Astromart

Chas,

I curious about whether you perhaps saw Ganymede, rather than IO. Ganymede is the largest and brightest moon and seeing barely perceptible details on this moon seems more likely. IO never shows more than its yellowish tint to me. With my SM-16 goto, I can on great nights, resolve all the four major moons as disks at about 500X, but though I can make out slight differences in color, have not been able to see any real detail in my skies near Memphis. I have, however, heard of others resolving details on Ganymede with ZOC mirrors as small as 12.5", so I do not doubt your observation in your excellent Florida skies. I'm just curious whether it was actually Ganymede.

Randy

March 21, 2004 09:18 PM Forum: Equipment Talk

Celestron Pacific

Posted By Randy Roy

David,

Celestron Pacific used to advertise in S&T in the late sixties when I was a teenager. I believe they introduced the C8 in 1970. Here is a print of the instruction manual for the C8 apparently from 1975, but possibly earlier.

http://www.company7.com/library/celestron/c5-8manual1971.pdf

Does this look like your scope?

Randy

March 22, 2004 03:15 AM Forum: Equipment Talk

Cheshire disagrees with Laser

Posted By Randy Roy

It sounds like your optical axis is not perfectly coincident with the mechanical axis of your optical elements. One likely source for this problem is a focuser that is not square with the diagonal. I had this problem with my dob until I leveled the focuser and now the cheshire and laser agree. Until you get the two axes aligned, you will chase collimation between the cheshire (optical axis) and the laser (mechanical axis).

BTW--Others may disagree with this, but I found the cheshire will give me good optical collimation, while the laser will give good mechanical collimation. What this means is that my images were fine when I collimated with the cheshire but soft when I collimated with the laser. Only when I got the mechanical axis aligned with the optical axis did the laser give an accurate indication of the optical collimation.

Randy

March 28, 2004 01:36 AM Forum: Equipment Talk

CEMAX EPS

Posted By Randy Roy

Douglas,

I have the set and believe they are quite good plossls and pretty contrasty because of the care with darkening the inside metal surfaces. I would rate them up there with TV plossls for that purpose.

For purposes of viewing the Sun, IMO they are as good as you get.

Randy

March 28, 2004 01:18 PM Forum: Equipment Talk

42" dob-nice dust cover

Posted By Randy Roy

I thought of a couple of punch lines about the garbage can secondary cover, but then I went to the URL listed and I now have nothing but respect for this guy. Even the thought that went into getting it into the trailer was brilliant and executed superbly. What an incredible setup!

Randy--too wimpy to get my 16" dob out last night for the triple transit and used my 3" refractor instead.

March 28, 2004 01:32 PM Forum: Takahashi

Herb and Paula visit TNR

Posted By Randy Roy

Herb,

Art FedEx'd my new P2Z mount (purchased through Anacortes ) the day you were there. By gosh, I've never seen anything so perfectly packed in my life--no detail too small and nothing missed. This was a better pack job than NASA did on the Rover.

Your guys say that's because you were there. . .chuckle:>)

Randy--(just kidding Art!)

Image of the day

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Posts Made By: Randy Roy

Astomart-aholic - 10 Step Program ?

Can one believe this?

Somebody tell Al Nagler he mispronounces his name.

Anyone tried to burn ants with an ST80? (nm)

Detail on IO with 11" Starmaster

Celestron Pacific

Cheshire disagrees with Laser

CEMAX EPS

42" dob-nice dust cover

Herb and Paula visit TNR

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