Re: Center Filter

[Felix Collins <felixc@xxxxxxxxx>]

Thanks for the advice.  I won't be doing this for a while, as I don't
actually own any lenses that need center filter correction!  :-)

It seems there are two ideas knocking around here.  The one that Marshall
is describing below is a printing mask to correct for the lens.  What I
meant was actually making your own filters to go in front of the lens on
the camera.  This has been mentioned too.

If people have successfully made center weighted neutral coloured filters,
I wonder if there is anyone out there that has made gradient neutral
filters?  ie dark at the top and light at the bottom.  It seems to me that
commercial center and top to bottom gradient filters are horrendously
expensive for what they are.  If you could make you own it wouldn't matter
much if they weren't too durable because you could always replace them.

Felix

> In theory it should work fine.
> Take an evenly illuminated (white) wall and then create a
>negative (well, acutally a negative of a negative = a
>positive) of it to create the proper printing mask.
> Getting the proper denisty will take some work. In the
>enlarger you may wish to try to place it on the illumination
>side of the negative and slightly out of focus.
>Let us know how you do,
>Marshall