Polarising filter help

[Louie]

Hi,

I impulse-bought a polarising filter the other day as I have seen them used with great effect but am having trouble working out the correct way to use it. Below are some pics I took today, one seemed okay but the rest look as though it was only working on one half of the picture.

Very uneven sky:


More uneven sky:


Same position but seems okay



Am I standing with the sun in the wrong place, do I not have the filter positioned correctly, what am I doing wrong??

Thanks,
Elena

[shakey]

If this a wide angle lens then this is normal appearance with polarising filters for sunny skys. I'd go into the science if I had half a brain.

[Louie]

Hmm, okay, I will have to research this further. Most of the pics I have seen previously have the lighter sky from top to bottom, not left to right like mine.

Why is it so different in the last two pics which are taken (from what I can recall) with the same technique?

[Oz_Beachside]

think someone told me they are most effective during each end of day (looks like midday from the shadow under the bridge).

[Marvin]

My polariser has the same effect. I think it depends on being a certain degree turned from the sun (I remember something about 45 degrees).

[iluxa]

It's perfectly ok from physics (optics) perspective. The poliarizing filter works better if the angle between the Sun, you and the optical axis is equal 90 degree. The polarizing filter is not working if you are shooting directly to the Sun or working a little if the Sun is right behind you. So because you are sooting at relatively wide angle different corners of your image have different angles with you and the Sun and therefore they have different degree of polarization which the polarization filter just "captures". It doesn't depend on filter brand, model, quality etc. It's pure physics. It depends on the Sun position in the sky, you and shooting subject. I have a lof of similar shots where different corners of images have different sky intensity.

Hope my explanation helps you.

[Louie]

Thanks guys, I think you are all on to something here!

Bruce, you are right - it was middayish. I was just doing some more reading up on this now which suggests, as you say, that midmorning is the best time.

Marvin, I will try various angles next time as well, do you mean with the sun 45 deg behind, or in front?
(I should do more research before I buy stuff!!)

Now, just need to wait for another sunny day in Melbourne when I'm not at work .............

[Louie]

Iluxa, thank you, that does help!
I think this is what Shakey was trying to tell me, I just didn't quite get it.

It would seem that the filter can be quite limited in its use if the scene is not 'facing' the right way. I still like it though

[iluxa]

It would seem that the filter can be quite limited in its use if the scene is not 'facing' the right way.

Not really. Well, you have a few options:
a) use ND Grad filter to correct it during shooting.
b) correct this in PhotoShop during post process using layer masks.
c) leave it as is.

[Louie]

There's those words again, 'layers' and 'masks', my next conquests.

Thanks for the help, everyone