Variable & Interchangeable Focus Mask

[MG1]

I finally got around to cutting a few different focus mask shapes for testing in the frame I showed a few people up at Kielder in the Spring.

Here's a few photos....

The frames are simply laser cut from 3mm perspex, but then to get a sharper edge I used OHP acetate for the masks themselves then spray painted them.

Cutting new masks in thinner material is much much quicker and should allow lots of variations to be tested...if my scope wasn't in bits at the moment!

Might have to wait until autumn to get some comparisons done.

If anyone would like to suggest a rigourous method let me know.

Cheers,

Michael

[msinclairinork]

They look great Michael! Very profesional

Well done,

Michael

[MG1]

Cheers Michael, I had planned to finally put to bed the debate over Y 'vs' Bahtinov, 'vs' negative Y....but alas I decided to strip the mount apart for some tweaks so it'll have to wait a little.

I will also compare directly with the version that was just from 3mm perspex to see if the thinner material gives a sharper diffraction pattern. I'm thinking it will on the basis that scopes tend to use very thin material for the baffles.

...but i'm probably wrong....again