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04-09-2019, 09:28 PM   #1
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Focal length and polarizers

Which focal lengths do you find that circular polarizers are best suited for outdoor photography?

Do you have a favorite focal length or range where you prefer to use CPs? A favorite lens?

Post some shots here, and list the gear you used.

04-10-2019, 05:06 AM - 3 Likes   #2
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Anything wider than roughly 30mm on full frame is likely to show gradients in the rendering of the sky, so even though you absolutely can use a polarizer at wider fields of views, just be aware of the effects.

There is no "best" focal length for polarizers, in my opinion. Go with what works to get the shot.
04-10-2019, 08:11 AM - 1 Like   #3
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bdery said it all. If clear sky is showing, beware of too wide a lens with a polarizer. A look through your viewfinder should show issues (which exist for linear polarizers as well). Polarizers can really emphasize a cloudy sky by darkening the blue background and they are quite useful at reducing some reflections (depending on what they are from and at what angle they are reflected).

Also be wary of auto windows which contain a plastic inner sheet (for shatter protection). These can induce rainbow or pattern effects when viewed with a polarizer. Shooting through such windows can be an issue.
04-10-2019, 08:53 AM - 1 Like   #4
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I'll also second bdery's comment.

Polarizers have their uses at all focal lengths for removing or enhancing reflections on water, windows, leaves, etc. They can enhance blue skies but their effects become problematic with wider angle lenses or tiled panoramas. Polarizers can also enhance rainbows but only at longer focal lengths because the orientation of the polarizer controls what part of the rainbow is intensified with the orthogonal parts of the arc made invisible.

04-10-2019, 11:22 AM - 1 Like   #5
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QuoteOriginally posted by jcdoss Quote
Which focal lengths do you find that circular polarizers are best suited for outdoor photography?

Do you have a favorite focal length or range where you prefer to use CPs? A favorite lens?

Post some shots here, and list the gear you used.
I use CPL on every lens including long lens. CPL makes picture warm and saturated. I like that effect. I rather use CPL instead of pushing saturation slider in PP.
04-10-2019, 02:32 PM - 1 Like   #6
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I like using polarizers mostly on my old K/M/A 50/55mm standard lenses. These lenses have round clip-on plastic hoods, so you just have to turn the hood to move the filter. No vignetting at the focal length either.

In my case I can use linear version on my older film cameras and use them on colour or b&w film for darkening sky, reflections, darkening water and so on.

This is a shot with a LPL & red filter to make the sky look like a 1930's horror film. (Fomapan R100 slide film)



Phil.

Last edited by gofour3; 04-10-2019 at 02:38 PM.
04-11-2019, 08:34 AM - 2 Likes   #7
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The image below is a multi-file stitch. When I took it, I used a polarizer because the glare from the midday sun was killing the color of the rocks, but look what has happened to the sky, and there is no totally satisfactory way to correct such a uniform expanse of color and make it look natural.
Attached Images
 
04-11-2019, 08:51 AM   #8
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Thanks for posting photos, guys! I hope this will become a photo thread for images with polarizers.
A question I've never considered before, since you brought up LPs, Phil. Are LPs stronger than CPs? What's the advantage? I'm aware of the disadvantages.

And here's one of my images...



Badlands in B/W
K-1, M35f2, B+W KSM circ polarizer

04-11-2019, 10:24 AM - 1 Like   #9
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QuoteOriginally posted by jcdoss Quote
Are LPs stronger than CPs? What's the advantage? I'm aware of the disadvantages.
No, they are not stronger. Polarization is a complex concept in optics, but basically the "polarizing" part of a CP and LP is the same, the CP has a second element which "rotates" part of the linearly polarized light so that it can be split again before being measured (it's more complex than that, but the basics are accurate).

I wrote an article about polarizers a few years ago, you might like it.

Last edited by bdery; 04-11-2019 at 12:56 PM.
04-11-2019, 10:48 AM   #10
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bdery, who do you think you are? Some kind of PhD in physics specializing in optics or something? ;-)
Thanks for the article link, I'll read it post haste!
04-11-2019, 10:49 AM   #11
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bdery, who do you think you are? Some kind of PhD in physics specializing in optics or something? ;-)
Thanks for the article link, I'll read it post haste!
04-11-2019, 12:56 PM - 1 Like   #12
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QuoteOriginally posted by jcdoss Quote
bdery, who do you think you are? Some kind of PhD in physics specializing in optics or something? ;-)
as a matter of fact...
04-12-2019, 09:46 AM   #13
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QuoteOriginally posted by jcdoss Quote
Which focal lengths do you find that circular polarizers are best suited for outdoor photography?

Do you have a favorite focal length or range where you prefer to use CPs? A favorite lens?

Post some shots here, and list the gear you used.
I find all of the focal lengths are best suited to polarizers.
As an aside, good quality linear polarizer from before the autofocus era work just fine on Pentax cameras as there is no beam splitter on the exposure meter. They can apparently foul up the AF sometimes, but Iíve never had it happen.
Pretty much, if you donít mind having to manual focus from time to time, a linear polarizer is fine.
04-14-2019, 01:53 PM   #14
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The Pentax LX needs to use a CPL for manual metering, as a linear will mess up the meter reading. If using the LX in "auto", then you can use either a CPL or LPL.

This is from my LX review:

A special half mirror was added to the LX to make the viewfinder brighter and easier to focus. This mirror is multi coated and acts like a polarizing filter, so if you use a linear polarizer and shoot in the manual mode you could get a messed up meter reading. However in auto (aperture priority) mode you can use either a CPL or LPL, as the half mirror flips up when the shutter button is pressed and the exposure metering is done off the film plane.

Phil.
04-14-2019, 03:40 PM - 1 Like   #15
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QuoteOriginally posted by gofour3 Quote
The Pentax LX needs to use a CPL for manual metering, as a linear will mess up the meter reading. If using the LX in "auto", then you can use either a CPL or LPL.

This is from my LX review:

A special half mirror was added to the LX to make the viewfinder brighter and easier to focus. This mirror is multi coated and acts like a polarizing filter, so if you use a linear polarizer and shoot in the manual mode you could get a messed up meter reading. However in auto (aperture priority) mode you can use either a CPL or LPL, as the half mirror flips up when the shutter button is pressed and the exposure metering is done off the film plane.

Phil.
True enough, that is the only Pentax SLR that doesn't meter off the screen.
I believe the OTF metering only works at slower speeds. I recall reading that above the sync speed, it took it's reading from the leading curtain up to the moment the button was pressed and that was the exposure you got. It was a cool feature, as it would adjust the exposure duration if light conditions changed during it.
I used the feature very successfully at a music awards show shortly after getting my LX.
I did a little gallery dedicated to the LX when I was maintaining the Pentax Users Gallery.
For the curious among us: https://pug.komkon.org/LX_Gallery/index.html
It looks terribly dated now. That was published in either July or August 2001.

Last edited by Wheatfield; 04-14-2019 at 03:50 PM.
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