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looking for some advice

Started by kevlvm, 06/23/2008 03:49AM
Posted 06/23/2008 03:49AM Opening Post
Been long enough to qualify as a beginner, my equipment
1 - 8" Discovery reflector - purchased as eq mount - the not so great one that came with a lot of scopes. Focuser is suspect-probable upgrade
1 - Stellarvue 80/9D OTA w/rings - use the same mount
Telrad finder
Red Dot finder
Some EP

I'd love to get back into things but not sure I'm happy with what I have. My gut says sell everything and start over, but not sure thats necessary and was hoping to get some ideas as to what is useable or to go in a different direction. Thanks for thoughts
Posted 06/23/2008 04:21AM #1
Kevin VerMerris said:

Been long enough to qualify as a beginner, my equipment
1 - 8" Discovery reflector - purchased as eq mount - the not so great one that came with a lot of scopes. Focuser is suspect-probable upgrade
1 - Stellarvue 80/9D OTA w/rings - use the same mount
Telrad finder
Red Dot finder
Some EP

I'd love to get back into things but not sure I'm happy with what I have. My gut says sell everything and start over, but not sure thats necessary and was hoping to get some ideas as to what is useable or to go in a different direction. Thanks for thoughts

Kevin: It does seem that most of us go through a process of discovering what it is we like to do and discovering the equipment is suited for our particular needs. So buying and selling equipment can be part of the game. Astromart is a big help in this regard as it allows us buy and sell equipment without taking a huge loss...

Not knowing what you are interested in doing, he's a few random thoughts:

- An 8 inch Reflector and an 80mm refractor make a nice combination, it's a nice balance, one is well suited for wider field of view work, one is best for widefield and "grab and go."

- As I remember it, the 8 inch GEM mounted Discovery is F/4. They probably chose F/4 because of the mount was undersized and not up supporting a longer OTA. The advantage of an F/4 scope is it's compact size but in an 8 inch, for visual use, the disadvantages seem to out weigh the advantages. F/4 means collimation is very critical, that coma is a significant issue and that almost all affordable eyepieces will exhibit serious off-axis aberrations that show up as very rough looking stars. With Naglers for the Astigmatism and a Paracorr for the Coma, an F/4 can perform nicely in the widefield but it a big price to pay.

So, I would recommend swapping your EQ mounted Discovery for something with a slower focal ratio, either F/5 if you still want to go with a EQ mounted scope, or F/6 is a Dob mount seems more attractive/affordable. Either an 8 inch F/6 DOB or a 10 inch F/5 DOB would be reasonable choices and keep the budget under control.

As far as the 80/9D goes, that is a reasonable 80mm, at this moment I would think there would be little reason to swap it out. Being an Achromat, it will show noticeable false color on bright targets at high magnifications but since you have/will have a larger scope for the high magnifications, this is not a serious limitation.

That's my two cents, hope it helps...

Jon
Posted 06/23/2008 06:40PM #2
Kevin VerMerris said:

Been long enough to qualify as a beginner, my equipment
1 - 8" Discovery reflector - purchased as eq mount - the not so great one that came with a lot of scopes. Focuser is suspect-probable upgrade
1 - Stellarvue 80/9D OTA w/rings - use the same mount
Telrad finder
Red Dot finder
Some EP

Hi Kevin,

I wouldn't swap out the Stellarvue unless you really want an APO. It's a good achromat. It's also hard to get much over $200 for the OTA. I bought one for my daughter here, and we really like it. (My personal 80 is an APM super apo, so it's not as if I don't have an idea what "the best" is.)

I'd love to get back into things but not sure I'm happy with what I have. My gut says sell everything and start over, but not sure thats necessary and was hoping to get some ideas as to what is useable or to go in a different direction. Thanks for thoughts
Posted 06/28/2008 09:49PM #3
Could somebody compare the different types of telescope - what would one see if you had a 8" SCT, 8" Dob and any other styles - straight up optics comparison. Just curious if one is "better".

Kevin
Posted 07/13/2008 01:51AM #4
I have a 12" dob that I keep on a garden cart. When I need a quick astrofix after a hard day's work, I wheel it out when I get home and by the time dinner is over I'm ready to go. It is my most used scope
For more serious observing I use an 11" Celestron NexStar GPS.
Am putting together a 100ED on a GEM mount for when I travel.
George T'man