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A perfect morning with Jupiter Part 1

Started by tomhole, 12/27/2003 05:16AM
Posted 12/27/2003 05:16AM Opening Post
Good morning everyone,

I am visiting my parents in southeast Ohio and decided to bring my Starmaster along. They have never looked through a telescope, so I figured I might show them a few celestial treats. Am I ever gld I did. The skies are mag6 with no lights except ones that I could turn off and the seeing was 9+. Oh my goodness, did they ever get a treat. I also had a chance to compare the Denk stds and TV binovues on a tough target (Jupiter) under great conditions (except for the 10 deg F temp).

Equipment: 11" f/5.4 Zambuto Starmaster (16% CO). TV binovues w/ 2x corrector, Denks stds w/ 2" OCS in 1.4x mode and 2.5x mode. 24 Pans, 12.5 UO orthos, 11mm TV plossls, 10mm Antares Ultimas, 9mm Nagler type 6's, 7mm UO orthos. Transparency: very good. Seeing: Perfect 75% of the time.

At 9:00 (2100), Saturn was very good, but we were looking over the house to see it. Not the best I've ever seen, but very good. Lots of Oh my Gods! with this one. No issues with the binoviewers and merging with the entire family ranging in age from 7 to 67.

Went to bed and got up at 0500 for Jupiter. It was not over any man made objects. It was VERY cold out and the Starmaster's exterior had frost everywhere. The ep cases were outside as well and the ep's were COOOOLLLLD. I put the TV's in with the 9 Naglers (339x) and nearly fell over. This is the level of detail I could see (including the color):

http://www.tomhole.com/images/jupitergood2.jpg

Unfortunately, no GRS transit, but there was a moon transit just finishing up. I went up to the 7mm orthos for 436x and could not believe that the image held up. I liked the view better at 339x as it had a bit better contrast, but 436x was very good. So, here I am freezing my butt off looking at Jupiter at the limits of the cpability of an 11" Zambuto dob with a 16% CO using binoviewers on a tracking platform. The only thing missing were the Juggy Girls on trampolines and a bigger telescope wink

cont'd
Posted 12/27/2003 05:16AM #1
I tried all the ep pairs I have and the best view of Jupiter was with the 9mm Nagler T6's in the TV's. After tonight, I am convinced the type 6 Nagler is the equal of the UO orthos with a lot of added AFOV. I also looked at the 11mm TV plossl and 10mm Antares Ultima. I felt the 11mm TV plossls were not up to ortho performance. The image was not as sharp or contrasty. They will need to be replaced by 11 Nagler T6's. The 10mm Antares Ultimas had a great image, easily matching the orthos and Naglers, but the ergonomic design is not good. The flat top with the recessed upper element makes them almost unusable. They are not keepers. If not for the perfect (and I mean PERFECT) seeing, I would be reticent to draw conclusions on ep performance so quickly, but it was obvious under such ideal conditions.

Initially, I wasn't going to waste great seeing like this on testing. I spent 45 minutes just staring in amazement and then decided I couldn't resist. I put the Denk's in with the 2" OCS in 1.4x mode with the 7mm orthos(305x). I left the 9mm Nagler t6's in the TVs for 339x. Although the Denk view was very good, the TV definitely had the edge in the level of detail and overall contrast I could see. I put the 10mm Ultimas in the TV binovues to exactly match the mags at 305x. Same result. I could definitely see more detail and better contrast in the TV's. This matches what I had seen in Aug on Mars but was a bit more evident under these excellent conditions. I really want to try this again with the 12.5 UO orthos in the TV's (244x) and the 9 Nagler type 6's in the Denks (238x). Hopefully tomorrow morning will be as good wink

I decided to put the Denk OCS in 2.5x mode. The whole mag before the prisms, less glass, etc... I used the 12.5mm orthos in the Denks at 2.5x (305x) and the TV binovues with 2x corrector and 10mm Ultimas (305x). This one I had to swap back and forth a lot. The Denk's put up a silightly better image. It was subtle, but most definitely better contrast and the same sharpness. I could see the same detail in the TV's, but it was slightly more contrasty in the Denks (especially in the SPR). Hmmm. Can't let those Denk's beat up on my beloved TV plantet killers. The 10mm Ultimas must be the cause. I decided to put the 9 Naglers in and whup up on those upstart Denks. Hmmm, I still like the Denk view a little better. The Denk's in this configuration with the 12.5 UO orthos (my favorite orthos, BTW) had slightly better contrast than the TV binovues with the 10mm Ultimas or 9mm Nagler type 6's. This difference was more subtle than the difference I saw between the TV 2x and Denk 1.4x comparison. But, it was definitely there.

cont'd