Congratulation Bob,
Your focal length is 714mm, is't it ?
With camera do you use for guiding ?

I begin to get descent shot at 5minutes with a 300mm F/5.6 canon lens.
Guiding with a 60/240 scope and a ZWO 120MM.

Best regards
Eric

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Eric
Nargis (45) France.
57 years old, Computer science engineer.
Some skills in sofware development (Windows / Unix)
Canon EOS 10D, 40D, 600D 1300D, EOS-R. + several lenses.
ToupTek IMX 294 cooled camera.
ZWO ASI120MM
BRESSER Messier AR-102xs/460, Bresser Messier AR-152S/760
Orion 80ED.
MAK INTES 713.
Meade LX200 GPS 10"
Old Losmandy G11.
SvBony 60mm x 240mm guide scope.