Polarizer advice

Illah

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I got a polarizer a while back based on pretty much every website recommending one. Problem is I haven't yet found a situation where it's really made much of a difference. The basic technical usage is dead simple (i.e. angle from the sun affects polarization and yes, I know that I need to rotate it :) ). I think my problem is I'm not 'seeing' when and where it will come in handy. Any advice?

--Illah
 
It is probably most useful for reflections - assuming the correct angle of the light to your lens. It can also help darken skies when the light, again, is at the correct angle. You need hard light, of course, for any polarization to be visible. If the light is soft you won't get much help from it.

My problem with polarizers that I use a lot of wide angle lenses. So the field of view is wide enough that that correct angle only works for part of the frame. I wind up with polarized light filtered in part of the frame and not on other parts. It results in a gradient sky but from left to right or right to left.

You can probably tell I don't use them that much myself.
 
fmw said:
It is probably most useful for reflections - assuming the correct angle of the light to your lens. It can also help darken skies when the light, again, is at the correct angle. You need hard light, of course, for any polarization to be visible. If the light is soft you won't get much help from it.

My problem with polarizers that I use a lot of wide angle lenses. So the field of view is wide enough that that correct angle only works for part of the frame. I wind up with polarized light filtered in part of the frame and not on other parts. It results in a gradient sky but from left to right or right to left.

You can probably tell I don't use them that much myself.
Altitude also affects polarization. The lower in the atmosphere, the more dust swirling around, scattering light rays. Higher up there's less dust = less scattered light = more polarized light (from the sun). So when you use polarizer filters at altitude you get a stronger polarization effect.

Likewise you'll get much less of a polarization effect in downtown smog-ridden L.A. than you will a couple hundred miles away from that in the desert, where there's much cleaner air.
 
Well I'm in SF and shoot mostly on the shore (sea level) and I too use a lot of wide angle lenses. Oh well, at least I have it for those rare occasions...

--Illah
 
I use mine, whenever I'm outdoors and it's sunny. It's great for when there is water in the shot...because you can change how the reflection off of the water looks...effectively changing how the water looks.

Here is a shot where I adjusted the polarizer to cut the reflection on the water...so that I could see the bottom of the stream.
Russ-1Web.jpg
 
Illah said:
I got a polarizer a while back based on pretty much every website recommending one. Problem is I haven't yet found a situation where it's really made much of a difference. The basic technical usage is dead simple (i.e. angle from the sun affects polarization and yes, I know that I need to rotate it :) ). I think my problem is I'm not 'seeing' when and where it will come in handy. Any advice?

--Illah

Are you using a circular or linear polarizer? The circular polarizer I use with wide angle lenses, even something as wide as a 15mm non fisheye. I always see the effect. I usually use it to darken and make skies bluer. They will also make your images more saturated. Can you give us an example of a shot taken with and without? That would help us give you some better advice.
 
No shots in particular really, just overall I've only been able to get noticable results a handfull of times. I haven't used it *that* much but when I do I feel likes it's barely doing anything. For a minute I though I got a bad one :) I had to do a test just shooting randomly into the sky near sunset to be sure it was working.

It's a circular PL and typically used on a 17-50 lens on a DSLR (~24-75 actual). When I get around to ordering a step up ring I'll also use it on a 70-300 telephoto.

--Illah
 
i use a polarizer everytime i shoot outside. regardless. I also use a linear polarizer and its easier to notice the effect. If you rotate it one way, there no effect, but if you rotate it 90 degrees suddenly the sky gets bluer. (with a circular polarizer you dont see effect)
 
W.Smith said:
Altitude also affects polarization. The lower in the atmosphere, the more dust swirling around, scattering light rays. Higher up there's less dust = less scattered light = more polarized light (from the sun). So when you use polarizer filters at altitude you get a stronger polarization effect.

Likewise you'll get much less of a polarization effect in downtown smog-ridden L.A. than you will a couple hundred miles away from that in the desert, where there's much cleaner air.

When I lived in Colorado at 6000' altitude I never used a polarizer. It could darken the sky almost to black. It was an interesting but unrealistic effect. The skies at high altitude don't need any help.
 
fmw, you're right. Polarizers sometimes get over-used on skies that don't need it.

Illah, use your polarizer to:
1. Cut out reflections (in windows, or as in Big Mike's post)
2. Blue up & cut back exposure of the sky.

And, as you said, angle matters.
 
Illah said:
Well I'm in SF and shoot mostly on the shore (sea level)
It's not the altitude that is the decisive factor, the relative absence of light-scattering particles in the air (dust, smoke, smog, fog) IS.
So, in SF, you'll have a hard time polarizing anything in downtown city centre, where the air is terrible. But if you drive 10 miles to Bird Island on a sunny and windy day (from sea), you'll have nice clean air and fantastic polarization.
and I too use a lot of wide angle lenses.
Wide angle and polarization don't go together, alas.
So, if you want a polarizing effect anyway, you'll have to fake it in PP. With HDRI, and/or saturation. Or there's probably a whole lot of other editing approaches possible.
 

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