should I buy a polarizer? the definitive answer

Canon EF 24-105mm f/4.0L IS

07/28/2007 01:56:54 PM · #1

Hi all: maybe the title is a bit pretentious, but I was trying to make a call to everybody who ask that question. And it's a question that usually appears in the forums.
I'm quite new on photography, my first shots were a pair of years ago or so, so I know nothing of the film era. And I knew nothing less than a year ago about polarizers. And that's the reason I make this thread, to make people realize the wellness of that filter.
The question is: "if I have Photoshop, why in the hell I need to expend my money in buying a filter? I have tons of them in PS". Here comes the answer. First a bit of talk, and then some examples.

1.- What is a polarizer?
We don't mind. Well, it's a kind of filter that only lets the polarized light go throught it. But we're not going to discuss here (at least not me) about what is "polarized light". "What the polarizer does is cut out from the lens any light that is "scattered" relative to its orientation. Only parallel light rays pass through" (Bear_Music dixit). Let's follow...

2.- What parts does it have and how it works?
Basically, it's made of a piece of glass, that once is fixed to the objective can rotate. The amount of polarizing will come from how much you rotate the polarizer and your position from souce of light.

3.- What is a polarizer used for?
We are arriving to the important part, and the one I can contribute a little bit from my experience. There are some situations in which a polarizer is your friend:

3a) To get rid of unwanted reflections on cristal or water (it's not useful in metallic surfaces). The maximum angle of polarizing is 30Âº or 40Âº. Now here begin the examples. All of them are unprocessed (except the last one that is overprocessed, LOL). Just saved as jpg from the RAW file. And all the pairs of shots have EXACTLY THE SAME apperture, shutter speed and iso. The image on the left doesn't use polarizer and the one on the right do use polarizer. Examples:

3b) To achieve a better result on the sky: the blue of the sky gets bluer, and darker. The result of these is that the clouds seem more white and brilliant. And other effect is that you can avoid that washed skies so boring (haven't you never received that "sky is washed" comment on DPC?) The best angle in this case is 90Âº from the sun. Example:

3c) The saturation of grass and other colours gets increased. Examples:

4.- Misuses of polarizer
Sometimes you must be careful when using polarizer. Depending on the light and orientation of the scene the effect can be too extreme. And sometimes, when using it with a extreme wide angle lens, some parts of the sky can look polarized and some others not. Another thing to consider with polarizers is that if you're using a lens that rotates when focusing, you must rotate polarizer AFTER you have focused. Finally, polarizer can reduce your exposure by a couple of stops, and maybe you need that light... Examples:

5.- Conclusion
Come on!!! Don't wait more before buying a polarizer. All in all, it's one of the best things I have bought in photography.

Sorry for the extension, but I hope it's useful for somebody.

Ã�lex.

Message edited by author 2007-07-30 13:10:34.

zeuszen

Canon EOS-1Ds Mark II

07/28/2007 02:06:56 PM · #2

â�¢ Good for shots benefitting from longer exposures, flowing water etc.
â�¢ To bring out texture, as of the fur and feathers of animals

dwterry

Canon EOS-1D Mark III

07/28/2007 02:16:20 PM · #3

Originally posted by alexgarcia:

Finally, polarizer takes down the exposition for a pair of diafragms, and maybe you need that light...

Probably a language translation issue, but what I think you meant here is that the polarizer can reduce your exposure by a couple of stops.

You're right about not needing filters much in the digital age. But the polarizer is a must have. You simply can't do, in post, what it does in front of the lens. Once the details are lost or blown out by unwanted reflections, you can never get them back.

Thanks for sharing.

P.S.
The other filter I might recommend would be the Neutral Density filter for when you want to slow down the shutter without increasing DOF. And the Graduated Neutral Density filter, for when you need to reduce the exposure in one part of the image more than another (such as the sky).

fotomann_forever

07/28/2007 02:21:15 PM · #4

Very good post and I agree. Polarizer and ND filters are still essential in the digital age. If you do any shooting outside, these filters should be in your bag.

