Two Polarizing Filters = One Variable ND Filter?

[RacePhoto]

Polarized light is something that's simple in the basics, and as it turns out, very complex in the way it behaves. Thanks for all the explanations.

I wasn't doubting you about the two circulars, I was just making fun of the fact that I bought a second one last year, so I could block out more light and control it, and in fact I was just making one into a very expensive ND filter of sorts.

Delay Plate!

The effect of a filter on a light source, such as over the flood light, means the light is already polarized, so putting on a filter on the camera can change the effects. I was looking at small sheets and then attaching them to the flash, to reduce reflections. Just way too many variables and complications.

I have some polarized sun glasses. Some camera backs and LCDs become black and unreadable, which is problematic. However, wearing them and taking photos, someone can see one image, without the glare and get home to see, that the camera didn't see the same thing.

However in a pinch, I've taken a photo through the sun glasses, and it worked. Someone with a P&S can just hold the lens in front of the camera lens, and shoot at water, and not have the bright reflections.

I can't see why someone would buy a Linear filter, just to reduce the light, when a simple ND would be fine. The glare and reflections are already taken care of. In fact, it makes me wonder, do they still make linear polarizing filters?

 

[Helen B]

"I can't see why someone would buy a Linear filter, just to reduce the light, when a simple ND would be fine. The glare and reflections are already taken care of. In fact, it makes me wonder, do they still make linear polarizing filters?"

Yes, linear polarizers are still made, though they are not available in quite as many variations as circulars. There are still plenty of cameras that do not use beamsplitters. Most of my polarizers are linear.

I'm not sure what you mean by "The glare and reflections are already taken care of." I buy linear polarizers to cut down reflections, not to act as ND, so I share your puzzlement about why someone would buy a linear polarizer just to act as ND, unless it was as part of a variable ND filter.

Best,
Helen