Filters without a front thread are used generally for wide-angle lenses as to not cause any vignetting..

'I reject your reality and substitute my own' -Adam Savage..

Allen722 wrote:.

I have just bought a UVwithout front thread and the CPL with front thread (I think) and Ihope I did not buy the wrong ones!.

It would normally be the other way around. All lenses with a filter thread can carry one standard filter without problems (otherwise why have the thread?!) but if you have two filters stacked or even one thicker filter such as a conventional polariser, it is possible that the filter will intrude on the very edge of the field of view causing 'vignetting' - dark or cut-off corners. This only happens with very wide angle lenses, and by no means all of them. Also, it is generally less of an issue with digital cameras because very few of them see the entire field of view of the lens..

To combat the problem, 'thin' filters are sold, and some of them have no front thread in order to be as thin as possible..

Stacking filters is a bad idea because it reduces image quality. Only do it if you have to...

Thank you guys!.

One more questions though, would the lens cap fit on the both kind of filter?.

Allen..

Most lens caps clip into the filter threads, so the ones without the front threads wont hold a lens cap..

'I reject your reality and substitute my own' -Adam Savage..

Thanks again!.

Well then I hope the cap that comes with the filter is a nice one!.

Allen..

...that would do nicely. I have one on a thin filter and it works great..

I purchased mine from http://www.camerafilters.com.

They have both filters and lens caps. good luck!.

LucyU ZI owner!Olympus C30-20Zhttp://www.pbase.com/lucyFCAS Member #98, Oly Division'Photography is the art of seeing what others do not.'..