When I use my uv filter on my telephoto of wide angle lens I get a slight halo effect. When I looked at it closely, it seems the inside of the wa or tele lens is being reflected in the uv filter. This does not happen when I use the uv filter on the built in lens.

I am useing Tiffen uv filters and "digital" wa/tele lenses. As these are "cheapies" I'm not reallly all that worried about it. I manely use the uv filter to protect a valuable lens. I was just wondering if there was something I can do to correct the problem.

It's not a good idea to but on a filter with any wide angle adaptor; there's usually a problem. However, sometimes you need to protect it from the elements.

Frank,

Presumably this is different for an actual WA lens (such as the Canon 3x for XL1)? Is it just adapters for which filters might be an issue?

Hoya make a thin UV with a (6 coatings) multicoating on both the inside and outside surface.

http://www.2filter.com/hoya/hoyauvsky01.html

Other than that a deeeeeeeeeeep matt box or lens hood with a wholloping great french flag ( the size of an elephants ear )

Yeah, this is common. I have a Tiffen UV protector on just my standard camera lens, and when the sun or lights are to the side or top, it also reflects the lens. I usually quickly remove it, if I need to get a shot and I get this flare....

Try this link for a clamp on hood with the flag

http://www.cavision.com/french_flag_for_3x3.htm

"Is it just adapters for which filters might be an issue?"

Yes, wide angle adaptors will have problems when you screw on any filter (vignetting), but a slim line filter would most likely be better, since the filter might be seated closer to the adaptor.

Thanks Frank. I guess I wouldn't need a slimline filter with the 3x itself, but it would be dumb to spend so much on a lens, and then risk the optical performance by skimping a few dollars buying an ordinary UV filter for protection.

When I get the 3x, I think I'll just splash out the extra for a slim filter.

I'd try it before you buy it. I spent good money on a Heliopan UV, slim line, for my MX300. It's no big whoop. I get reflections bouncing off the lens onto it---and that's with a lens hood on it! So try the filter before you buy it.

The link I supplied is for the heaviest multicoating on the market. As the name implies they are also thin mounts and thin glass.

There are articles on the effect of multicoating on the 2filter site as well as a chart showing which manufacturers offer coating and what the mounting rings are manufactured from. Brass is considered premium.

Heliopan, B+W and Hoya are the only manufactures that offer multi coating according to the following chart.
http://www.2filter.com/faq/facts.html

Kenko and marumi offer mono coating as do heliopan, B+W and Hoya. The Multi coating isn't much more. The thin mount and glass is about a 25% premium over the standard mount multi coat.

Joe,
I think what you have to ask yourself is why you're using the filter at all. If you're not shooting in a harsh environment just take it off.

I too didn't think I needed a protective filter until this:

http://www.dvinfo.net/conf/showthread.php?s=&threadid=8338

The hit always happens when you least expect it. In the referenced case, I had reason to expect flying flint.

But I've been at a school and had a student stick a pencil into the lens front 'just to see what would happen.' Fortunately the filter was in place because he used the eraser end of the pencil. He did indeed find out what would happen as his parents bought me a new $80 B&W filter.

For me, the filter never comes off. I'd rather shade the lens than lose it.

B+W makes an excellent coated UV protective filter that does not cause the bottom of a Coke bottle effect.