Does Polarising Glass have a Back & Front?

[russellsnr]

Hi, Quick question for those in the no.
I had a mishap with my Lee 105mm Polarising filter but as luck goes the glass is in one piece after it came out of the frame but the metal frame work got dented so it will not rotate smoothly and kept coming apart so and again luck came by I had an old Sigma none DG 105mm polariser so I have managed to get that apart so to use it for the Lee glass but does polarising glass have a back and a front or does it not matter?
Thanks
Russ

[dem]

If it is a linear polarizer, then it does not matter. If circular, then it does.

Stand in front of a mirror and look at the reflection of the polarizer while holding it in your hand right next to your eyes. Now flip it back to front. If you have not noticed any difference, then it is a linear polarizer.

[SuffolkGal]

Interesting, I thought only CPL worked with digital?

[NorthernFocus]

Interesting, I thought only CPL worked with digital?

CPL is necessary for AF to function. Has nothing to do with digital image capture.

[SuffolkGal]

CPL is necessary for AF to function. Has nothing to do with digital image capture.

Thanks, I didn't know that

[dem]

Interesting, I thought only CPL worked with digital?

Both linear and circular polarizers will work equally well on any mirrorless camera.

Only on (D)SLRs a linear polarizer may interfere with phase detection focusing and exposure metering.

[NorthernFocus]

Both linear and circular polarizers will work equally well on any mirrorless camera.

Only on (D)SLRs a linear polarizer may interfere with phase detection focusing and exposure metering.

That's a good point, Dem. Only phase detect AF is affected by linear polarizers. Contrast AF works fine.

[russellsnr]

Hi, Thank you for the replies people.
As I said in the OP had some bad luck with the Lee Pol but as luck goes I had the Sigma metal frame and got it right first go replacing the Lee glass into the Sigma frame and works fine.
Russ

[dem]

Only phase detect AF is affected by linear polarizers. Contrast AF works fine.

Not quite. Phase detection on mirrorless will still work fine as the PDAF pixels are located on the sensor, not in a separate unit hidden behind two mirrors as in DSLRs.