Circular Polariser

[Rookies]

I have a cokin Circular Polariser at the moment as I have 3 different lens so i use it on all of them as I was given the adaptor rings for all my lens so i can fit the cokin holder on.

But dont think the Circular Polariser doing a good job am i right in thinking of getting one that goes onto the lens itself would be better than the cokin one?

Cheers
Andrew

[Brammers]

What's wrong with it? Can you post some pictures? It's really hard to diagnose things with comments like 'it's not doing a good job'

I've never heard any complaints about the Cokin and polarisers - if anything they're often better as they're oversized for the lens leading to less vignetting.

[stevegreen]

Also remember that you don't just stick the CP on, you need to rotate it to give the effect you are looking for.

[Rookies]

That the thing when i move it i dont see any changes to the pictures that why make me think it no good.

A mate got a Hoya Polariser and when he moves his you do see changes.

[Brammers]

Can you post pics? There's all kinds of reasons you might not be getting an effect - it really helps. It's very unlikely to be the fault of the polariser - you probably need a quick primer on some tecnhiques.

[Rookies]

Originally Posted by Brammers

Can you post pics? There's all kinds of reasons you might not be getting an effect - it really helps. It's very unlikely to be the fault of the polariser - you probably need a quick primer on some tecnhiques.

Before I add the picture I would like to say I cant understand why i dont see different effect when i move the polariser at all though I should do unless I am seeing somthing wrong? I have a UV protector on all lens and the cokin fits on to that. Should that effect the polariser? I just cant understand when I move it around I dont see any different in effect.

Here a picture

http://www.flickr.com/photos/12918935@N00/432589497/

[allymac123]

With that picture you'd be unlikely to see any significant effect. The only difference I'd expect with a properly adjusted CPL is that parts or the railings wouldn't be quite so reflective.

If you have a TFT monitor you should find that when you rotate the polariser, at one point in the 360 degree rotation, the screen will go totally black.

[Rookies]

Originally Posted by allymac123

With that picture you'd be unlikely to see any significant effect. The only difference I'd expect with a properly adjusted CPL is that parts or the railings wouldn't be quite so reflective.

If you have a TFT monitor you should find that when you rotate the polariser, at one point in the 360 degree rotation, the screen will go totally black.

I dont appear to get that at all to be honest

[allymac123]

That is weird then. Mine does it on 3 different monitors I have tried (2 laptops + 1 normal). When just holding it up to your eye and turning it does it not make a difference to anything?

[Rookies]

Originally Posted by allymac123

That is weird then. Mine does it on 3 different monitors I have tried (2 laptops + 1 normal). When just holding it up to your eye and turning it does it not make a difference to anything?

Not at all mate honestly. Are you using a cokin one? that goes into the Cokin Filter holder? I have it right at the front of the lens

[allymac123]

Nope just a cheap Fujiyama that I had for my old camera (have yet to get one for my Canon lens). I've tried it with another one aswell and it does the same thing. It seems to me that your Cokin isn't working then (I've never heard of a PL filter not working mind!). Another test is on a car in daylight-it should make a noticable difference to reflections. Where you place it has no effect whatsoever. As I say when testing it just hold it infront of one eye and turn it.

Don't know what else to suggest really.

[Rookies]

Originally Posted by allymac123

Nope just a cheap Fujiyama that I had for my old camera (have yet to get one for my Canon lens). I've tried it with another one aswell and it does the same thing. It seems to me that your Cokin isn't working then (I've never heard of a PL filter not working mind!). Another test is on a car in daylight-it should make a noticable difference to reflections. Where you place it has no effect whatsoever. As I say when testing it just hold it infront of one eye and turn it.

Don't know what else to suggest really.

So If I turn it in the lounge now with just my eye should I see somthing? Or is it best to do it outside when it sunny as it to be sunny for it to take effect? I read somewhere it works best 90 degree from the sun

[Brammers]

If you turn it in the lounge you're going to have to know where you're looking. Polarisers generally add contrast to scenes, especially blue skies, but their most noticable effect is how they deal with certain reflections.

Polarisers have greatest effect upon water (which is why it works with the sky - it cuts out the reflected light in the water vapour) and glass. They do not effect metallic reflections, or surfaces without reflections, such as carpet or matt paint. You may see the sheen taken off a glossy (say hospital paint!) wall.

Here's 2 very quick snapshots showing how the polariser effects my room.

This one's without the polariser in effective position (e.g. it's on the lens but not twisted to have an effect)



Reflections everywhere.

I then twisted the polariser to cut out the reflections on the glass:



Massive difference. However look at those shots again - although the diffence on the glass is highly obvious, the difference between the different walls and frames is far more subtle - only a slight increase in contrast which is probably down to the different exposures at this stupidly high ISO I used tbh :P

Do the test in your room with something similar (TV screen, phone screen) and let us know the results. As allymac said, I've never heard of a polariser not working either.