Easy DIY focus mask

[iamjulian]

I was going to buy a Bahtinov mask, they don't cost much and they work well, it's just that I like making stuff and I didn't want to wait for one to get delivered.

I couldn't be bothered to cut out all those little grooves so I saw someone saying they were using a Y shaped stick.  I think they called it a Lord mask.  It got me thinking that maybe other shapes would work.  I had a few scraps of wood laying about so I made this thinking it may work.  It does.  On the camera live view (in Astrophotography Tool) it didn't look hopeful.  I was using a 2nd magnitude star and there were no obvious diffraction spikes.  So I switched to a quick 5 second shot viewed at 1:1 and got the image on the right.  That was as focused as I had been able to get it using liveview without the mask.  Slight change, 5 second image, slight change, 5 second image, etc.  In 30 seconds I had the image on the left without using liveview and sending the sensor temperature high.  I'd post instructions on how to make it but well, it's three sticks and a bolt   Someone's probably already made something identical, but if not, let's call it the 3 sticks mask.

Happy focusing everyone.

[Chriske]

Clever...!!!

[knobby]

An admin should make this a 'sticky'

[Stub Mandrel]

Some one will CNC one out of aluminium, anodise it green and sell it for £50. Of course it will work far better