Posts Made By: Brian Risley

Ron,
As one of the first to do the marathon back in 1987, I still had to rely on a list and finder cards to locate all the objects. Norm McLeod and I had been trying for years, coming close (>100) several times before 1987. Even with that experience, we had to rely on charts and aids, especially in the dense galaxy regions and the areas where dusk or dawn was going to make things difficult. I only used co-ordinates on 1 or 2 objects with my C-8 and we didn't use any co-ordinates with Norm's 12" f4. Even today, I recall where some of the objects are, but I don't have the ability to recall where all 100+ are. If I was showing the objects regularly to others, I might be able to, but not regularly trying to find some objects makes it impossible for me to find more than 1/2 of the list without going to some aid.
I have a very good recall, but not photographic. I suspect someone with a photographic memory could do it with no aid, and I could probably get to 70-80% if I regularly found them for a few weeks and re-aquainted myself with the Leo/Virgo area groups under darks skies.
The key being dark skies. Most of the objects will show in a good finder if you are in 7.0+ skies, but in today's light polluted environment, I would be hard pushed to find them all (not talking marathon here) from my house like I did in the late 70's/early 80's.
I can see the need for goto, I just roboscoped a SP mount with an Autostar, but I came from the old school of star hopping and sometimes using manual setting circles.

Brian Risley

Keith,
The C-90's come in several flavors. There was the standard orange tube spotter with the photo tripod mount. This style also came in an astro version with a single arm slimmed down version of the C8/C5 fork. There were also rubberized versions and black body versions.
I have one of the earlier orange tubes. In the early 80's, I kept the unit in my van attached to an OM-1 with Focus Screen 8 or 9. Pulled it out whenever I saw something unusual. Loved it. Front barrel focus just like a regular camera lens. With 800/1600 asa, I was often shooting at 1/500 or 1/1000 sec. Did everything from still life macro to radio controlled planes in flight. (They filled the frame, looked like real planes shot with a regular camera up close.)
By default, the C-90 is designed to take .965 eyepieces and a special T-adapter, but you can get a LAR (Large Accessory Ring) and use standard SCT accessories. That is what I had, a LAR and standard SCT T Adapter. Fit my hand well and was well balanced. If I had a good DSLR today, I would use it with my C-90. jsut can't afford one.
I even mount mine piggyback on my C-8's to give lower power views compared to the C-8 when doing public sessions. (Front barrel focus when mounted piggyback is a pain though.)

Brian Risley
Celestron Moderator

Mine on my black tube pried off. Use a thin wide flat blade screwdriver. It was a little tricky.
Brian Risley
Celestron Forum Moderator

Double Cluster

M15

Andromeda

Gil,
You are in luck.
Robert Piekiel wrote an e-book about these older Celestrons (blue&whites)
See ad #516967
http://www.astromart.com/classifieds/details.asp?classified_id=516967

He has the history and technical information on these models.
Congratulations on getting a classic!
Brian

It seems there is a flood of dup AM and CN ads again.
I don't feel like warning each one of these about 15.2.h as I have done in the past.
I am hoping they notice this and take proper action.
Brian

Good Shot.
I have been able to see it quite a bit. Here is a compilation of 47 2.8sec shots with my DSI Pro using a Cometron 62 piggybacked on my SPC-8. (Don't think I had darks being subtracted.)
This was shot 11/11 at 6:02 ut. I can see the same stars that are in yours to give a motion perspective.
Brian

Some of the digitals do use TEC (Thermo Electric Cooling). Not sure if they go as low as CO2. Issue with the cold camera was reloading it with dry ice and dealing with film chips. It has a large glass plug to keep condensation from forming on the film/glass. Many of the digitals use an optical window/sealed chamber or some other means to prevent the condensation issue. With TEC, no reloading/bumping the scope/camera, consistent temperature.
Used a Cold Camera once, real pain!
Brian Risley
AM Celestron Moderator.