Megrez 72 + ccd = can't reach focus

[Gonzo]

Greetings all,

Would need some help please with what could be a user error.... I've received my QHY5L-II mono yesterday and thought about trying it on the Megrez 72 last night (between the clouds....)

Came across a problem, I can't reach focus at all

I have the crayford focuser pulled out, the Skywatcher field flattener and then the camera, despite all of that, I cannot reach focus.

I'm obviously doing something very wrong here. Would I be better off using the diagonal instead of using the flattener?

Is there something I've missed somewhere?

[robin-m]

Use the diagonal, I have a Meg 72 and a QHY5 that I use as a guidescope. It needs a diagonal in there to get enough backfocus.

Robin

[Gonzo]

Thanks Robin, do you use any extension tube on the QHY5?

[robin-m]

Nope, just a 2" to 1.5" reducer to fit the camera nose.

[Gonzo]

ok, I'll try your method, thanks again for the help.

[steppenwolf]

I too have this problem with the Megrez 72 - why must they concentrate on getting it on an aeroplane when they should be thinking about its use in the field? - I use one of these to resolve the problem.

[Gonzo]

I too have this problem with the Megrez 72 - why must they concentrate on getting it on an aeroplane when they should be thinking about its use in the field? - I use one of these to resolve the problem.

Thanks for the link, is it the 50 or the 80 mm you're using please?

[steppenwolf]

With my WO FR III which is a focal reducer/field flattener, I use the 50mm extension tube and that gives me a 12mm reading on the focus tube etching. Is it very, very sad that I know this? :grin: