I finally got a chance to test my aluminium framed fishing line version...
:thum bsup:
It works great!
No messing with changing exposure settings on the camera either.
I did notice that when the image was out of focus there are a mess of diffraction spikes... maybe that's something to do with some fitting errors or the fact that I mis-strung my mask (so the angled lines are not in the same plane as the horizontals).
One thing I did notice though, is that the diffraction spike don't work the way I expected... out off focus the intersection moves along the horizontal spike and doesn't coincide with the star image... this seems to be different to what the others are doing. I think it is because I changed the direction of the strings to make the mask more structurally sound... I didn't think it would change the way it works like that.
Anyway... it works a treat!
Al.