cheap ebay filters

Has anyone used these before

http://stores.ebay.co.uk/Camera-Partner-Centre_Polarizing-Filter_W0QQcolZ4QQdirZ1QQfsubZ4QQftidZ2QQtZkm

They look very cheap and that worries me. I have just purchased a Sigma 10-20 and I would like a circular polariser but I am poor. I also realise there is not point adding cheap glass on top of expensive glass but where can one get a decent priced 77mm circular polariser?

I would be leery of the quality - but who knows?

Where I have a problem with PL filters is on very wide angle lenses.

I never seem to get even coverage, as only part of the shot is at 90 degrees to the sun.

I've been so frustrated in the past that I seldom use them now. And I LOVE polarizers!

Cheers

Eric,
For polarising, I use a Kood P-style polariser and with the Cokin slimline adapter you should be fine at 77mm.

It's certainly easier having one polariser that fits all lenses through the P-filter system

(Think I bought it from www.srbfilm.co.uk Just checked and it's about £25 for a P-size circular Kood.)
Note that some on here have said that a LINEAR polariser works just fine with the Pentax AF system... but don't quote me

Matt

Try a polarising filter on your 10-20 before you buy as it can have some wierd affects esp at the wide end. I got my local jessops to let me go outside with one on and take a few shots and I didn't like the results esp. at 10mm. Being so big (77mm) it won't be cheap so make sure it's worth it.

Thanks Matt, I may look into that and see if it is cheaper and more flexible.

The ones on ebay look dangerously cheap.

And thanks for your advice MX veteran. May head into Jessops and see if they have one I can try on but last time I tried I think they said they had none available for testing and I would have to buy one!

Just bear in mind that you would be placing a cheapo £4.80 filter infront of £300 of glass - personally wouldn't risk cheap/unknown filters

simon