[avandonk]

Mike the focal length is 1018mm with MPCC as measured against a TAL200K image (FL 1790mm with FR/FF). This is close to 1016mm that the scope nominally is quoted and well within errors. The OTA was modded with an aluminium plate fitted under the focuser for extra rigidity. The focuser had also been upgraded to a 10:1 Crayford. The mirror cell had also been strengthened and better/more bolts added. The SN is designed by Meade for astrophotography so focus position is far enough out to obtain focus with a DSLR or astro cam.

I bought it from an IIS member from the for sale threads on IIS. I did not really need it but it was to good to pass up at $1k with MPCC and the intelligent mods. When Ken James gets the Snake Valley Observatory built will park it down there where the dark skies would make the 10" at F4 really usefull for dim objects. It really needs to be permanently mounted. The field is remarkably good for full frame and any vignetting still makes nearly the whole frame quite usable. There is little or no vignetting on a C size sensor and in fact the superimposed Tal image is just a bit smaller than the field of a C sized sensor. The vignetting is mainly caused by the MPCC which has a rear aperture of 40mm. The diagonal on a full frame is 43mm.

Below is a flat taken with the 5DH and two jpg's straight out of the camera superimposed with RegiStar to show difference in fields between the Tal and the 10" SN.

The HDR process will show from noise to the brightest object. The night was hot 26C.

Bert