Weird Spatial Filter Effect...

[John Sonley]

Jem - regarding the rings you mentioned - I think they are called Airey Rings.
I recall that if they are symmetrical and circularly continuous around the central point, without breaks in their structure, that is indicative of a clean pinhole
BRgds

John

[Jem]

Thanks John

I've heard of those before, you'll be able to see 'first hand' exactly what I mean on Saturday.

Regards

Jem