I have an Olympus EPL1 with two lenses: the micro 4/3rds 14-42mm and the 4/3rds 40-150mm. At the beach today, I could see the sea creatures in the rock pools but couldn't take a picture of them. The reason I could see them was because I was wearing polarised sunglasses. Sticking the sunglasses in front of the lens didn't work. A passing professor of physics told me that it was because my sunglasses are prescription glasses!
So I'm considering getting a polarising filter, but have absolutely no idea what to get or what to look for (I've never even used filters before, let alone thought about buying one). Reading around on the internet, I see that there are two types: circular and linear. How do I decide which to get?
I've also read that I probably shouldn't bother with a filter for the 14-42mm because the front of the lens rotates when it focusses. (This isn't true of the 40-150mm, I just checked.) As a first foray into the realm of filters, would I be really hampering myself by only getting a filter for the 40-150mm lens?
What's a reasonable price to pay for a filter? Given that I'm only dipping a toe in this particular water, I don't want to pay a great deal for something that might turn out to be not as useful as I thought, but I do want to give it a fair go. Looking on a certain website, named for a South American river, I see a circular polariser filter of the right size for my lens (\phi 58) with a RRP of 70UKP but on sale for 14UKP. Don't touch with a bargepole? Or reasonable for the experiment?
My most likely use would be shots through water, and scenery shots with the sun low on the horizon (happens a lot in Norway).