Metering thru a filter

[karrimor2004]

Hi all,

New to this site........

Need some advise from experts here....

This question is killing me.....

Do you meter thru a filter (eg:Red Filter) and shoot, or do you need to compensate by say 3 stops after metering thru the filter before shooting?

Is it essential to compensate to get the correct exposure?

Will not compensating results in as good as not using the red filter?

When compensating, which do you adjust? The exposure setting or the shutter speed, since in this case I am taking landscape and would like to maintain a small aperture size.

Sorry for the questions....hope to receive some advise soon.

Thanks!!!

[straightarm]

If it's a plain filter, like the red one in your example and yur camera has through the lens metering, I would meter throught the filter, i.e. with the filter on the lens, and then there is no need to apply any compensation.

If it's a camera that doesn't have a ttl metering, and the filter doesn't cover the meter sensor then yes you would need to apply some compensation.

If you need to apply compensation, it's your choice, you can vary, aperture, shutter speed or both. It depends on what's important to you. If you want lots of depth of field then you would have to adjust shutter speed, if you want ed to avoid a shutter speed that would result in camera shake then you might have to adjust the aperture.

[karrimor2004]

Hey thanks......

I own a Canon EOS SLR (film) and a point & shoot digicam (Canon S30), so I suppose I should meter thru the filter when I use my film cam and compensate when I use the digicam?

Hmm.........wonder if I should compensate for my S30 if I am using grad ND filter?

Or perhaps as a rule of the thumb, I should compensate for all filters used as long as they have a filter factor, when I use them on my S30?



Seems like I need more help..........

Appreciate any......thanks!

[Clemmie]

Actually, you've got it figured out there. With the EOS, meter thru the filter. With the S30, adjust for filter factor - which will vary with different filter types. Better filters will have some guidelines included in the package.

[Michael Fanelli]

Actually, you've got it figured out there. With the EOS, meter thru the filter. With the S30, adjust for filter factor - which will vary with different filter types. Better filters will have some guidelines included in the package.

Doesn't the S30 have TTL metering? It is rare to find a P&S that doesn't. If so, nothing extra has to be done.

[another view]

wonder if I should compensate for my S30 if I am using grad ND filter?

Set up the grad ND where you want it for the shot, and the camera should meter just fine. That filter would be used to lower the contrast of a scene (darken the bright areas so that you have a more even exposure between the bright and dark areas) and the metering should not require any additional adjustment. That's true of any filter and TTL (through the lens) metering - because light passes thru the filter before it's metered.

A filter factor could be added if you didn't have any light meter. For example, using the sunny 16 rule and having a filter that required a two stop exposure you'd use ISO100, 1/125 at f8 in bright sun instead of f16 and the same ISO and shutter speed. I usually just use a filter factor when planning exposure - if I wanted a slower shutter speed in bright sun then I'd think about a two stop ND or something...