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12/18/2003 03:11:48 PM · #1 |
| I've never used one. I'd like to learn a little bit about filters. |
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12/18/2003 03:14:33 PM · #2 |
| I'd like to know more myself. All I have used is some ND2 (neutral density) filters to knock out some light. |
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12/18/2003 03:22:43 PM · #3 |
Demo of what it does
Polarizer Demo
The physics behind it:
How it works
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12/18/2003 03:33:14 PM · #4 |
OK..from what I can see...this can do about the same as a really good ND filter? Can you adjust 2 polarizers to block almost all light, and take good quality long exposures during the daytime? Getting a photo like the one in this challenge??
//www.dpchallenge.com/challenge_vote_image.php?IMAGE_ID=50611
Message edited by author 2003-12-18 15:34:03. |
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12/18/2003 05:46:46 PM · #5 |
Originally posted by Truegsht:
OK..from what I can see...this can do about the same as a really good ND filter? Can you adjust 2 polarizers to block almost all light, and take good quality long exposures during the daytime? Getting a photo like the one in this challenge??
//www.dpchallenge.com/challenge_vote_image.php?IMAGE_ID=50611 |
No, it is quite different. A ND filter reduces ALL light. A polarizer selectively blocks un polarized light. Specifically, it is used to reduce/remove reflections from non-metal surfaces and to deepen the blue in a sky. Usually, a polarizer will reduce exposure only by about 2/3 stop.
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12/18/2003 06:05:39 PM · #6 |
Yes, this is possible: crossed polarizer are a standard way to easily control light intensty. |
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12/18/2003 07:30:40 PM · #7 |
Originally posted by Harz_Joerg:
Yes, this is possible: crossed polarizer are a standard way to easily control light intensty. |
It is certainly possible, but you need two filters, each of which have two layers of material. Much preferrable to use an ND filter, ONE layer of glass for the same job. Only not adjustable. I use only an ND8 (3 stops), since I only want an ND filter when a dramatic light reduction is required.
Message edited by author 2003-12-18 19:34:49.
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12/18/2003 07:59:43 PM · #8 |
I have a Cokin circular polarizer A series. When I look through the viewfinder and rotate it I hardly see any difference in shading. Are there different degrees of darkness? Or is it just that our eyes are not that sensitive to the change whereas the camera is?
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12/18/2003 08:04:12 PM · #9 |
Originally posted by bruchen:
I have a Cokin circular polarizer A series. When I look through the viewfinder and rotate it I hardly see any difference in shading. Are there different degrees of darkness? Or is it just that our eyes are not that sensitive to the change whereas the camera is? |
Your eyes should see the same thing as the camera. You won't see a big difference, except with skies and reflections. If the sun is in the west, try facing north or south, looking thru it at the sky and rotating it; you should see a noticeable change in the blue sky. Reflections off of non-metallic surfaces will be nearly cancelled at a certain rotation as well. This effect is most noticeable for reflections at low angles.
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12/18/2003 08:46:16 PM · #10 |
shoot at light reflected off water and then turn the polarizer, you'll see it. Most of these filters have a tick mark on the side. Most say point that tick mark 90 degrees from the sun (others 180 or right at the sun). I just turn mine till I see what I want.
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12/18/2003 11:28:02 PM · #11 |
| Get yourself a pair of polarized sunglasses, where 'em for a while, especially while driving in bright sunlight, and you'll see what it's all about. Best place to buy polarized sunglasses is at a fishing tackle store. |
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12/19/2003 05:04:39 AM · #12 |
Best trick is to get two polarizers, and rotate one relative to the other gradually. At 90 degrees they should block out all light completely - it's bizarre to see.
Ed
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12/19/2003 07:59:45 AM · #13 |
Originally posted by kirbic:
Originally posted by bruchen:
I have a Cokin circular polarizer A series. When I look through the viewfinder and rotate it I hardly see any difference in shading. Are there different degrees of darkness? Or is it just that our eyes are not that sensitive to the change whereas the camera is? |
Your eyes should see the same thing as the camera. You won't see a big difference, except with skies and reflections. If the sun is in the west, try facing north or south, looking thru it at the sky and rotating it; you should see a noticeable change in the blue sky. Reflections off of non-metallic surfaces will be nearly cancelled at a certain rotation as well. This effect is most noticeable for reflections at low angles. |
Here is a good example - try shooting a Christmas scene in a department store window on a sunny day. When rotating the polarizing filter, it is easy to see the desired effect - you can either see right into the window or just see the reflection of the glass. |
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12/19/2003 08:57:37 AM · #14 |
Originally posted by Harz_Joerg:
Yes, this is possible: crossed polarizer are a standard way to easily control light intensty. |
Remember that you need one circular and one straight polarizer to mount the two and obtain a ND like effect. |
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12/19/2003 09:01:42 AM · #15 |
Originally posted by dacrazyrn:
shoot at light reflected off water and then turn the polarizer, you'll see it. Most of these filters have a tick mark on the side. Most say point that tick mark 90 degrees from the sun (others 180 or right at the sun). I just turn mine till I see what I want. |
Wow, you have some filter to Nikon 5700... I´m interested in know what filter mount (diameter) and adaptor do you use in your camera. |
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