Bhatinov Mask

[Stub Mandrel]

I doubt there is anything new about this, but it might help someone make one.

Print off a suitable template and sellotape to a plastic folder (ideally black) with no wrinkles.

Use metal rule and very sharp craft knife to cut out the holes.

Wrap 25mm wide ring of 4-6mm thick foam around end of scope and cut so very, very slightly short. Glue ends together with superglue (well away from scope). Ring should be an easy push fit on scope.

Fit ring and measure overall diameter of foam ring. Using a compass (or a plate) mark a ring a couple of mm smaller on mask and cut out.

With foam on scope carefully wrap a strip of duck/duct tape around it with ~5mm overlap below and about 10mm overlap above.

Remove from scope, cut lots of small nicks in the short overlap, and fold over neatly. Now make similar cuts in the long overlap.

Carefully push ring on scope - it should now be slightly tighter. Drop mask into centre being careful not to trap any 'fingers' of tape.

Go round the outside carefully smoothing down the tape one finger at a time.

Voila! One waterproof Bhatinov Mask.

[ronin]

Very nice but go on tell me why do you want a water proof one ? :confused5:

It is the water proof bit that has me scratching my head.  :icon_scratch:

:D

[Tinker1947]

Maybe if it had been described as dew proof it might have escaped the scrutiny net.....

[Stub Mandrel]

Well I had thought of making one out of card - but if it got caught in the rain... plus if it falls in the river, it will float. Also resistant to gamma rays, UV radiation, microwaves and plastic BBs, but not fireproof, alas.

[Tinker1947]

Well if its not fireproof, i don't want one, well done on the theory of how to make one.....

[Stub Mandrel]

OK this is a totally gratuitous shot, but I was struck by just how pretty it looks -and it proves that the Bhatinov Mask works!

So easy to use - anyone who doesn't have one of these must be

crazy. The star is Arcturus, not Vega, a dead easy target for the webcam.