Weird polarizer?

TCampbell · Jan 10, 2013

A circular polarizer is really just a linear polarizer with a quarter-wave plate layered AFTER the polarizing layer. It's very important that the polarizer go on the camera in the correct way (polarizing layer is forward of the quarter-wave plate). If you flip the polarizer around backwards it shifts the colors through blue/violet to a yellow/gold. This is normal.

You can actually "buy" a blue/gold polarizer for special effects and it's just the same polarizer with the filter flipped.

With that said, there are also low quality polarizers which don't even do a good job polarizing when they're used correctly and some of them cut some wavelengths more than others -- which causes the filter to put a color-cast on the image (not good). Keep in mind, however, that a polarizer works best when the light is orthogonal to the lens axis. If the light is coming from mostly ahead of you or directly behind you then you wont notice much of a polarizing effect.

Try pointing the polarizer at a car window with the sun at a near 90º angle from where you're standing (e.g. if the sun is in the west then you should stand either north or south of the car... but you should not be on the east side or the west side.), then twist the filter and you should notice the reflections almost disappear completely and you can see the interior.

You'll never cancel 100% of the reflections... not even with a great polarizer. It'll just cut most of them.

unpopular · Jan 10, 2013

^^ no, I know you'll never cut all the reflections - I used to have a Heliopan.

This filter doesn't seem to block reflections as much as it blocks everything but blue reflections, it doesn't seem to polarize evenly across the spectrum. Just never ran into one with this weird blue-cast. I was not aware though of the yellow-blue thing, never occurred to look through one backwards! to me that is more interesting.

TCampbell · Jan 10, 2013

Here's a blue-gold by Singh-Ray: Singh-Ray Filters: Gold-N-Blue Polarizer

thetrue · Jan 10, 2013

Holy $HIT!!!!!!!!! $240 for the CHEAP one!!!!!!!!!

I was all in for 1/10 of that for the cpl that I'll use once a month, and it didn't really decrease sharpness all that much.

unpopular · Jan 11, 2013

Yeah, and that is not AT ALL the same effect I'm seeing with this filter. It's way more subtle.

Ray12 · Jan 17, 2013

I use an $80 polarizer several times a month when I have to do some commercial photography. I use it to cut down reflections on shiny objects...and my polarizer works absolutely great...as intended...with no color casts or shifts. The reflections just disappear!! Yes the 90 degree rule is gospel for maximum reflection null. If your angle is not correct...you will get less than maximum results. Yes...maybe you got specialty kind of filter it sounds like possibly. Go to a photography store and tell the person you are interested in a polarizer that works better than the one you have. They will likely pull one off the shelf and you can try yours and theirs side by side (as long as the store isnt busy).

For absolute maximum effect I have also purchased 20 by 20 inch sheets of clear polarizer material. I put these in front of my strobes or hot lights. I make sure they are oriented in the right direction by looking for the little arrow on the side of the plastic. Using polarized lights...together with a polarizing filter...gives me incredible reflection reduction capabilities on glass, plastic, artwork, jewelery, etc. What a difference I get with and without the setup!!! I love it when I get a good null...my images look so much more professional without all those hot light glints and reflections all over.

I use a Tiffen polarizer...I love it. No color casts here.

Cheers,

unpopular · Jan 17, 2013

I'll probably get another heliopan. They're pretty easy to find used for about $40.

thetrue · Jan 17, 2013

I like the cheapy one for fun stuff. It makes sunsets WAAAAAY more fun!

unpopular · Jan 17, 2013

Yeah, the color cast thing isn't necessarily a bad thing, it's just what it is. I need to get a spanner, while I do I'll order a step up ring to experiment ... someday.