polarizer-can't tell any difference when rotating it?

[cactusclay]

Anyone else have problems seeing a difference through the lens, when rotating the filter? I see the difference when I view it on the LCD, but not when looking through the viewfinder :rolleyes:

[SkipD]

What camera and what lens?

[cactusclay]

20D and 300D and all the lenses that take a 77mm and 58mm filters. Maybe it's my eyes, but I just can't seem to tell any difference when rotating these circular polarizers. I could see the difference with film cameras and linear polarizers, but not with these.

[SkipD]

I just tested my 20D with 24-70 f2.8 Canon lens and my Hoya UV-PL-CIR filter. I could definitely see the results of the polarization changes while rotating the filter and looking through the viewfinder.

When you say that you see the results on the LCD screen, do you mean that you're viewing the LCD after taking pictures with the polarizer rotated differently?

It might be possible that you are not looking at a scene that responds very much to changes in the position of the polarizing filter. Try looking at a sky with clouds and blue sky in the same view, but not directly towards the sun.

Something I noticed with my filter a while back. If I look backwards through the filter and rotate it, I don't see the changes that I see when I look from the side of the filter with the male threads (the way the camera "looks" through it).

[robertwgross]

In certain conditions of sky, you will not see any difference.

To see it best, try it with the sun in mid-afternoon. Starting with your back to the sun, turn right or left until your camera is facing 90 degrees from the sun direction. Now rotate the polarizer.

---Bob Gross---

[cactusclay]

Thanks Skip. I'll try that. I guess I was thinking there should be a mark or something. I see a slat on each side, which would lead me to believe that it may mark the horizon line, but maybe I'm not using it in a situation that I can tell a difference. I have an outside wedding in a couple of hours and I was going to give these a try, but maybe I'll hold off for awhile, till I figure it out. Thanks again for the help.

[cactusclay]

I just tested my 20D with 24-70 f2.8 Canon lens and my Hoya UV-PL-CIR filter. I could definitely see the results of the polarization changes while rotating the filter and looking through the viewfinder.

When you say that you see the results on the LCD screen, do you mean that you're viewing the LCD after taking pictures with the polarizer rotated differently?

It might be possible that you are not looking at a scene that responds very much to changes in the position of the polarizing filter. Try looking at a sky with clouds and blue sky in the same view, but not directly towards the sun.

Something I noticed with my filter a while back. If I look backwards through the filter and rotate it, I don't see the changes that I see when I look from the side of the filter with the male threads (the way the camera "looks" through it).I can see a somwhat nuetral density effect on the LCD screen with the filter on and it illiminates some reflections in a car nearby, but when I rotate the ring, I can't tell any difference, almost as if the whole thing was polarizing and if that's the case, why have a rotating ring?
:lol:

[fetching]

i feel really stupid....

I didn't know you had to rotate them. I wondered why it spun around after you screwed it on the camera. d'oh!

:o

Now that i've gotten that important detail out of the way, can anyone suggest a good maker of polarizing filters? what brand should i be looking for?


also, can someone explain to me how spinning works...like when i spin it and things start appearing lighter, where does the darkening go, and vice versa? if i don't spin it properly, would there be a demarcation line between polarized and not polarized? :shock:

*smacks head* :lol:

[cactusclay]

In certain conditions of sky, you will not see any difference.

To see it best, try it with the sun in mid-afternoon. Starting with your back to the sun, turn right or left until your camera is facing 90 degrees from the sun direction. Now rotate the polarizer.

---Bob Gross---
Thanks Bob, I'll have to wait for the clouds to go away I guess, it's sort of overcast here. I was thinking it would work on reflections now anyway though and I guess it does, but I just don't see the difference when I rotate it.

[fetching]

on luminous landscapes, he says:

One final thought, and that's with regard to exposure control. If your camera has a TTL metering system then compensation for the filter will be automatic. On a manually metered camera you'll need to open up about 1.5 stops. I say "about", because the exact amount will depend on the degree of polarization.

For this reason I tend to bracket critical shots taken with a polarizer, even if the camera has a TTL metering system. In this circumstance, as in many others, the right exposure isn't necessarily the best exposure.

so on my XT i don't have to do anything unless i want to bracket to be safe, right?

by manually metered, i'm assuming he means a camera that has no internal light meter.

[robertwgross]

Thanks Bob, I'll have to wait for the clouds to go away I guess, it's sort of overcast here. I was thinking it would work on reflections now anyway though and I guess it does, but I just don't see the difference when I rotate it.

Reflections, like on a water surface?

I find it works pretty good for that. By rotating the filter, you can make the reflections come and go with the rest of the scene unchanged.

---Bob Gross---

[robertwgross]

so on my XT i don't have to do anything unless i want to bracket to be safe, right?

Right.

by manually metered, i'm assuming he means a camera that has no internal light meter.

Most cameras have an internal light meter, but some users prefer to use an external light meter, perhaps a spot meter, for more accuracy to a particular spot in the scene. Since the polarizer (on the camera lens) is not affecting the external light meter (in the user's hand), then the user would need to apply a filter correction factor. However, for the average guy with one XT and using only internal metering, don't worry about it.

---Bob Gross---