Ruin etc al,
What is the distance from an SCT thread to the M42 focal length? I plan to use mine with that little 50mm APO you had in your hands with the 400 series camera at NEAIC. The SV50ED has an SCT thread when not used with the 1.25" diagonal.
You can also email me off list if you have the specs for this.
Thank you,
John Sillasen