This should work..right?

[Yawning Angel]

Hello!

I'm moving from a dslr to a cooled cmos camera (asi1600mm pro). Now all the bits and bobs have arrived, it's time to put theory into practice and screw everything together

Question is, how does this look? I was a little vague on how the OAG's back focus is calculated, but this seemed to make sense. Since the photo, I've removed the 5mm spacer from the guide path, once I could actually grip to unscrew it :-)

My best way to test it would be trying to focus both in the daylight, but I won't to opportunity for a while yet

ZWO asi1600mm pro -> ZWO Mini EFW -> spacers -> ZWO OAG -> ZWO asi120mc-s (The build quality on the ZWO gear is impressive...instructions, less so!) All hanging off the back of an Evostar ED80 + 0.85 flattener

Thanks for looking!

and the number look like this:

[Jkulin]

1 hour ago, Yawning Angel said:

once I could actually grip to unscrew it :-)

I regularly have this problem despite coating the threads with graphite pencil dust, so I have resorted to putting two 1mm deep slots in the extension rings, then I get a thin blade in to unlock, works a treat and no frustration, I honestly can't understand why manufacturers of these expensive rings\Adapters and filters don't put an knurled pattern onto the outer surface. Where I have a large enough surface I drill two very fine 1mm deep holes on the face so that I can get a key to unlock.

[Yawning Angel]

John,

Neat tricks! I tried a few things from suggestions dotted about on SGL, including two training shoe soles! What worked in the end was warming it on a radiator then spraying the inner threaded part with the liquid from a can of air-duster to freeze it rapidly - unscrewed like it was loose all along :-)

[SteveA]

Well...yes it should work....but..

You have obviously spent some time measuring the spacings and that's a great way of approaching this. Of course until you test this out and establish if indeed you have enough inward travel to bring the components to focus you wont know. If it doesn't....we'll that's where the fun starts?

Steve

[Yawning Angel]

Thanks Steve, I’m hopeful! Looks like the 1.25” nosepiece in the OAG was spurious, it measures up better without it. Now for some faffing in the daylight, to see if it’s even close...so far, I know the imagining can focus ??

[Yawning Angel]

Well, it works in the daylight...on trees. Maybe I should image squirrels, as I see them more often than stars at the moment!