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Walking on the Moon

First Light: Crayford Focuser On ST120 Frac


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This dual-speed focuser has utterly transformed the ST120.  It's always easy to use (on the AZ4), and the widefield views (about 4.5 deg) with the 42mm Revelation are spectacular.  But now, without the slack in the R&P focuser, it is more of a pleasure , and without the jerky action I experienced before, the fine control gives really sharp focus.

Cassiopeia/Perseus Region:

M103 open cluster - mag up to x100 showed several stars, with the main six resembling a miniature Plough.  (Noticed this also with Cr89.)

Cr15 - open cluster - tight line with just a few stars.

M45 (Taurus) - always a treat, particularly with a panoramic widefield view.

Mirphak starfield - no particular designation, just a lovely view!

C14 Double Cluster - just aimed the RDF between Miram and Epsilon Cas, and easily spotted the target in the wide view - an all-time favourite.  Upped the mag to x60 for detail.

M52 open cluster - again, "hopping" was done by aiming, this time between Caph and Iota Cep, and only one "key" star was noticed.  Stellarium confirmed the location, and raising the mag to x90 revealed a small, dense cluster of faint stars, the view enhanced by AV.

I enjoyed the freedom to sweep rapidly across the celestial sphere, with widefield views all the way, then the satisfaction of homing in on a target.  It might then take more mag to reveal detail and enhance contrast compared with using the GoTo SCT, but that just makes it a completely different experience, with different challenges!



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Hi Doug. The Crayford on the ST120 makes it a much better scope to achieve focus with. It is so smooth to use, and solid too.  Nice report. Didn't get out last night even though it was clear as I was too tired, but hoping to later on tonight. 

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