Polarizing Filter

[MICKEY88]

The circular polarizers are made for digital use

technically they are made for autofocus, but work well on digital

 

[DizzyV6P]

Umm...DSLR's do autofocus except which you switch the lens button to Manual.

You can use a CP on any DSLR lense as long as its the same size There is no difference in that respect to film cameras. As someone mentioned, they're using the same one they used on their film camera. If you used to shoot a lot of film, there isn't a huge difference except for the ease in making adjustments on the fly. I know quite a few pro photogs who have made the switch with very little problems.

In the end, it comes down to your knowledge on how ISO, Aperture, F-stop relate to each other. There are some basic tenats of photography that never change regardless of film or digital. Digital simply makes it easier to achieve some results...the physics haven't changed. Light still works the same way with a DSLR. So if you're thinking of jumping....its not quite a jump, but merely a small step

 

[GrillMouster]

Yes, you can use a polarizer on a digital camera, but you didn't say whether you're using a DSLR or a point & shoot. Some camera manufacturers and third party companies produce adapters that allow you to use filters on a point & shoot. Check out lensmateonline if you're using a Canon p&s.

Circular polarizers are recommended for autofocus cameras, i.e., most, if not all, digital cameras. Some polarizers are labeled as "digital", but that's all hype. Any circular polizer will work, but stay away from the cheap ones. I've been satisfied with the high-end Hoya pro filters and I love the B+W filters.

 

[11290]

Just watch the type of lens that you use the polarizer on. Some of the DSLR lenses are "fixed" at the end while focusing and some rotate. If you set the polarizer with a fixed lens, no problems but if you set it with a rotating lens and then it refocuses, the polarizer may not have the correct orientation that you wanted.

It is possible to hold the polarizer and let the lens rotate but it is difficult to do.

 

[MICKEY88]

Umm...DSLR's do autofocus except which you switch the lens button to Manual.

ummmm yep I know that, I was responding to the comment that circular polarizers were made for digital

 

[LPZ_Stitch!]

Some camera manufacturers and third party companies produce adapters that allow you to use filters on a point & shoot. Check out lensmateonline if you're using a Canon p&s.

Circular polarizers are recommended for autofocus cameras, i.e., most, if not all, digital cameras.

Just a note ... *linear* polarizers work fine on P&S cameras (those which can accept filters, of course).

Circular polarizers are necessary for the 'phase detection' autofocusing method used by DSLRs, but they work on the 'contrast detection' autofocusing method on P&S cameras. too.

IIRC, some DSLRs now have an option for contrast detection which gets used when you're using the LiveView (or whatever the brand calls it) mode.

I don't know of any P&S cameras that use 'phase detection' autofocusing 'cause then you'd basically have a DSLR, in any case.

 

[tinkergrumpybuns]

Back before kids, thats even back before digital, I always used a pol. filter to get the nice crisp shots. Can you do this on a digital camera??

Correct me if I am wrong. I read recently somewhere , that b/c many cameras ( P&S as well as DSLR) have options to change the type of lighting
available, making polarizing lens more or less un -needed?
I am going to test this out tomorrow since it will be sunny as all get out here.
Maybe I got that from Scott Kelby's book?
Any thoughts on this?

 

[fitzperry]

Correct me if I am wrong. I read recently somewhere , that b/c many cameras ( P&S as well as DSLR) have options to change the type of lighting
available, making polarizing lens more or less un -needed?
I am going to test this out tomorrow since it will be sunny as all get out here.
Maybe I got that from Scott Kelby's book?
Any thoughts on this?

You might be thinking of colored filters, like warming filters. Changing the white balance can create a similar effect. In contrast, polarizers are intended to reduce glare and increase the intensity of blue skies--kind of like sunglasses for your camera lens. They are quite useful with a digital camera. I guess you can achieve that to some degree in post processing, but not without a lot of trouble, and the polarizer can probably do it better (at least better than I can).

 

[tinkergrumpybuns]

You might be thinking of colored filters, like warming filters. Changing the white balance can create a similar effect. In contrast, polarizers are intended to reduce glare and increase the intensity of blue skies--kind of like sunglasses for your camera lens. They are quite useful with a digital camera. I guess you can achieve that to some degree in post processing, but not without a lot of trouble, and the polarizer can probably do it better (at least better than I can).

Thanks, I wish I could remember where I had read this, and unscrew my brain from it. I just purchased a teleconverter and polarizing lens thru lensmate for my G7. Then I read the notations somewhere and thought, OH geez, Just blew money for nada!
So, can't wait to try it out before my trip.
Thanks

 

[DisOrBust]

I wish I had a DSLR but no just a p&S. I threw out my nikon film SLR by accident and have regretted everyday!!

 

[fitzperry]

Thanks, I wish I could remember where I had read this, and unscrew my brain from it. I just purchased a teleconverter and polarizing lens thru lensmate for my G7. Then I read the notations somewhere and thought, OH geez, Just blew money for nada!
So, can't wait to try it out before my trip.
Thanks

I bet you'll find it wasn't a waste of money. Have a great trip!

