Posted by Toby on 03/13/06 08:41

"Frankie" <frankieplus@optusnet.com.au> wrote in message
news:1141899708.959313.13940@i40g2000cwc.googlegroups.com...
>I just bought a new lens. The Canon 6.5x12..
>
> I want to put a UV filter on it to protect the lens and have 2 main
> questions.
>
> Does the filter go on the 82mm thread directly on the lens or is it
> better to put it on the
> 105mm thread on the lens hood? Which is best or doesn't it make any
> difference?
>
> Also, I tried screwing in a filter on the 82mm lens and it really
> doesn't screw in nicely, It's as if it needs some lubrication. It
> -does- screws in but squeeks as it does so and you can really hear the
> metal rubbing together, then I'm too scared to tighten it a bit more,
> is this normal? What could be wrong here? I tried it with a hoya filter
> that has an 82mm thread and now I'm thinking that maybe the tiny space
> between the threads are different?

Don't worry too much about the squeaking--it's what happens when aluminum
hits aluminum. Expensive filters often use brass, as there is the
possibility of thread binding with alumi-alumi, but almost all modern
filters are mounted in aluminum rings, and it usually isn't a big problem.

Directly on the lens is preferable for a couple of reasons--first the
filters are less expensive, and as Bill points out you have less problem
with possible ghost reflections. Also there is a problem of dust on the
filter--it is often visible the wide end at small apertures--the closer you
are to the front element of the lens the better for throwing it out of
focus.

Toby

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