Sony 24-70mm F4 Vario-Tessar T* FE OSS

07/28/2007 02:50:29 PM · #5

Originally posted by dwterry:

Probably a language translation issue, but what I think you meant here is that the polarizer can reduce your exposure by a couple of stops.

You're right. I'll have some more "language translation issues", LOL...

Thanks for the answers, folks. This is a thread I had in mind for some time.

Ã�lex.

FireBird

07/28/2007 02:59:19 PM · #6

Thanks for the explanation and examples. Next time will you take up the Scalvertizer filter.

Bear_Music

Samsung Galaxy S24 Ultra

07/28/2007 03:00:40 PM · #7

Great post!

To expand on (1) a bit, what the polarizer does is cut out from the lens any light that is "scattered" relative to its orientation. Only parallel light rays pass through. This is why it is so effective in enhancing saturation, especially on foliage; all those curvy shapes are scattering light in every which direction, and the polarizer eliminates all that and gives you clarity and saturation.

R.

darnok

Nikon D850

Nikon AF-S Nikkor 16-35 f/4 ED VR

07/28/2007 03:25:39 PM · #8

What is also worth mentioning is that a polariser will only cancel out reflections from non-metallic surfaces such as water, glass, plastic and foliage.

Nullix

Canon EOS-5D Mark III

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

07/28/2007 05:39:22 PM · #9

Here's a great tip and I came on it by accident. Buy yourself a pair of polarized sun glasses and wear them all the time. You'll really pick up on how to use them in photography.

I bought a polarizer a long time ago and didn't quite understand why to use them. I read about why online, but I never truly understood it.

Then I started wearing the polarized sunglasses and now I understand. Now, I'll have to find my polarizing filters.

It's pretty funny when I'm walking around and turning my head clockwise and counter-clockwise to view the effect/affect. I wonder if others watching think I'm crazy.

fotomann_forever

07/28/2007 05:41:10 PM · #10

Originally posted by Nullix:

I wonder if others watching think I'm crazy.

Yes

GeneralE

Canon PowerShot S3 IS

07/28/2007 05:42:34 PM · #11

Originally posted by Nullix:

Here's a great tip and I came on it by accident. Buy yourself a pair of polarized sun glasses and wear them all the time. You'll really pick up on how to use them in photography.

I've used mine by holding them in front of the lens -- works in a pinch.

hanneke

Canon EOS-5D Mark II

Nikon AF-S Nikkor 16-35 f/4 ED VR

07/28/2007 05:44:47 PM · #12

What about the thing that ALWAYS comes up when you're talking about any filter:

WHY should I put a $25 piece of glass (plastic?) in front of my superb glass?

darnok

Nikon D850

07/28/2007 05:50:59 PM · #13

Originally posted by biteme:

What about the thing that ALWAYS comes up when you're talking about any filter:

WHY should I put a $25 piece of glass (plastic?) in front of my superb glass?

That applies more with UV, which do nothing but degrade image quality. A polariser does something, so if you want/need the effect it's worth the slight loss in image quality.

hanneke

Canon EOS-5D Mark II

07/28/2007 05:52:09 PM · #14

Originally posted by Raziel:

Originally posted by biteme:
What about the thing that ALWAYS comes up when you're talking about any filter:

WHY should I put a $25 piece of glass (plastic?) in front of my superb glass?

That applies more with UV, which do nothing but degrade image quality. A polariser does something, so if you want/need the effect it's worth the slight loss in image quality.

Aah right, that was a UV filter.. sorry!

soup

Canon EOS-30D

07/28/2007 05:58:32 PM · #15

i do the same thing. and everyone thinks i'm crazy - to the point i am starting to believe them... ;} but be sure to take off the shades before looking through the viewfinder. two reasons...

1- you'll ruin the polarizing coating on the shades
2- you'll F'UP the effect of the filter.

Originally posted by Nullix:

It's pretty funny when I'm walking around and turning my head clockwise and counter-clockwise to view the effect/affect. I wonder if others watching think I'm crazy.

and if you're going to buy a polarizing filter buy one that glass wise is as good or better then the glass in the lens it's going to be used on... so to speak. if you can afford a $600 lens, buy a $100 polarizer...

