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M20 Trifid Nebula in LRGBHa

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Posts Made By: Lorne Johnson

June 12, 2003 03:53 PM Forum: Eyepieces

Seibert lenses - disappointed

Posted By Lorne Johnson
Mine have been very sharp, and with good contrast, I have a 21 and a 12.5, and certainly no tan haze. I would return it as it looks like there is something wrong.

June 23, 2003 03:54 PM Forum: Telescope Making

first project, secondary questions...

Posted By Lorne Johnson
2.6 or 2.14 are the obvious choices. 2.6 would be "better for deep sky with a more fully illuminated field," and 2.14 "may give slightly better contrast for planetary viewing." There is a theory that central obstruction should be held to about 20% for best contrast, and 2.6 at 21% it pretty damn close. The 2.14 still looks good on the SEC program, and a 17% central obstruction. 2.6 is probably the more conservative all around use choice. But, I don't think that you could go too far wrong with either, and people do change there secondaries on occasion so it's not cast in stone.

June 28, 2003 04:08 PM Forum: Equipment Talk

4" TV-102 kicked 8" Discovery Dobs

Posted By Lorne Johnson
I all fairness the Televue 102 costs more than 4 times what a Discovery dob does (unless you want a mount for the Televue). So it should walk all over the dob, if money has meaning. Of course, we both know what's going to happen in good seeing and dark skies. And, naturally observers should optimize their scope to the conditions where it will be used.

July 14, 2003 03:35 PM Forum: Deep Sky Observing

Unencumbered by Knowledge II

Posted By Lorne Johnson
You aren't going to see M101 with a full moon, at least not very easily. M57 is pretty bright (partly because it is small) by faint fuzzy standards. You could get M81 and 82, but not to enjoy. Dark sky are worth a lot for deep sky.

I grew up in Ipswich by the way (and at 51 I must be more or less contemporary), and while Boxford was pretty rural then, I wounder what your light pollution is like like now. Where I live in Putney VT, it's still pretty dark.

Best of luck!

July 18, 2003 08:44 PM Forum: Eyepieces

30mm KK Widescan III vs BW Optic 30mm

Posted By Lorne Johnson
I believe that the Widescan III is the same design as the Widescan II was, but has blacked edges better coatings, and quality control. (This is a paraphrase of Markus Ludus).

I have the B & W version, and it is a very good eyepiece, though not as strong in faster scopes. There hasbeen at least one informal comparsion, which I believe gave an edge to the Widescan (but I can't remember if it was on this forum or the Cloudy Nights). I prefer the Siebert 36 mm Observatory, although it is not the same focal length.

July 22, 2003 01:24 AM Forum: Telescope Making

6" mirror manufacturers

Posted By Lorne Johnson
Just to largely repeat what has been said, Mark Harry and Bob Royce are both excellent mirror makers. 6 to 8" I would go with Mark Harry (its his specialty) 10 to 16" I would go with Bob Royce for the same reason. Nothing wrong with Mike Spooner (I have one and will never sell it) Carl what's his name, or a number of others.

July 24, 2003 03:48 PM Forum: Eyepieces

13mm Nagler T6

Posted By Lorne Johnson
I would agree with you, it's an incredible eyepiece.

July 26, 2003 07:06 PM Forum: Equipment Talk

How I avoided aperature fever

Posted By Lorne Johnson
I'm with you Mike. I love my 8" dob. I can pick the whole thing up and carry it outside and across the street (dirt road really) about 200 steps, no problem, it seems to need very minor adjustments in collimation about once or twice a year. I use it all the time. Some people do the same sort of thing with a 10", and it may work fine, but I'm happy right where I am.

That 14 inch T scope is pertty tempting, but I suspect it would be a once or twice a month instrument, so I think that my daughter's wish for a pony comes first.

August 12, 2003 01:12 AM Forum: Refractors

Clarks v. Moderns

Posted By Lorne Johnson
Many years ago I used a 5" f/15 Alvan Clark quite a lot. The field wouldn't go much above 1/2 a degree, but the views were very, very good. My old observing partner says that it was very close indeed toa 5" Takahashi. He has used both extensively.

August 12, 2003 01:14 AM Forum: Maksutovs

Where to get scope rings?

Posted By Lorne Johnson
Ken's rings is a very good place to look. So is Parallax instruments. Both sponsor Astromart.

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