Excelsis - Display Vote

DGM Optics OA-4.0

OK here we go. This is only the third scope I have ever looked through and I did alot of reading before I got this scope. It seem to be the best value I could find. This was important for me since I am a single father of three going back to school at 36. I ordered the DGM 4.0 over the internet and mailed a check to Dan McShane. Later I got a call on my cell phone from Dan himself asking if I wanted to buy a different configuration and generally just talking about what I would be using the scope for and my interest. This was very nice and helped me get over the reservations I had about buying a scope before I could look through it and compare it with other scopes. After about 2 months he emailed me telling me that the scope was finished and about 2 weeks after that I mailed him the rest of the money. The first thing to arrive was the OTA minus the primary. The secondary was mounted in the very black interior of the PVC tube and it was very loose on the verge of falling out of it's mount. This caused me considerable trouble when doing my initial alignment the next week when the mount and primary arrived. The reason was that proper alignment of the secondary is very dependant upon the distance of the secondary from the primary and normally it is set permanently before it arrives. I tightened it down without thinking much about it until later when doing star test and getting some false color from veiwing bright planets. This was not the fault of the scope however but UPS and Dan was very helpful over the phone and email. I have since worked out most of the problems and am a better astronomer because of it. The only other problem I had was that the tube cradle would slowly slip as I was observing near zenith. Dan was very concerned about this report and was willing to replace the mount but this was not a big deal to me as I wrapped a peice of thin poster board around the tube where the cradle held it and all was well.
Now to the good stuff. The new friction band on the altitude wheels allows me to use any combination of eyepeices and barlow and change them at very high magnification with out worry of the tube moving. Balance is easy to change and the movement is silky smooth in all directions. I am basically a novice and I could track Saturn at 510x, yes 510x, with this scope by nudging the planet slightly out of the feild of view and enjoying the jumbo sized image pass across my feild of view. The damping time is just under 3 seconds and actually comes in handy when jiggling the view for close doubles ect. On the first night of good seeing I was doing things as a novice with this scope that I didn't think I could. I split Rigel very easily mostly because there are no difraction spikes. The reflection nebuli around some of the stars in the Pleadies were strikingly apparent, and the three components of Castor were just easy. Saturn was all there with 4 or 5 moons. The Moon was better than any picture I have ever seen at 70x very 3d and absolutely no false color...creamy white with charcoal black shadows. I also cranked to power up to 510x with a shorty barlow and sure it was fuzzy and hard to focus but not all of the time! every once in a while the casinni division would pop into view and so would cloud bands and ring shadows any fault lies with the atmosphere more than the optics.
I use a fold out canvas camping chair to observe on and I can carry it and the scope with mount at the same time over short distances. Once you align this scope it is just a matter of learning how to starhop to use it. If you are new and you want to get into amature astronomy without learning to starhop well......after playing with this scope I think that is alot like wanting to swim without wanting to get wet. With a low power 30x eyepeice I can just point this scope at a random spot in a dark sky and just go wow. Less than a minute to set up and 30min to come to ambient temperature I leave it in the garage so 0min for me. I think maybe my optics are a bit spherical because I still have a bit of color on Jupiter but this might be my eyepeices because I don't have the most expensive lot and the color seems to be linked to where the image is in the feild of view. However the color is very slight and only apparent on Jupiter. When I read post about people having trouble finding Rigels companion in 8" scopes of lesser quality I wonder if maybe I am just a bit too picky about optics having not seen too many examples, for Rigels companion was very obvious to me wiht this scope at 80x. The workmanship is top notch, very nice woodwork. I like the helical focuser especially for star testing, good idea to put denser lube on it after some use though.
Accessories needed: You will want a cover for the end of the tube to keep dust off the primary, get a nice spotting scope, and high quality 35mm or so wide feild occular, and nice 12.5mm or so and get a UO 7-4mm ortho for the planets and for star tests. If you want a barlow make it a shorty because the secondary is right next to the focuser. My favorite targets for this scope are
Low power open star clusters...... WOW
Globluar clusters...................very nice
The Moon better than a 3d video game.
M42 ........................................cool.
The planets ........................very nice.
Binaries performs to theoritical limits.
Things I still need to work on
Galixies and dim fuzzies......maybe a bit much for 4" they are there but not over whelming..next scope big Dob! Glad I got this one first though.
Clear Skies from Oklahoma.

Overall Rating: 10
Optics:10 Mount:9 Ease of Use:10 Value:10
Weight: 6 (Veritable Vote)
Date: 01/05/2003 09:41:05 pm PST
By: shane_sweeney
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=175329

Articles like this make life so much sipmelr.

>OK here we go.......agian.
This is a follow up. I have gotten to know my scope now and have learned its strenghts and weaknesses. Now that I have gotten good at aligning this thing the veiws are incredible. In the last year I have learned how to "see" and how to tweak my optics. I have resigned to the fact that it is nearly impossible to keep your optics clean and that it really doesn't matter very much as long as your secondary mirror has been wiped down with alcohol and cotton.

This scope can do anything a apo refractor can do and the color is perfect. It scatters the light a very very slight bit more than a refractor so you lose .1 magnitude off of theoritical. Resolution on doubles is to the limits. 

Strenghts
Planetary views. Cloud turbulence on Saturn 5 moons visable.  
Double and multiple systems. Rigel very easy. "E" component of Theta Ori. Zeta Ori wide and clear at x252.
Globular Clusters.
High power airy discs are text book   "o" dim stellar components pixey dust. 

Weaknesses
Delicate.
High maintainence. but hey I like to tweak...

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