After re-collimating the primary mirror (which, I found, was loose in the mounting cell) I got the scope out again to take advantage of the exceptionally clear skies, and to try out the new Baader 8-24mm zoom eyepiece and various combinations of camera mountings.
After doing the polar-alignment and 3-star alignment routines, I told the handset to slew the scope around to Mars for a quick look before it went out of sight behind the house. With the eyepiece set to 8mm, I could just about make out some faint surface detail, but I couldn't capture it on camera as there was too much ambient light from the surrounding houses, causing excessive diffraction-spiking.
Next was Saturn. I got great views through the zoom, the Cassini Division in the rings was well-defined and all five of the main moons (Enceladus, Dione, Titan, Tethys and Rhea) were visible. I set up the D50 and took a series of afocal shots through the 20mm eyepiece at various camera settings, trying to find a good compromise between exposure time and aperture. Here's a montage of the nine best pre-processing images:
D50 with 70-300 lens @ 70mm, f/4.0, 1s, ISO 200, through 20mm ep in C8-N, Feb 09, 2008
Focusing is still a little out despite using a home-made Hartmann Mask (made from a bit of grey closed-cell sit-mat), this is mainly due to the low-tech sloppy focuser supplied with the scope. I need to get it shimmed-up to take out some of the axial play.
I had a look at a NGC 3628 (edge-on spiral galaxy in Leo), M45 (The Pleiades), M40 (double-star in Ursa Major) and M44 (The Beehive Cluster, also called the "Praesepe", in Cancer) before packing away before everything got dewed-up.
The new tracking motors worked well, acceptably quiet and fairly accurate, although I've still to go through the Periodic Error Correction routine and I also need to refine the backlash settings. I've a minor cone-error on the scope mounting-plate which I'll correct as soon as I get the time.
THE SMALL(ish) PRINT... (updated 23/07/2016)
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