop the film. So in your case you may be using a 400 speed film, but using it at ISO 200. To pull it, you would then develop it as though it was an ISO 200 film (pulled one stop).

The exposure compensation is used when taking each photo, I.e. not related to the development. For instance, if you went out in the snow, you may want to add one or two stops to the exposure compensation to make the snow white instead of muddy grey on the negatives.

 

[Barney]

The exposure compensation is used when taking each photo, I.e. not related to the development. For instance, if you went out in the snow, you may want to add one or two stops to the exposure compensation to make the snow white instead of muddy grey on the negatives.

Then what would you develop at?

 

[Nikon photographer]

Then what would you develop at?

At the ASA the film is rated at

 

[Ian Grant]

ISO on a film camera is baked into the film selected.

It is nor as simple as that. The EI (Exposure Index) you use is based on the combination of film and developer chosen, then the development time also affects contrast and density required. Ideally you do some tests to determine the best effective EI.

Essentially you expose for the shadows and develop for the highlights, some of us use or pay lip service to the Zone System.

When I used Tmax 100 I always shot it at 50EI, but Agfa APX100 (original) at 100EI, same development times same contrast.

Ian

 

[AndrewFlannigan]

It is nor as simple as that.

I knew that there was a very good reason why, after exposing and developing thousands of films (literally) I jumped to digital with a loud "hooray"!

 

[Nod]

How does this work on a film camera?

Is it just a change to ISO or is there another mechanism at play?

Depends how you want to do the EC. IIRC, I had the choice to change either shutter speed or aperture when dialling in the EC in P mode but the camera stuck with the set parameter in A(perture) or S(hutter) Priority in the other semi auto modes. In M(anual), I can't remember but that would just be dialling away from the user set settings.

 

[excalibur2]

ISO on a film camera is baked into the film selected.

depends on the camera......without checking all of my cameras, I can overide what the cameras says because of the barcode on the film cassette e.g. using an old 200 iSO cassette with FP4 100 iso from a film loader, I just adjust camera Iso to 100 iso.

 

[LeeRatters]

Depends very much on the camera.

I've had film cameras with an exposure compensation dial. On others you have to set a different ISO to trick the meter.

 

[Nod]

depends on the camera......without checking all of my cameras, I can overide what the cameras says because of the barcode on the film cassette e.g. using an old 200 iSO cassette with FP4 100 iso from a film loader, I just adjust camera Iso to 100 iso.

ISO changing/setting (DX) stickers are also available.

Worth a quick look.

 

[sk66]

At the ASA the film is rated at

Not for pushing or pulling. I.e. if ISO 400 is exposed as ISO 200 and then given standard development the result would be overexposure. That's why it's called pull processing; the development needs to be pulled down to accommodate the overexposure (i.e. process as 200)... unless you meant the ASA you rated it at; then yeah.

For an effect I am looking for I need to pull the film, but will exposure compensation just push it back?

Setting an EC is just a "lazy way" to compensate for metering error; i.e. a scene that doesn't meter as middle grey. You can do that manually with SS/Ap on a per image basis (i.e. drive the meter +/-), or set it as a "permanent correction" for the duration using EC with an automated exposure mode.

 

[StephenM]

For an effect I am looking for I need to pull the film, but will exposure compensation just push it back?

What effect?

If you pull the film (which I'm taking to mean reduce the development time) you'll get a lower contrast negative. But by and large (within reason) little loss in shadow detail and a thinner negative. Increasing the exposure will give a denser negative at the same contrast.

Exactly what will depend on yourchoice of developer.