10/25 Shingletown shoot-out report

by Bruce Sayre

I arrived at the air strip alone late PM Thursday and started set up around 5:30 at the far north end of the strip. It was windy but clear. I did a little observing, but retired at midnight. I'd say winds were 5-15 mph, with gusts to 25. Good transparency; mediocre seeing.

On Friday, Dan Gray and Mel Bartels arrived from Oregon and settled in on the opposite side of the strip. Dan brought his new 28" string scope and Mel brought his 20" tri-lateral Dob. Dan had added digital setting circles since OSP and was using them with David Lane's "Earth Centered Universe" planetarium software. As Dan manually slewed the telescope, the software displayed its location, the target and nearby objects. Various zoom levels afforded simple object location, as long as Dan's startup initializations are accurate and he could read the display.

Friday night was worse. Winds gusted over 30mph. Vibration plagued us all, seeing was poor, and transparency was a little worse. We spent over an hour comparing views of NGC 891 between all three instruments. Views of the galaxy's dust lane were very much the same between the 22" binocular and the 28" with regard to detail and surrounding stars, although one really faint star was easier to see on the 28". Dan's mirror is still a work in process, and only temporarily silvered, so it was optically unfinished and the silver surface was slightly tarnished. Comparisons were no doubt affected. Mel's 20" probably has one of the finest optical surfaces made by an amateur, and performed nearly as well with its sharp images.

Because of the poor seeing, we threw in the towel around 1:00 AM. None of us drew any conclusions that night. At least the temperatures were balmy. This was the same night Jim Ster reported nearly being blown off the mountain at BC.

Saturday night we were joined by Bill and Shneor. Mel and I spent a few hours working on Shneor's encoders -- the first time we had tried them out. After getting them plugged in right and getting the motors going in the same direction as the encoders (stupid me), we had it up and running. Mel demonstrated the power of his SCOPE software by automatically panning Shneor's 22" around the full circumference of the Veil Nebula. Under control of what's called a scroll file, the scope stopped at a number of points in the Veil, then let panning continue when Shneor pressed a handpaddle button.

The evening was more promising: the wind was down considerably, transparency was good and the seeing was average. We compared views of M110 and M57. We could easily pick out the spiral structure of M110 in both telescopes; the views were nearly identical.

We agreed the granularity of M57 was a little more impressive with the 22" binoculars. Pink sections of M57 were easily seen with the 22" binoculars. Magnification was 168X and no filters were used. Although not carefully compared, the binocular view of the Perseus double cluster was also considered very good.

Using Shneor's Denkmeier Binoviewer on the 28" provided the comfort of using both eyes, but differences in magnification due to eyepiece restrictions made image interpretation harder.

I think the consensus was this: the 22" binocular and the 28" were very comparable, although our brains really preferred to use both eyes and could do a better job picking up color and improving contrast. We agreed there really was a neurological effect. The comfort of using both eyes with the 22" seemed to reduce "noise" in the background, so images seemed smoother.

Dan, Mel and I think a 22" Newtonian binocular and a 30" monocular with a binoviewer would provide nearly identical views and comfort, although lower power options would be sacrificed with the 30". I think it would be great to try this again with Jim's 30". Maybe next year!