I dont see a difference when spinning my circular polarizer

[theregoesjb]

I bought a B+W (xs-pro KSM HTC) circular polarizer for my sigma 17-50 lens. I shoot with a canon t2i (550D). It screws on, and has a rotating element.

in general it looks fantastic, definitely better than my last polarizer. But in the field, I can never tell the difference of the image when I spin the thing. Looking at the image on the computer I can tell right away that sort of... directionality (?) of the polarizer. But looking on live view out in the sun, or looking through the view finder I feel like I cant tell.

Any tips for getting a handle on this while shooting?

 

[pendennis]

The view through a lens with a polarizer will vary depending on the viewing angle of the polarized light. Depending on the angle, there may be no difference (light to dark to light) in the view. Whether the polarizer is linear or circular, you should be able to see the scene darken. All my polarizers (linear or circular) are omni-directional. They turn 360 degrees. The only exception is the old Nikon polarizer which uses about 150 degrees of rotation. At times, the difference in light transmission will be minimal.

The circular polarizers were introduced because it was believed that the straight lines in the linear polarizers might be able to "fool" the auto focus sensors. There are a lot of arguments both ways. I converted over in the late 1980's, but I've also tried linear types on my DSLR's, and I haven't had a focus problem.

 

[480sparky]

Your LiveView image is so tiny you will have a hard time telling much difference.

Here's a good video:

 

[Dave442]

A tip I was told is to look at the ground and not the sky when rotating the CPL.

 

[Upadhyay]

Effect of a polarizing filter is more evident when it’s sunny and you have blue sky or you have very reflective nonmetallic surface. Look for the change in the saturation of blue sky or reflection on water, foliage etc.

 

[astroNikon]

I've always been able to see the difference in the sky & clouds when rotating my polarizers, but you do have to be at a angle to the sun.

Also, my B+W polarizer has a very small indent/notch at the top of the metal part so you know which is the top. If yours doesn't have it then just make a notch on it then you always now where the top of it is.

 

[dunfly]

One thing I learned while flats fishing is that if you tilt your head towards the sun, you will get the maximum polarizing effect from polarized sunglasses so you can see the fish better. I use this when photographing with a polarized filter. There is usually a dot on the top of the filter ring. Point this dot toward the sun and you should be pretty close to maximum effect. I have a hard time telling the difference through the viewfinder, so I use this technique.

 

[Gary A.]

Maybe you're turning it the wrong way ...

 

[Upadhyay]

For sky a simple trick is to form right angle between your index and thumb, then point your index finger to the sun. Now rotate your thumb while keeping your index finger directed towards the sun. The parts of the sky where your thumb points will have the maximum degree of polarization.

 

[Low_Sky]

The view through a lens with a polarizer will vary depending on the viewing angle of the polarized light. Depending on the angle, there may be no difference (light to dark to light) in the view. Whether the polarizer is linear or circular, you should be able to see the scene darken. All my polarizers (linear or circular) are omni-directional. They turn 360 degrees. The only exception is the old Nikon polarizer which uses about 150 degrees of rotation. At times, the difference in light transmission will be minimal.

The circular polarizers were introduced because it was believed that the straight lines in the linear polarizers might be able to "fool" the auto focus sensors. There are a lot of arguments both ways. I converted over in the late 1980's, but I've also tried linear types on my DSLR's, and I haven't had a focus problem.

Post redacted for fake newsiness. Thanks Dunfly!

Sent from my iPhone using Tapatalk

 

[dunfly]

[QUOTE="Low_Sky, post: 3847092, member:
In photography, circular polarizer refers to a circle-shaped linear polarizer. Made into a circle so they can screw onto a lens without a rotating filter holder.

Whether round or square, if it goes on your camera it’s a linear polarizing filter, in terms of light modification.


Sent from my iPhone using Tapatalk[/QUOTE]

Are you saying that the only difference in a linear polarizer and a circular polarizer is the shape of the glass? If so, this is not correct. How do you explain a Schneider circular polarizer that is rectangular in shape. A circular polarizer does not refer to the shape of the filter. It refers to a two stage polarizer that consists of an initial linear polarizing glass in front of a quarter wave plate that converts the straight line linear polarized light to a circularly polarize light. The linear polarizer is the portion of the filter that turns and the stationary portion of the filter is the quart wave plate.

 

[Low_Sky]

[QUOTE="Low_Sky, post: 3847092, member:
In photography, circular polarizer refers to a circle-shaped linear polarizer. Made into a circle so they can screw onto a lens without a rotating filter holder.

Whether round or square, if it goes on your camera it’s a linear polarizing filter, in terms of light modification.


Sent from my iPhone using Tapatalk

Are you saying that the only difference in a linear polarizer and a circular polarizer is the shape of the glass? If so, this is not correct. How do you explain a Schneider circular polarizer that is rectangular in shape. A circular polarizer does not refer to the shape of the filter. It refers to a two stage polarizer that consists of an initial linear polarizing glass in front of a quarter wave plate that converts the straight line linear polarized light to a circularly polarize light. The linear polarizer is the portion of the filter that turns and the stationary portion of the filter is the quart wave plate.[/QUOTE]

Touche, I knew that was coming. This being the beginners forum, I didn't want to get off in the weeds on expensive true circular polarizers. I guess I over-simplified. If you're telling me that the $25 Tiffen circular polarizer that a lot of beginners go out and buy also has a quarter phase filter and passes circularly polarized light, then I thank you for the education because I had no idea.