Greetings to all,

I enjoyed the postings I have read and found them to be entertaining and informative, but none addressed the problem I am having.

I have a vintage 1995 Orion DSE 8 in. Dob. Since I've owned it, when viewing the planets there is a ghost image of the planet. There is no problem with deep space objects or the moon. As I come to focus the ghost image almost overlaps the main image, it is minimal slightly out of focus but then, of course, the planet is a blurr.

The scope original came with a helical focuser and single stalk vein. I have replaced this configuration with a JMI focuser and four vein secondary. The improvement made no difference in image quility, only in ease of use.

I have collimated and re-collimated using both a film canister and a laser to no avail. I have noticed that the primary is not blackened in any way on the underside. Could this produce a reflection? Is heat management so important to reflectors that it would create this sort of problem?

Thanks and Seasons Greetings.
Dave

• I think I know - comet61 - December 14, 2001 - 01:56 UTC