Meade Microfocuser Position

[thunderchildobs]

What is the best order of the following

scope + f6.3 focal reducer+ Microfocuser + t-adapter + ST-7
or
scope + Microfocuser + f6.3 focal reducer + t adapter + ST-7

My previous configuration was scope + f6.3 focal reducer + t adapter + ST-7. I am curious how the microfocuser will affect reaching focus.

Brendan

[Merlin66]

I assume we're talking about the #1209 Zero Shift focuser.
I found to get close the the design distance between the reducer and the CCD that the reducer was mounted after the focuser ie back cell- focuser- spacer(?)- camera....
I use the Orion two piece Prime focus adaptor to fit the SCT reducer to the 2" focuser.
The attached spreadsheet shows the EFL at various distances....
Ken

[mldee]

I use a QHY8. For what it's worth, I tried both ways and found I got better results with the FR on the C8 OTA, followed by the Meade then the T adaptor stuff. I have both a Meade and an Antares 6.3 and although it's still early days, I think the Antares seems a little more tolerant. I believe FL for the Antares is 78mm and for the meade is >100mm, forget actual number.

One small advantage of having the meade in between is you can use the main OTA for coarse focusing, and use the meade as a +/-8mm or so spacing adjuster, as you really only need to move it a mm or so for fine focus. I think this is why I liked it better that way.

[Merlin66]

The Meade x0.63 reducer is 240mm fl ( there's some urban legends still persisting about the "bad" batch of short fl made when Meade initially transferred manufacturing to China) and the x0.33 is 88mm fl.
As far as I know, the x0.63 is designed for a distance of 110mm between the reducer and the CCD chip.... not so clear for the x0.33...
Ken