February 18, 2009

First light with the C11-SGT

My user level:

Long time fan, 8-month observer with Nexstar 8i. I was pretty happy with my Nexstar 8i until my wife kindly bought me a Meade DSI, which made me need to upgrade to a serious (but not fanatic mount). Of course, the Aperture Fever forced me to go all the way to the 11". These are my impressions, as they occurred.

Expectations for 1st Light: I expected set up on the patio (5 miles north of downtown San Diego, very bright) to fool around with the mount, maybe Utilities-->Polar Align. Look at Saturn, Orion Neb, M81, M82.

First Impressions, Mount:

I used to think observing was fairly non-aerobic, but many parts, some heavy, plus contortions in lining up polaris thru axis, I think I can use as yoga waiver.

The OTA seemed a bit heavy for the mount, a few seconds to damp a nudge. Still, much more stable the the N8i.

Visually aligning Polaris: I'm in San Diego. The Alt Adjustment screw lever really liked to interfer with the gear housing. Had I been doing the design I would have made sure CONUS would be in the clear.

The dovetail connection seems less than failsafe; there were a few times I thought it was secure when there was some "slack" in it. I wonder how many people have thought they had it clamped, only not to (I've let go of infants with less trepidation).

I did put the OTA on backwards initially. Now I know.

Balancing was pretty straightforward (are you with me, Mr. Dovetail?).

I bought the Celestron Quick Release finder Bracket as I couldn't see unscrewing the delivered bracket every time I store the OTA. I read in a post that the screws could potentially touch the mirror so I shimmed it up with some cardboard. The cardboard compressed and the finder shifted from the alignment I did the day before. I found this out after 15 minutes or so.

Initial Impressions:

Power Up & Align GPS unit was "searching" longer than the Time edit timeout, so it assumed it was 8:00p instead of 7:00p as it headed towards Sirius, which was off by about 10 degrees. Center & Align. It then wanted to go to Canopus (at this point I hadn't checked the Site, having figured the GPS did the location, if not the time properly). I undid until Regulus. Centered, Align and finished with Capella. Success.

Impressions, Observing: Saturn was near the zenith but the slew was close (I don't remember if it was within the FOV of my 11mm Nag). The seeing and transparency was fairly good for 5 miles north of downtown San Diego. Saturn was comparable to through the N8i (in fact inferior to a couple of nights). Atmospheric bands suggested, Cassini Division obvious.

M42 slew centered in FOV. The nebula seemed more detailed and brighter than through the N8i.

M82, GoTo got it within the FOV. This definitely has more "presence" than in the 8i. Very cool.

Some imaging Impressions: I'm still winging it with the Meade DSI (am using a 6.3 focal reducter), but felt like giving it a shot. The N8i, on the patio, the one time I tried it, had about an 8 second max exposure before stars became seagulls. 30 second exposures with the C11-SGT gave only-slightly elongated stars. 60 second exposures gave trails, but this was without doing a Utilities-->Polar Align (also, I learned today how to keep the sequential images separate to align before combining, so I should be able to do much better tonight).

Overall Impressions:

I am happy with the purchase. I think the OTA is a lifetime keeper; the mount will be completely adequate for visual and a good learning and skill building photo platform that I won't "outgrow" for a couple of years. I like the imaging stuff cuz it gives me something to do from the backyard on those moonlit nights and on the computer on the cloudy ones. $3000 for a mount just isn't viable for me now and may never be. In the meantime, I think I've got a good combo.

Thanks to everybody who answered my earlier questioning posts and to our group moderator the FAQ's are excellent.

Post Mortem:

Child born in October. Given how long it takes to set up an equatorial, I never used it much. I bought a 6" SCT tube, whose ease of use inspired me to immediately sell it and this C11 and buy a (used) Nexstar 11 GPS, which has been a very good match.