friend selling celestron gp-c102, worthwhile for me?

[mtbdudex]

My friend is selling his celestron gp-c102, he also states k.20mm eyepiece on 45% diagonal on gp base. He says over 10 years old.

My Q:'s
-what's reasonable price for this?
-I want to make sure my T1i can"fit" with attachments, ballpark $$ for those
-it does NOT have drive motors/GPS, ballpark to upgrade?

In other words, if I want to start astrophotography, should I buy this used and spend $$ for more, or buy a "better/newer" scope w/drive motors/gps instead?

I'm totally new to astrophotography, and appreciate your advice.

[DonR]

That telescope on the non-motorized GP mount sold originally for about $1400, but that was before the revolution. An equivalent achromatic refractor on non-motorized EQ mount today would be around $500, brand new. Bear in mind that the C102 was made for Celestron by Vixen, a highly respected Japanese manufacturer whose telescopes command premium prices, but still it's a 10 year old achromatic telescope and likely no better in optical quality than a modern mass-produced Chinese refractor. Chromatic aberration will be substantial due to the achromatic optics.

At f/9.8, the 1000mm focal length would be challenging, and even if you could find drive motors for the mount, I doubt that you would have any success without autoguiding at that focal length- and the GP (Great Polaris) mount is not capable of being autoguided to the best of my knowledge.

Another strike against it is the 1.25" focuser, too narrow for prime focus DSLR photography. There would be substantial vignetting caused by the narrow focuser drawtube.

In it's day that was a quite respectable telescope made by a well respected manufacturer, but even then it wouldn't have been a good choice for astrophotography. Assuming it's in good condition and the price is reasonable (under $400 I would say), you could get some enjoyment out of it for visual astronomy but I think it would be a mistake to buy it for astrophotography.

By the way, although drive motors are mandatory for most DSLR astrophotography, a GPS is a waste of money on a German Equatorial mount IMHO. The most benefit you can get from the GPS is not having to enter your latitude and longitude and the date/time if the mount is computerized.

[Adrena1in]

I think DonR probably said it all.

That GP-C102 sounds fairly similar to my first "slow" telescope, which was a Phenix 5" 1200mm Achromatic Refractor. For observing the moon and planets it was great, and it was pretty good for photographing them too. (Ball park costs for fitting a DLSR to a telescope focuser is negligible...around $30-$40.) My mount was driven, and had GOTO software, but the scope and the bare-bones mount would have cost me around £500 new if I included a diagonal and a couple of eyepieces...so perhaps £250 secondhand. As DonR says, $400 perhaps.

From my own experience, and my desire to get into Astrophotography, had I not bought a driven mount I would have immediately wanted to upgrade. I also would have immediately wanted a faster scope, in order to shoot deep sky objects and such like.

If you really intend to get started and have nothing yet, and are on a bit of a budget, then I would personally start by looking at something more like an ED80 Apochromatic refractor on a driven mount at least. Secondhand you could get a complete package along those lines for around $600 I expect.

[mtbdudex]

Thx for quick feedback guys, I'll pass on the gp-c102 and further research my foray into Astrophotography before buying whatever set-up I eventually get.