AutoFocus and Riccardi and Honders

I’m buying a Riccardi and Honders Astroraph with a 50% obstructed secondary Newtonian.

Will AutoFocus work (using Gemini focuser/rotator); I’m hearing maybe not with these types of scopes.

Still hoping for sub framing and auto focus to be offered (tiles?)

Thanks for the help/guidance

Rick
cardiofuse observatory

About a year or so ago we had some issues with centrally obstructed scopes. Those issues have been addressed and should work just great.

Thanks,
Jared

I use an 8" RC with about 45% obstruction and have no problem with auto focus.

BobT

Awesome, that is great news!

Thank you for the confidence.

Should the smart focus be used or disabled. I’m also getting a OS RH-200 and wasn’t sure if the recommendation to disable applies. In fact, I’m not sure what smart focus does…

I have the AP RH 305 and the Gemini rotor focuser. It works great with SGP.

Thank you. Is that using smart focusing or not ?

Yes Smart Focus is ON (box unchecked).

I have an RH200 with 2" Feathertouch and HSM and they work very well if your scope is well collimated and tilt is negligible. If that’s not the case then results won’t necessarily be as good as you expect.

One thing to note is that your focus motor needs to have enough resolution because the CFZ is quite narrow.

You won’t be disappointed with the scope, it’s excellent.

Hope that helps
Robert

+1 on the collimation. My 10-inch RCT is difficult to focus period if the collimation is not spot on. This is due to the fact that the star is not being rendered as a uniform blob - but as a weird shape as it approaches focus.

I’m getting the RH250 and it has a long back focus. I am pairing it with the Gemini focuser/rotator which is a massive unit. I think it was built for NASA. It has over 200,000 steps in 12mm so sub micron motion Apparently the secondary never needs touching so it’s down to three screws, a laser and the tilt plate. Wondering if I need CCDInspector now. Anyone using the Howie G on this?

You can do the same analysis in Pixinsight as CCDinspector.

I use PI often. Would you share your technique of squaring the primary using PixInsight? I was told by others that the main concern is fine tuning the tilt/tip plate after the primary is collimated.

Sure try Script> Image analysis> FWHMeccentricty.
Select and image and hit measure and then support. It gives you a map of the elongation errors in the image.
Graph is not a cool as inspector but it works for me.
Max