Posts Made By: Leif Edmondson

I'm re-entering amature astronomy with a homeade 10" f/6 dob from the 80s. It could use a good collimation job and probably a recoated mirror but despite this it still turns in fair to good performance today.
I have just begun building a 16" f/5 truss dob in hopes of getting better DSO visual results. I recently read about resolving the span between the two galaxies of M51. The author seemed to indicate 20" and up would really be needed. My current scope can't do that in my back yard (roughly mag 3.5, maybe 4, skies). To-date i've been fairly disapointed by Messier galactic objects. It does get quite a bit better when I drive out of town to Mag 5 or 5.5 skies, but M31 is still just a big smudge.

The traditional advice is 'join a club' (done) and look through a bunch of stuff (still in the process of this - there's a club 18", a big party in a couple of weeks, and publicly available 25" Obsession about 1 hour drive from here that I haven't looked through yet). So I think I'm on the right track. I'd like a little encouragement that building a new bigger bucket will be worth it.

I'm thinking of building a new little 8"er and I'm really not inclined to grind my own. Most of the big shops like Torus, Nova, Galaxy, Swayze, etc. don't seemed to be to interested in the little stuff like 8" but I still want to buy high quality.
What do you DIY builders think about the quality of Discovery, University Optics, or Orion mirrors?
I'm attracted to the discovery 8" f7, anyone know of a modern producer that's selling an 8" f8 mirror?

The Messier objects in Sagitarius are AWESOME! I only had about an hour to really look for things and I didn't even get all the M objects in that constellation. M22 was just amazing. It seems bigger than M13 but didn't appear to have the surfance brightness.
I was trying for M24 but never found it, instead I think it was M23 or M25 but cant recall from work, It was an open cluster with gas clouds near by. WOW what a sight.
The constellation was low on the horizon at 1 am and realy didn't get good until 2 and by then I was beat myself.
I must remember the NODOZ and bug spray next time.

How does Akira Fuji, of Sky and Telescope, make those photos of the star constellations for the "binocular viewing" column each month?
His pictures have all those dim little stars between the big bright ones, the huge wide angle? What kind of gear do you have to have to do that?
I'm more impressed by his wide angle, rich fields than I am by the solitary deep sky objects.

My parents owned a Nikon 35mm manual focus camera when I was growing up.
I bought an adapter to hook it up to my 10" F6 dob and the shots of the moon turned out great when I was 16. I'm now 35 and still own the adapter and telescope but not the camera body. Can any of you recomend a Nikon Camera body to use for this? Do I need to provide more details for help? Let me know. I was looking on e-bay and used F3 camera bodies seem reasonably priced. I've never liked autofocus cameras and see no need for one in astrophotography (if I'm wrong please educate me).

Since many of the active writers are Refractor users I know I can get good feedback here.

The definitions I have of an Achromoatic lens include statements about how the "lens does not exhibit chromatic aberration" and "A lens system that refracts light without spectral color separation". Yet when I read the threads on this list or reviews of refractors on other sites I see statements like "very little extra color" or 'with x EP and this telescope there was discoloration at the edges', and most of you recommend APO's over achros if the writer can afford it etc. Do achros really show that much color? If so why is the dictionary definition telling me that its a system designed to eliminate color?

I've been contemplating an AT1010 as a finder for a big dob, as quick look scope, and potentially as an astrophoto lens on a GEM. But some of the "go APO" cheerleading has me a little nervous about it. It's just that APO's cost BUCKS, that I'd rather throw into the primary mirror for my Dob.

Appreciate your insite

For those of you that build telescopes out of aluminium parts, what kinds of tools/blades/bits do you need to cut aluminium sheet or "L" stock.

I'm building my own triangular spider out of wood and aluminum. I plan to use screws to hold the metal vanes to the wooden block but I'd also like to apply glue to it as well. Can anyone recommend a wood to aluminum glue they have used and had good results with?

As I hunt down the Messier catalog objects this winter I read the NGC "Dreyer description" and I wonder about Mr. Dreyer's descriptions. He calls M79 (a cluster in Lepus) "pretty Large". The Andromeda Galaxy is 'pretty large' M79 is TINY. Does anyone know if Mr. Dreyer used a set of guide lines, for instance M79 is 8.7' according to my software, so are all objects from 5 to 10' in size 'prety large', while things from 11 to 20' 'large'? Or are his comments purely subjective? I know many of you out there have studied this kind of thing far more in depth than I have so I'd appreciate any free education you're willing to share.

I star tested my dob last night. Never done it before. The one website I've been reading says I should see concentric rings of light. Maybe I wasn't at high enough power, but all I got was a large disk with the shadow of the secondary in the middle. Is this what you're supposed to see or should it be these conentric rings the author spoke of? I was pointing at Venus, it doesn't get much brighter than that. Any pointers or free advice, or links to websites would be appreciated.