I need some help. I am new to the world of filters and am learning that there are so many to chose from for every situation. I recently bought a circular polarizer for my 24-85 afs lens and am curious if this can be used as an everyday filter; or are there certain times when I should not use it, or never use it. Any advice would be greatly appreciated. Also any suggestions for other must have filters would help too(xmas is coming). I mostly shoot landscapes and travel photos with an interest in human nature photos. Thanks in advance.
for everyday use I would recommend the UV-filter. It has very little effect on the pictures you're taking (filter factor is zero so it doesn't absorb light) and serves well as protection for your expensive 24-85 afs lens. Costs should be around $15 or something, maybe even cheaper.
Circular polarizers do absorb light and therefore might get you into trouble in low light situations.
From experience, don't mount the circular polarizer filter onto the UV filter as it might show on your pictures at 24mm. So if you buy a UV filter for everyday use and want to use your circular polarizer, de-mount the UV filter first and after that mount the circular polarizer.
Cir. polarizers are great. They saturate colors by reducing glare on non metallic surfaces-foilage,paintwork,and things like that. They can make a blue sky look a darker, deeper blue, strength of this effect depends on shooting angle in relation to the sun. But a cir. pol. won't help a nasty cloudy sky. As far as what filters you need, I bought a bunch and found out I hardly use most of them. A polarizer and an 81B or 81C warm up take care of 95% of my outdoor shooting needs. BTW, if you want reflection on water or glass, don't use a polarizer. They remove or reduce reflections well.
Circular polarizers work great to take out glare, as Bill500 stated. However, you will lose a couple of stops (not sure how much from manufacturer to manufacturer) when it is installed, thus you may need a tripod if using slower speed film or shooting with low light levels. Make sure you buy a high quality one from a manufacturer like Tiffen, Hoya, etc. The cheap ones will have poor or inconsistent coatings that may harm, rather than help an image.
The key to using the circular polarizing filter is to make sure the sun is somewhere to your left or right, otherwise you will get no/very little effect with the filter (nice blue sky vs. washed out sky). Turn the outer ring and "see" what effect it has on the sky or reflective surface (again, non-metallic). You should see glare/reflections disappear. If not, reposition yourself to have the sun at the 3 or 9 o'clock position to the camera (off left or right shoulder). Be aware that too much polarizing will make the sky deep blue or purpleish, which will make the picture appear fake/digitally edited. You just need to practice and get a feel for how much polarizing effect is right for a particular scene.
Sometimes, you have unanticipated effects of the filter. For example, I took a pic of my 9 month old son on the beach this fall. Nice close up, shallow depth of field, but got some of the lake in the frame. Lo and behold, with the polarizer on, there is minimal reflection from the lake and you can see the rocks beneath the water. That really added to the shot and made it more interesting. I just may keep this filter on whenever I take outdoor shots in brighter conditions (remember that you will lose stops with it on, so make sure you have enough natural light for hand-held shooting).
As for a UV filter, I don't use one. Ot is just another piece of glass in front of the film that can distort the image. You already have several elements in the way (called your lens) that degrade the picture ever so slightly. Just be careful with the len(es) and recap after each shot. You shouldn't have to worry about a scratched element if you are careful.
i actually meant any polarizer as it reduces the light ranging from 1.3 to 2 stops depending on the brand
from what i can understand, under bright conditions it can confuse the computer to assume different light values, as for matrix metering the computer needs to know the absolute light values of the subject to guess the subject and make appropriate exposure calculations
I think Rockwell has a theoretical point with no practical application. (I've been fairly blunt in the past about my mistrust about much of what he has to say, particularly when it comes to his overly subjective lens reviews). From a practical standpoint, the matrix meter is not fooled by a polarizer. And Rockwell's point really doesn't make sense to me anyway. Consider a field of snow and a single tree as primary subject with big blue sky above. Sure the polarizer will darken the snow a bit, but it will darken everything. There is no reason to expect that the matrix algorythm doesn't take this into account and expose the snow properly. Rockwell explains why it _doesn't_ work this way and I can't explain how it does, but, consider this uncorrected image, shot on slide film with a polarizer on a 20mm Nikkor; for whatever its worth, the snow looks right to me. (Caveat: Windows gamma may render it a little darker than my mac gamma).
On wide angles, the amount of polarization can be uneven across the frame which results in noticeable darkening of one side of the picture. Also, a lot of times the sky is already a deep blue and extra polarization can result in very dark, almost black skies.