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Douglas Rollain

Lion Nebula SH2-132 - RC71

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Posts Made By: Linton Rohr

June 9, 2005 05:13 AM Forum: Eyepieces

The 1.5-3mm Exit Pupil 'Sweet Spot'

Posted By Linton Rohr
In the Backyard Astronomers Guide, Dickenson and Dyer refer to a 2mm exit pupil as being optimum in terms of the eye's ability to resolve detail. So the optimum EP for an f/10 SCT would be 20mm, 10mm for a f/5 reflector , etc.
"This rule isn't hard and fast, but it serves to point out which eyepiece you should invest in most heavily. If you can afford just one top-end eyepiece, make it the one with a focal length about twice your scopes focal ratio."
I bought a 20mm Nagler for my 8" f/10 SCT last year during the sale, with this in mind. Fortunately, it seems to work fairly well in the f/4.3 Starmaster, as well. wink I guess my sweet spot EP for it would be my 8.8mm UWA. Though I'd really like to try a 7mm T6. Anyone?
Linton 8)

June 12, 2005 03:57 AM Forum: Star Parties

GCSP Reports

Posted By Linton Rohr
Thanks for the report Jim.
Maybe I'll make it next year.
Glad you had a good time.
Welcome back.
Linton

June 12, 2005 05:06 AM Forum: Deep Sky Observing

NGC 5139 (Omega Centauri)

Posted By Linton Rohr
Wow! 8O I got a good look at 5139 last night in my 20x80 Skymasters. Had I tried it as my first object, instead of viewing Saturn and Jupiter first, I could have resolved it in the Starmaster. But it had just slipped behind a hillside by the time I dialed it in on the SkyCommander. Drat! By moving to the other end of the parking lot, I could see it in the binos, but I didn't want to disassemble and move the scope. :S
I was quite impressed, nonetheless, with the sheer size of Omega Centauri compared to M13. shocked Yowza! I hope I can get it resolved in an eyepiece next time out.
Linton

June 17, 2005 04:46 AM Forum: Beginning Astronomy?

UHTC Coating

Posted By Linton Rohr
Menahem,
I don't know all that much about coatings per se, but I believe when you are trying to observe light that has been traveling through space for millions of years, EVERYTHING between the front end of your scope and your eye is important.
Linton

June 24, 2005 05:27 AM Forum: After Dark

Where to View in Malibu

Posted By Linton Rohr
Hello Ben,
You're much better off heading to the north, than the east. Check out the light pollution map on this local clear sky clock.
http://cleardarksky.com/lp/EglRdgObCAlp.html
I could direct you to a good spot near Pt. Mugu, if you contact me privately. wink
Linton

June 25, 2005 05:03 PM Forum: Equipment Talk

Re: most knowledgeable

Posted By Linton Rohr
Well said Tom. We are fortunate to have all of those named. They are performing a labor of love. It is not a popularity contest. To attempt to pick a #1 top dog is insulting to all the rest.
Linton

June 29, 2005 04:49 AM Forum: After Dark

You know it is a dark sky site when.........

Posted By Linton Rohr
I was going out to a new site in April and was running late, so it was already getting pretty dark as we approached the turnoff. I glanced out the window, while driving, and instantly saw the double cluster. Wow. I looked again and saw M37 within moments. I was afraid to keep looking - I wanted to get there in one piece. Good spot. I've returned....
Linton

...It ought to be like that everywhere.

June 30, 2005 05:49 AM Forum: Star Parties

Date Place White Mountain Star Party

Posted By Linton Rohr
Cool. Thanks for organizing this, Brett.
I have marked my calendar and hope to attend.
Linton

July 4, 2005 08:21 PM Forum: Deep Sky Observing

Tempel Crash Party

Posted By Linton Rohr
I'm surprised you couldn't see more Floyd.
That's based on the Hubble before and after photos I saw.
http://deepimpact.jpl.nasa.gov/gallery/Hubble_Witnesses_Crash.html
There was one good report from Pheonix too, in the After Dark forum.
At least you went out. That's more than I can say.
Linton

July 10, 2005 07:58 PM Forum: Pictures of Me and My Telescope and........

Starmaster at Vasquez Rocks

Posted By Linton Rohr
Here's a better view of the site. An interesting spot...

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