Linear versus Circular polarizer for cross-polarized lighting

I know the reason for using circular polarizer filters with

autofocus cameras, but I wonder whether it matters which filter I

use with my manual focus Mamiya RZ. In other words, is the

polarizing filter effect going to be the same for both filters? I am

also going to use Rosco polarizing sheets on my light sources.

I'm told this will give a "cross polarized" effect. My light sources

are tungsten hot lights.

If your Mamiya has no 'internal' meter to worry about in the studio,

the type of polarizer should have no effect on your images. But keep in mind that 'sunlight' and 'tungsten' are not quite the same light quality: you may need to experiment a bit to find out if the polarizer filter(s) you plan on using have much of an effect in the final image. You may want to keep a notebook handy and record your exposures for one roll and see what makes you happy.

Circular and Linear polarisers give a similar, but not identical effect. You do not need a circular polariser with your RZ, and in any event the polarising lighting gels for use on your lights are linear, so you will need to use a linear polariser on your camera.<br>Be aware though, that the heat from your lights will damage the polarisers very quickly.

Garry,

 

I'm interested to know what would happen if I use a circular

polarizer (since I already have one) on my camera and a linear

polarizing gel on my lights.

Thanks.

Linear and circulat polarizers DO have the same effect (at least insofar as any two polarizers are the same). A circular polarizer is in fact a linear polarizer (which does all the work as far as you and the film is concerned), followed by a 1/4 wave plate (which scrambles the resulting light just to make the metering system happy, but doesn't affect the way things "look", either to you or the film.

 

Circular polarizers are needed when you have a partially reflecting mirror (as do most AF SLRs). AF really has little to do with it. AF systems work fine with either type unless they use birefringent lenses in the AF sensors (this can happens as a result of stress in plastic lenses). It's metering that suffers most when you use a linear polarizer on a camera that needs a circular polarizer.

Thanks Bob. You just saved me $75.00 that I don't need to

spend on a linear polarizer!

 

(Not bad, become a Photo Net patron for a measly $25.00; save

$75. the first week.)

Certainly you don't need to change your camera polariser to make it work with your lighting gels, but it's a pity that you paid extra for the circular polariser in the first place when you don't need it.... I can't agree with Bob totally, because circular and linear polarisers do work in slightly different ways and both the degree of reflection suppression and the degree of saturation increase are type-dependant.