Last updated: 13 July 2004
Subject: First optical check of new ETX-105 Sent: Sunday, July 4, 2004 16:13:59 From: James Eagle (firstname.lastname@example.org) I purchased the ETX-105 to have a 4in. portable scope to use on camping trips to the Sierra and Rocky mountains. I had thought that sitting the ETX on a picnic table viewing the dark, mountain night sky would be just about heaven. And it would have been, too, had there not been clouds and thundershowers almost every afternoon, with the clouds generally lingering into the evening. I had used the scope for 2 nights before leaving on this trip, but was not confident of the optical quality. The seeing was not steady enough to really tell. If the optics were not sufficiently good, I'd return the telescope. (I also have a 4in. Vixen/Orion fluorite apochromatic refractor, which has essentially perfect optics, I believe; but with the equitorial mount and counter-weights, is not as portable as I wanted for traveling.) In any case, after 10 days of clouds, I finally had a clear night last Friday (2 July 04). We were camping at Donner CA State Park near Donner Pass at just under 7000 ft. The afternoon cumulus cleared shortly after sunset at 8:30 pm, and by 9 I had Jupiter in the viewfinder. (I did an Easy "faux-alignment" by immediately hitting "Enter" when the slewing to the alignment stars was complete. The sky was too bright to see either Vega and Atair. Then I did a Go-to Jupiter ... did not come very close ... but close enough to find it, center, and "synchronize" on Jupiter by holding down Enter. Even though Jupiter was only about 30 deg. elevation, it was a beautiful sight. Ganymede, Io and Europa were visible, with Ganymede looking bigger and whiter than Io. There was some detail visible in the two major cloud belts, suggestions of other cloud belts, and a very noticeable darkening at both poles. With Jupiter at opposition and the seeing good, I've seen the Jovian moons as tiny disks in my 4in apo, but this view was almost as good. I then slewed to Vega and the famous double-double Epsilon Lyrae, which was almost overhead. The view was essentially perfect! Both doubles split at 100x, but the view at 150x was textbook-perfect. Four tiny Airy disks, each with 1 or 2 shimmering diffraction rings. I'm keeping this scope! Unfortunately, clouds reappeared at about 1030, but I had accomplished by main mission ... testing the ETX-105 optically. And it passed with flying colors. JimMike here: Thanks for the report! By the way, SYNCing on the planets or the Moon is generally not a good idea. It will be OK for some nearby objects but will likely get worse the further you get from the planet/Moon. Of course, the same is true for SYNCing on stars but less error will creep in.
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