 

[GrillMouster]

I read recently somewhere that...polarizing lens more or less un -needed...

In Photohsop you can darken a sky, to mimick the effect of a polarizing filter. However, Photohsop cannot magically create image data that's not there. A polarizing filter does so much more than just darken skies. It makes folliage appear more lush, it cuts reflections from water, glass and other reflective, non-metallic, surfaces. It does all of this by filtering out scattered light. Without a polarizing filter, the glare is just a big, white blob in the image, and photohsop can't recover all the lost detail.

Think of it like this: let's say you're taking a picture of me, but I'm holding a white piece of paper in front of my face (representing glare). You can try retouching or erasing the paper in Photoshop, but doing so won't reveal the image of my face behind it; that information doesn't exit in the image. Using a polarizing filter is like making the paper invisible, so when you take the picture you can see me.

Besides, I'd rather take two seconds to screw on a filter than spend two hours selectively darkening skies and trying to minimize glare in several images in Photohshop.

 

[pjacobi]

It is possible to hold the polarizer and let the lens rotate but it is difficult to do.

I usually get a focus lock, then adjust the polarizer.

Even if the front lens does not rotate, the polarizer will always need to be adjusted for each scene.


-Paul

 

[MarkBarbieri]

Think of it like this: let's say you're taking a picture of me, but I'm holding a white piece of paper in front of my face (representing glare). You can try retouching or erasing the paper in Photoshop, but doing so won't reveal the image of my face behind it; that information doesn't exit in the image. Using a polarizing filter is like making the paper invisible, so when you take the picture you can see me.

Great analogy.

Just don't assume that a polarizer can work miracles. The effect varies from vary pronounced to very weak. If you are shooting with the sun directly ahead of or behind you, the effect is weak. If the sun is to your side, it's stronger.

 

[Groucho]

Correct me if I am wrong. I read recently somewhere , that b/c many cameras ( P&S as well as DSLR) have options to change the type of lighting
available, making polarizing lens more or less un -needed?
I am going to test this out tomorrow since it will be sunny as all get out here.
Maybe I got that from Scott Kelby's book?
Any thoughts on this?

You're thinking of "high dynamic range" mode, where the camera tries to do a better job of capturing highlights and dark areas. This is not the same as a polarizer, which only affects certain types of light - it just happens that it's often used to darken skies so that they aren't blown out.

But polarizers can also cut down on reflections in windows or on water, which a dynamic range enhancement on the camera itself cannot do.

Paul - why would you adjust the polarizer every time? When shooting outdoors, I figure out which position will give me a nice deep blue sky, then leave it there and don't change it again unless I am going to a different effect (reflections, for example.) As long as you're not flipping between landscape and portrait, you should be OK.

 

[tinkergrumpybuns]

Thanks for all the tips and wishes for a good trip. I'll probably have a few hundred photos to post.

 

[jann1033]

You're thinking of "high dynamic range" mode, where the camera tries to do a better job of capturing highlights and dark areas. This is not the same as a polarizer, which only affects certain types of light - it just happens that it's often used to darken skies so that they aren't blown out.

But polarizers can also cut down on reflections in windows or on water, which a dynamic range enhancement on the camera itself cannot do.

Paul - why would you adjust the polarizer every time? When shooting outdoors, I figure out which position will give me a nice deep blue sky, then leave it there and don't change it again unless I am going to a different effect (reflections, for example.) As long as you're not flipping between landscape and portrait, you should be OK.

i'm thinking maybe he is moving ie , in normal non disney world life i take a shot, walk take a shot walk so probably am not in the same exact location to the sun or it could be my obsessive compulsiveness just makes me redo it all the time, could be either set of circumstances or maybe both but i redo anytime i move

 

[lightingguy]

I love a polarizer on my XTi.

 

[mabas9395]

I thought the difference between a linear and circular polarizer was that the linear type was a pain in the rear because you had to rotate the filter so that the polarized light came in at the correct angle to the filter and that a circular one did away with that problem. And that you could just point and shoot and not worry about how the CPL was rotated (orientation to the sun is another question - but not mine, I think I got that one ).

But I was looking at some filters the other day and noticed that the CPL rotates too. After researching this for a bit, I noticed on another discussion board that a poster was told to rotate his CPL to maximize the effect.

Anyone care to enlighten me? Is there a right way to rotate a CPL?

 

[Code]

Linear and circular polarizers work the same way in terms of how they affect the image.. you still have to rotate a CP to achieve the right polarization based on the angle of the sun.

SLR cameras use polarizing beam splitters to split the light coming through the lens 3 ways.. viewfinder, metering sensor, and AF sensor. With a linear polarizer, you get a cross-polarizing effect in the beam splitters, and both metering and AF are fouled. A CP has an extra layer behind the polarizing layer that de-polarizes the light (though the image has already been changed by the polarizing layer) so there is no cross-polarization and the AF and metering work as they should.