Message edited by author 2007-07-28 17:59:53.

soup

Canon EOS-30D

07/28/2007 06:03:46 PM · #16

Nullix

Canon EOS-5D Mark III

07/28/2007 06:20:11 PM · #17

Originally posted by GeneralE:

Originally posted by Nullix:
Here's a great tip and I came on it by accident. Buy yourself a pair of polarized sun glasses and wear them all the time. You'll really pick up on how to use them in photography.

I've used mine by holding them in front of the lens -- works in a pinch.

That's a big pinch. That actually scares me since my glasses are pretty dirty.

I've thought about it. I might try it just to see what effect it has.

Tom

07/28/2007 08:35:13 PM · #18

Originally posted by biteme:

What about the thing that ALWAYS comes up when you're talking about any filter:

WHY should I put a $25 piece of glass (plastic?) in front of my superb glass?

Here's why: I was in (photography) class this past week and we all had our cameras out, and the front of my friend's $2,000 lens was smashed to bits. He obviously didn't know, because when I asked him what happened, he just laughed, and then had a heart attack when he actually saw it. Turns out that just the UV filter took the brunt of whatever smashed it, and the front of the lens didn't have a scratch on it.

Anyways... GREAT post, and thanks for sharing. B&H is about to get an order from me, thanks to you :)

07/29/2007 05:44:30 AM · #19

Originally posted by fir3bird:

Thanks for the explanation and examples. Next time will you take up the Scalvertizer filter.

If I knew how to use it be sure I will not share...LOL

@Bear_Music and Raziel: I've added your comments, Thanks.

Originally posted by fotomann_forever:

Originally posted by Nullix:
I wonder if others watching think I'm crazy.

Yes

I must say I agree.

Originally posted by Tom:

Anyways... GREAT post, and thanks for sharing. B&H is about to get an order from me, thanks to you :)

I'll ask B&H a discount in my next buy as comission...

surfdabbler

Canon EF-S 18-55mm f/3.5-5.6 II

07/29/2007 06:27:43 AM · #20

Originally posted by alexgarcia:

2.- What parts does it have and how it works?
Basically, it's made of two pieces of glass, one of them is fixed and the other one can rotate. The amount of polarizing will come from how much you rotate the polarizer and your position from souce of light.

Only one piece of glass. :) They generally have two rings, to allow the turning, but only one piece of glass.

Everything else you've said is great, with good simple explanations, and some good examples to back it up and show what it does. I also like the bad-uses section at the end. :)

As for the sunnies, I bought polarising sunnies before I realised how useful a PL filter is on the camera. My wife looks at me funny when I walk around with my head on the side (like

Nullix) to get a good sky colour. They are also very helpful to wear when you are out with the camera. A quick tip of the head will show you what angle the PL filter is best at, and as others have said, will teach you a lot about what PL filters do.

Message edited by author 2007-07-29 06:32:03.

surfdabbler

Canon EF-S 18-55mm f/3.5-5.6 II

07/29/2007 06:38:09 AM · #21

Oh one other point that people always ask - circular or linear? The answer is pretty much always circular. They do exactly the same thing from a photographic point of view, but linear polarisers (and sunglasses) will stuff up some autofocus/metering systems on SLRs. Circular ones are always fine.

(Yes, there is a good legitimate reason to get a linear polariser, but I won't complicate things by explaining it here, unless anyone asks. If it's your first PL filter, get a Circular PL.)

darnok

Nikon D850

Nikon AF-S Nikkor 16-35 f/4 ED VR

07/29/2007 06:45:43 AM · #22

Originally posted by surfdabbler:

A circular polariser consists of a linear polariser followed by an element than converts the linear polarisation of the light to circular polarisation. This is done for the autofocus system to work.

07/29/2007 06:49:46 AM · #23

You're right, surfdabbler. I've corrected from two to one piece of glass. Thanks.

About circular polarizers and linear...I've read everywhere on the web that linear doesn't work. But some photogs has told me that they work. I have one that I'm not sure if it's circular or linear, but I suspect is linear. And it work great for me. It's a B+W TOP POL.

Ã�lex.

surfdabbler