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Posts Made By: Lorne Johnson

April 16, 2003 08:20 PM Forum: Equipment Talk

Question about min. aperture needed for DSO

Posted By Lorne Johnson
First, the 8" dob is a great compromise. I think that many people get an inexpensive 8" dob as a first scope, and then feel that they need some else (which is normal enough). But, what you may actually want is a better built 8" dob, possibly with setting circles. My 8" dob weighs 38 lbs, and I can carry it around in one piece. There's a 10" Discovery dob in today's listing for about what I paid, but the tube weighs 57 lbs and the base another 24.

I also have a 5inch MakNewt because it is the largest scope I could afford to put on a GEM and carry as one piece. It has wonderful images, but not the structure in say M 51, 81 or 82 that I can get in the 8". It shows the veil and N.A. nicely though, and the Rosette nebula. In a 3 degree field of view I can actually see M31, and the Orion, Swan, and Lagoon all show structure.

April 24, 2003 01:19 AM Forum: Equipment Talk

D&G refractors

Posted By Lorne Johnson
I have good friend who owns a D&G 5 inch f/12. It's a wonderful scope, with wondeful views. I have an MN 56, and on a particularly good night of viewing, for New England we put them head to head on Saturn. Seeing started to limit magnification at about 220x for both scopes. True color was definitely better in the D&G, largely because the image was brighter (as one would expect). There was less false color with the Mak Newtoian, as one would expect (as it's an APO). I have never found the color to be ojectionable on the D&G.

The MN 56 is more practicle for me. It's 30 inches long, mounts nicely on a Super Polaris, and is better for widefield because it is f/6. Much as I like the D&G it's huge, and his new mount is "huger." Neither of us would trade scopes. But, if you are set up for a permanent or semi-permanent installation, D&G are the long focus way to go, and you would not be dissappointed.

May 1, 2003 01:22 AM Forum: Eyepieces

Pro Optics Ultra-Wide Eyepieces

Posted By Lorne Johnson
I haven't used enough eyepieces over time to develop a really strong understanding of this beyond a number of specific comparisons. A lot of eyepieces work relatively well in longer focal ratio scopes. Fast scopes are hard to design eyepieces for, especially widefield eyepieces. Televue eyepieces are all designed for excellent correction in scopes down to f/4. This makes them especially useful in fast refractors and dobs. (It also makes them expensive.) Their advantages are considerably less in longer focal ratio scopes.

May 15, 2003 01:12 AM Forum: Equipment Talk

1rpd AstroBuffet 30mm ST80 Eyepiece

Posted By Lorne Johnson
For what it's worth Anacortes confirms that it will ship it's preorders on May 15.

May 17, 2003 10:43 PM Forum: TeleVue

Televue Pronto vs. Stellarvue SV78S

Posted By Lorne Johnson
Either one is a good scope for your purposes. The Televue should have less color, and about 30% less lightgathering power. But, given your uses, I would go with the Ranger, which is substantially lighter than the Pronto and cheaper. I don't think that you need the extra apeture for guiding.

May 20, 2003 01:21 PM Forum: Equipment Talk

UO High Definition orthoscopics

Posted By Lorne Johnson
There is a short thread in the eyepiece section. I think that his assessment was marginally better (probably simply premium coatings, but not worth even thinking about replacing a classic set.

May 23, 2003 01:17 PM Forum: Deep Sky Observing

TV-102 first DSO sketch: M51

Posted By Lorne Johnson
I think that's pretty good! Especially since it looks like you sketched what you could see. I'm hoping to start some sketching when I get some time maybe next winter and spring. Thanks for showing it to us.

May 23, 2003 03:50 PM Forum: Equipment Talk

Discover Mirrors

Posted By Lorne Johnson
I would agree with Darian that Mark Harry is the custom maker who really specializes in 6 and 8 inch mirrors. Bob Royce (rfroyce.com) also makes them, but an 8" costs almost as much as a 10". They both have fine reputations.

Still, the Discovery mirror is a quality mirror, and at f/7 you can go with either a 1.52" (19%)secondary, or a 1.3" (16%) secondary.

May 24, 2003 12:42 PM Forum: Deep Sky Observing

Observing Log - 05/22/03

Posted By Lorne Johnson
Get yourself to a dark site. You will be pleasantly surprised.

May 24, 2003 06:53 PM Forum: Eyepieces

Winged eyecup

Posted By Lorne Johnson
It fits the older plossls such as th 10.5 13 and 17, and also the older Nagler 4.8 and 7 mm. Possibly others. I don't know how to buy a new one, but would try Televue for a start.

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