| Author | Thread |
|
|
05/01/2005 11:08:17 AM · #26 |
Clara is correct that it's not possible to make a polarizer that doesn't reduce light. The polarizer really does not polarize anything. It just rejects any light that is not polarized at or near the angle the filter is set at. As such, it rejects over half the light that falls on it, reducing exposure by about 1 stop (or a little more).
|
|
|
|
05/01/2005 11:13:36 AM · #27 |
when you thought ya knew something, and it turns out ya didn't know enough.
.......thanks DPC, I just learned a value lesson today.
Off to play.................
|
|
|
|
05/02/2005 08:20:53 AM · #28 |
Would it be possible to make a polarizer with clear glass instead of the dark glass that seems to be intentional tinted?
|
|
|
|
05/02/2005 08:22:15 AM · #29 |
Originally posted by coolhar:
Would it be possible to make a polarizer with clear glass instead of the dark glass that seems to be intentional tinted? |
No, the glass isn't tinted...it's just created in a way that 'filters' out light that's polarized in a certain direction. So whether you're into the photon theory or the wave theory...there's less light getting through.
I think that's kind of accurate, anyhow.
|
|
|
|
05/02/2005 08:35:38 AM · #30 |
I understand that there will be less light coming through. But all the polarizers I have used also change the color of the light at least slightly, and that might not always be desirable.
I first learned about polarization from using polarized sunglasses. Once I tried them I wouldn't have anything else, especially for driving. However, I have noticed that you can buy polarized sunglasses in differing shades and degrees of darkening. My question is could you make a polarizer, or a pair of polarized glasses, that would polarize the light without color changing tint or additional darkening added into the mix? If not, why not?
|
|
|
|
05/02/2005 08:47:36 AM · #31 |
Originally posted by coolhar:
I understand that there will be less light coming through. But all the polarizers I have used also change the color of the light at least slightly, and that might not always be desirable.
I first learned about polarization from using polarized sunglasses. Once I tried them I wouldn't have anything else, especially for driving. However, I have noticed that you can buy polarized sunglasses in differing shades and degrees of darkening. My question is could you make a polarizer, or a pair of polarized glasses, that would polarize the light without color changing tint or additional darkening added into the mix? If not, why not? |
They make warming polarizers that counter the effect of the color cast, but they do add a slight warmth to the image at the same time. You can correct digital color casts after the fact, or you can set a custom white balance prior to the shot.
|
|
|
|
05/02/2005 08:47:48 AM · #32 |
It's a good question you raise regarding color neutrality. AFAIK, high-quality polarizers are pretty close to neutral, but some color effects are inevitable. It's entirely possible that some color components may be more polarized than others, and thus might be removed more (or less) efficiently. Also, the polarizer's effect of reducing reflective glare can make colors appear darker and richer, but also can change them, since they lose the color component of the reflected glare.
With regard to light loss, it's a trade-off between effectiveness and loss. The more you restrict the polarization angle of what you pass, the more you reject, and thus the loss is greater. So, yoiu cna choose a more effective polarizer with greater loss, or a less effective one with less loss. |
|
|
|
05/02/2005 09:52:35 AM · #33 |
| What I always wonder is why it (sometimes) makes clouds or light colored sky look "dirty." Of course, I'm in LA so it's probably just making the smog more visible. |
|
Home -
Challenges -
Community -
League -
Photos -
Cameras -
Lenses -
Learn -
Help -
Terms of Use -
Privacy -
Top ^
DPChallenge, and website content and design, Copyright © 2001-2025 Challenging Technologies, LLC.
All digital photo copyrights belong to the photographers and may not be used without permission.
Current Server Time: 09/17/2025 02:11:24 AM EDT.
