Circular polarizer question

[Jim Rice]

Hi folks. I recently acquired a Contax circular polarizer for use with my RTS with CZ primes. The polarizing effects seem to be VERY subtle compared with the B+H linear that I used when I was shooting in large format. Is this normal for a circular? I remember reading somewhere that polarizers can "go bad". Might this symptom be an indication of that? Any advice appreciated.

 

[pentaxuser]

My Hoya circular polariser never seems to have that much effect either until I look at the effect on the neg. Unfortunately I cannot compare it to a linear as I have never used one but until you develop and print the neg I wouldn't assume that your circular won't give you the same effect as the linear.

I have never heard of them going "bad" I am not sure what there is in a polariser to stop it working or wear out.


The only thing I would add is that when you get near to having an effect on the sky only a very small movement of the outer glass makes a big difference so it is easy to move it too little or too much at that point

pentaxuser.

 

[ROL]

I'm sure you already know this, but make certain the light conditions require polarizing. In bright sunshine, polarization is increasingly less effective the more it deviates from 90 degrees off the source.

 

[Kevin Kehler]

The effects of my linear polarizer is much more noticeable than the circular polarizer. Depending on the situation, I switch between the two to get what I want - however, ROL's point still stands.

 

[pentaxuser]

The effects of my linear polarizer is much more noticeable than the circular polarizer. Depending on the situation, I switch between the two to get what I want - however, ROL's point still stands.

Kevin, does this"noticeable to the eye" effect from the linear polariser translate into a more noticeable effect on the negative?

Thanks

pentaxuser

 

[Kevin Kehler]

Kevin, does this"noticeable to the eye" effect from the linear polariser translate into a more noticeable effect on the negative?

Thanks

pentaxuser

Yes - I find the effect more noticeable in the negatives and more pronounced when printing. There is times I like it, there are times it is too noticeable. It all depends on the image I am wanting to achieve as to which one I use - I would estimate the linear gives 1/3 of a stop more effect, maybe a 1/2 stop in very limited circumstances (by which I mean, the sky would be 1/3 of a stop darker than if I used a circular). However, I have never done a full test but for example, skies done with a linear needs less burning in than skies done with a circular polarizer.

 

[benjiboy]

I suggest you use the type of polarizer the camera manufacturer recommends in the manual, because if you use a linear polarizer instead of a circular one on a camera with a semi-transparent mirror and a beam splitter it will effect the TTL metering reading, especially the spot metering.

 

[Kevin Kehler]

Very good point Ben; I don't shoot any 35mm and as such, always hand-meter thus negating the meter's restrictions. I tend to forget this requirement for most people.

Yes, most cameras require a circular polarizer in order to properly meter. If you use a linear polarizer on a camera which meters through the lens, it may expose correctly (by chance) and it may not but most likely not.

 

[pentaxuser]

Thanks for that. Interesting that the linear delivers a great effect and as most cameras have the means of overriding the internal settings, a hand meter with a linear might be a worthwhile combo.

At the very least a trial with a linear to see what and how much of a detrimental effect it had on the in camera metering might be a worthwhile experiment

pentaxuser

 

[Jim Rice]

Thanks folks. I know that I will have to put up with a circular if I want to use the built-in meter on the RTS, but was wondering if I had somehow acquired a dud. If it continues to annoy me I will go the linear/hand held meter path.