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orion 100mm ed

Started by cysmarc, 03/31/2006 12:54AM
Posted 03/31/2006 12:54AM Opening Post
OK here goes: Using my ep's with and w/o barlows I can achieve 35,50,60,70,90,100,120,180x. I live in light poisoned Brooklyn NY so I only have limited viewing. viewing was through an orion 100mm ed. Saturn was beautiful I saw the southern eq. belt and Cassini division very easily as well as several moons. Sirius and other stars were very nice and showed pinpoint patterns with 1 diffraction ring that I could see. I woke up at 3:30 a.m. to catch Jupiter and I believe I saw the grs at 120X
it was to the left of center on the lower belt at around 3:45 a.m. 45min to an hr later the grs was further left. Am I crazy or did I really see it ? It wasn't red but a big bulge was clearly noticible in the cloud belt. It was absolutely amazing. The mount is smooth and very easy to use and the focuser shows no shift and no shakes. That was last night

However, tonight I'm a little perplexed. The bright stars seemed to not be pinpoint but like little tiny plus signs. Coma :S ? My eyes sad ? Some other abberation? Please tell me NO.
Someone please let me know.

Posted 03/31/2006 06:55AM #1
>>The bright stars seemed to not be pinpoint but like little tiny plus signs>>

+ sign means the image has classic astigmatism. Could be caused by differential temperature, cell pinching the optics, tube currents due to insufficient cooldown etc.

Posted 03/31/2006 07:54AM #2
You might also check the telescope w/o the diagonal, to see if the diagonal is the problem.

Darian R.
Posted 03/31/2006 08:52PM | Edited 03/31/2006 08:53PM #3
If the astigmatism is only seen at low powers, could be your eye's astigmatism. I have that problem. TeleVue's Dioptrix works!

"--Granted, that's a worse case scenario. The destruction might in fact be ... limited to our own galaxy."