How to use polariser?

[panzerpunk]

Hi,

Recently bought a 77mm B+W Circular Polariser. I'm not sure how to use it buy I know the theory behind the polarising light and the angle of polarisation.

My question is, how does the polariser affects image quality? I heard it can give you warmer saturated colours but at which angle should it be?

Also, is it advisable to use a polariser when it is cloudy or in indoors? It makes the image pretty dark...

Thanks

[jdredd]

Originally Posted by panzerpunk Hi, Recently bought a 77mm B+W Circular Polariser. I'm not sure how to use it buy I know the theory behind the polarising light and the angle of polarisation. My question is, how does the polariser affects image quality? I heard it can give you warmer saturated colours but at which angle should it be? Also, is it advisable to use a polariser when it is cloudy or in indoors? It makes the image pretty dark... Thanks

polarises are normally used outdoors. use it to reduce reflection of water, and take the glare out of skies i.e. makes them a little bluer.

best way to use one, is when you are outdoors, just turn the polariser until you aer happy with the effect that you get.

one way that you can see how well it works, is go to a swimming pool where you ahve a lot of sunlight reflection. turn it slowly and you will see all the reflection dissapear.

[renewification]

It brings minus about -2.5 stops.. if you learn how to calculate aperture....so if ur shooting at f4 the polariser will make it f5.2? something like that.

[zcwnfx]

yup yup, turn the thing in front of the polarizer.

the polarizer has 2 pieces of filter stacked together. i think it have a effect of 2/3 fstop down.

i think it will make grass or trees greener also.

[lastboltnut]

So do up + your exposure to compensate?

Originally Posted by zcwnfx yup yup, turn the thing in front of the polarizer. the polarizer has 2 pieces of filter stacked together. i think it have a effect of 2/3 fstop down. i think it will make grass or trees greener also.

[renewification]

Originally Posted by lastboltnut So do up + your exposure to compensate?

plus ur exposure? Nope..just shoot as it is....just that ur shutter speed will suffer in that case. The polariser works as a ND filter too...

[catchlights]

Originally Posted by renewification It brings minus about -2.5 stops.. if you learn how to calculate aperture....so if ur shooting at f4 the polariser will make it f5.2? something like that.

What?
2½ stops down from f4 is between f8 and f11, so should be f9.5.

[catchlights]

Originally Posted by zcwnfx yup yup, turn the thing in front of the polarizer. the polarizer has 2 pieces of filter stacked together. i think it have a effect of 2/3 fstop down. i think it will make grass or trees greener also.

is just a pieces of polarizer glass having two ring, so it able to rotate.

to maximize the effect, it will cut down 2~2½ stops of light.

[Andy Ang]

Differences? Take a look yourself.

Without:


With

[ianpaice]

Nice sample pics to show the diff!

[catchlights]

Originally Posted by lastboltnut So do up + your exposure to compensate?

It depends,
let say you are shooting with auto or programme mode, the camera will compensate automatically, if you use manual TTL metering, the TTL metering will factor the light loss.

Unless you are shooting with manual mode and using hand held meter, need to open up the aperture or lower the shutter speed to compensate for the light loss.

[Andy Ang]

Spot on!

[bent]

is it difficult to use cpl to make skies bluer?

i read some articles like must have certain angle from the sun etc...like so cheam like that. any easier way?

[catchlights]

polariser

[lastboltnut]

Thanks catchlights for your explanation!

Originally Posted by catchlights It depends, let say you are shooting with auto or programme mode, the camera will compensate automatically, if you use manual TTL metering, the TTL metering will factor the light loss. Unless you are shooting with manual mode and using hand held meter, need to open up the aperture or lower the shutter speed to compensate for the light loss.