FS 60C + dslr issues

[graham.hobart]

Played with the DSLR and FS 60C on the weekend and noted again the coma. I have the correct reducer/flattener according to the sytem chart but could not reach a focus point with it in the mix-(flattener)
Does anyone use an FS 60 with a DSLR + flattener?
Can they advise me how they set it up?
I can reach focus with Canon DSLR, T mount, Tak T tube extension and then screw mount to scope. I have tried directly replacing the T ext tube with the flattener and also adding threaded extenders.
I got my flattener from Tak Australia dealer so I assume it's the right piece.
Cheers
Graham:thanx:

[naskies]

Have you checked the system chart for the flattener (p. 15 of the manual linked below)? The recommended image train is the Camera Angle Adjuster, SD ring (optional), flattener, wide T-mount, DSLR.

http://www.takahashiamerica.com/manuals/FS-60C%20Manual.pdf

It sounds like your back focus is too short (i.e. flattener/camera is too close to the OTA) when you have the flattener attached - possibly because you're missing the CAA? - but too long when you add the extension tube in with the flattener.

From memory, I think there wasn't much spare travel in the focuser on my FS-60CB with the recommended flattener configuration.

The easiest way to check for sure would be to centre your scope onto a bright star, leave the OTA bare (i.e. don't attach anything to the focuser), have the flattener attached to the wide T-mount/DSLR, look through the DSLR viewfinder and slowly move yourself closer/further away from the OTA until the star snaps into focus. That will show you what the required distance is - and you'll be able to figure out whether you're too close/far from the focus point.

[graham.hobart]

Cheers folks- I got the reducer sorted now- took the SD ring out of the equation and it seems to be OK
Thanks again
Graz:thumbsup: