Hi everyone :)

I am wondering who use a polarizer here? I just got one to protect the lens of my new sigma zoom but I am not sure how it works. I have the feeling the photos are darker and also it makes the shutter speed slower (because it's darker).
Should it be used mostly for taking photos of clouds or landscape? How do you use it?
I will post some photos taken with and without polarizer.
For those who don't know what a polarizer is, here's a link :)
http://www.cs.mtu.edu/~shene/DigiCam/User-Guide/filter/polarizer.html
I guess I will still have to buy a neutral UV filter to protect the lens without any side effect.

Olly

With my Pentax SLR, I put a polarizing filter on it and never took it off. I've been thinking of getting one for my Panasonic, if only to protect the lens. So you think a Neutral UV filter would be better?

The polarizer controls the reflections.The circular rotation conditions the polarization,so you have to find the right angle turning the filter
I don't use it because degrades the quality of the photo and the brightness to -2 stops,from the other hand increases the contrast,but i could do it on photoshop
It very useful when you have to take photos of a subject behind a glass,a boat with the reflection,a very bright sky etc
I believe that you would take better results at the summer with the bight sky :) Here in Greece many photographers use it during the summer

http://dpfwiw.com/polarizer.htm

For protection i would use the neutral UV :)

I used a polarizer on my SLR Canon eos 500N,but it has a TTL system and i hadn't to use the filter with rings

Ok just when I thought I was catching on here :) whats a TTL system? I need to compile all the knowledge I'm learning here to be ready to buy my camera. I guess its better to buy all the extras later? Boy I wish I could take one of you guys shopping with me when I buy mine.

Ok just when I thought I was catching on here :) whats a TTL system? I need to compile all the knowledge I'm learning here to be ready to buy my camera. I guess its better to buy all the extras later? Boy I wish I could take one of you guys shopping with me when I buy mine.

E-TTL is an exposure system that uses a brief pre-flash before the main flash to calculate the exposure index
To quote Canon:"the smarter E-TTL system captures the subject as a plane and ensures that images containing various colors and levels of reflection are captured accurately and optimally"
Olly could write more about E-TTL and A-TTL systems,the language doesn't help me to write more :rolleyes:

Thanks Sophia for the info I'm sure learning a lot here :)

Thank you Sophia for your explanation :)
Here are two photos taken using the polarizer:
http://www.megapixelworld.com/polarizer
It's not really a test, I didn't use a tripod etc but it shows the difference of colours at least :)
It is not great for action shots as it the speed is greatly reduced!

Olly there is something that i don't understand.Why on the second photo (with polarize)there are more "burn"whites? :confused: Maybe due to increasing contrast? :confused:
Did you post-proceeded the photo or it's as it turned out of the camera?

The two photos were taken with the polarizer, the second photo was taken with the polarizer at the maximum effect. I don't know why it burns more white - I didn't modify the photos. Maybe the contrast? It can also be because I took the photo from a slightly different angle (I was walking) and the sun?
Tomorrow will be a sunny day, at least it is announced as a sunny day ;) and I can do some tests using a tripod.