On 25 Jun 2002 02:57:32 GMT, johnpkiss@aol.com (JohnPKiss) wrote:

>I have a Canon 300/2.8 and a 200/1.8
>Both use the 48mm "drop-in" filter.
>
>The filter holder accepts glass elements with a 43mm diameter (exactly).
>
>I would like to replace the glass in one of the holders, (the 200 came with a
>diffuser !)
>
>Does anyone have any experience as to which regular sized filter yields a 43mm
>glass element ??

Actually, the answer was obvious once I thought about it.
Since most filters use a retainer the same size as the
thread-mount size, and the glass must fit just inside this,
the glass in a 43mm filter will be just a tad shy of
43mm in diameter...