After reading about the Bahtinov mask, I thought I'd sit down and make one to replace my Hartmann mask. It's not that the Hartmann mask wasn't working - it has been a great help in focusing. I just needed something that would give me an idea of which way I needed to move the focuser to get to an in-focus image.
Anyway, after a couple of nights of sitting with a piece of cardboard and a craft knife, electrical tape and a template from the web, I finally made my Bahtinov mask for my 8" newt. When I showed it to my eldest son all I got was "It looks a bit rough dad...". Yeh, thanks for that!!
Anyway last night I tired it out and guess what, rough or not rough it worked a treat! And it was so much easier deciding when the horizontal line was between the two diagonal ones rather than deciding when three triangles were overlaying.
So there you have it, for someone who doesn't have the luxury of live-view on their camera, I give a big thumbs up to Mr. Bahtinov and his wonderful mask!