Help needed if anyone can give some

[thetonyblair]

I had ordered a polarizing filter from 7dayshop and got it on saturday.
Its very odd but when I place the filter on the lens which is a 70-200mm 2.8L IS USM lens, I cannot get sharp focus.
My camera is a 5d MK2 and I have tried everything.
Beginning to think now that the filter may be defective.
Any thoughts anyone?

[czwotzit]

Re: Help needed if anyone can give some

It maybe a silly question but did you get a circular as opposed to a linear polarising filter as these are the ones that you should use for autofocus. Next query would be the make of filter.

Have you tried it on any other lens?
Is it a screw on filter or one for a holder such as cokin?

Andre

[thetonyblair]

Re: Help needed if anyone can give some

Its a screw filter and I mostly don't use auto focus.
I can have it focused on something @200mm and no matter what the aperture, everything is still out of focus.

[Muscat]

Re: Help needed if anyone can give some

Its a screw filter and I mostly don't use auto focus.
I can have it focused on something @200mm and no matter what the aperture, everything is still out of focus.

If you are trying to focus at 200mm I am not surprised you are having problems as the published minimum focus distance for this lens is 1.2m

[codachrome]

Re: Help needed if anyone can give some

Try Manual focus..if this works you have the wrong filter..

Peter

[thetonyblair]

Re: Help needed if anyone can give some

I didn't mean my focusing distance and I know the minimum distance is just over a meter or to be honest about 1.5 I've found.

Anyway, I'm sure it is the wrong kind of filter.
A single line becomes a double.
I'll take a photo and show you guys what I mean.
Really frustrating.

[Oggie]

Re: Help needed if anyone can give some

Was the filter very cheap? I "accidentally" got one ( came as a set with a UV for £10) and it behaved in a similar way.