PDA

View Full Version : Rejiggering A Junk Telescope



Charlie in Dayton
2003-Jan-13, 07:37 AM
Have this 3" Tasco junker I bought off ebay. The tube looked as if it had been used as a softball bat, but surprisingly it cleaned up quite nicely with a rubber hammer and a body dolly. It's now mounted on an Orion EQ-2 equatorial mount. Problem is, this thing has .965" optics.
I'd like to go with 1.25" optics, and am thinking about converting this scope over to them. But everyone I talk to brings up something else that would need changing. So far, we're talking about a new focuser, a new secondary mirror, repositioning said secondary, and figuring out how to mount the new focuser. Is this more trouble than it's worth?
I'd like to get to the point I can do some astrophotography this summer with Mars' closest approach in 60k years. I'm seriously considering just a .965-to-1.25 adapter and new eyepieces. Would conventional 1.25 astrophotography equipment work on this thing with the adapter? (I'm referring to T-rings, etc -- and I've been checking ebay for 35mm camera deals. Older Canon AE-1's, Olympus OM-1's, and some early Nikon outfits are going absolutely dirt cheap!!)

Glom
2003-Jan-13, 11:14 AM
According to the BAG, write it off and get a new one. Barrel adapters apparently don;t work with reflectors because it throws them out of wack. Replacing the focuser would probably involve greater cost that simply buying a new one.

Kaptain K
2003-Jan-13, 04:41 PM
I second the motion. For the money that it would cost to bring your scope up to "half-way decent", you can buy a "good" scope. Some projects just aren't worth the effort.

Glom
2003-Jan-13, 04:57 PM
Certainly since it's 3 inch, you won't be able to do much. You'll only be able to get 160x magnification before the resolution cuts out on you. It's not worth the time or money. You'll probably get just as much from a good set of binoculars.

aurorae
2003-Jan-13, 07:18 PM
On 2003-01-13 02:37, Charlie in Dayton wrote:
Problem is, this thing has .965" optics.
I'd like to go with 1.25" optics, and am thinking about converting this scope over to them.


You can buy an adapter. I know Orion (US) used to sell them, which will allow you to use 1.25 eyepieces in a .965 focuser.

Depends on your budget, but I'd suggest considering this scope a trainer. Maybe it could be used as a finder on a larger scope someday. /phpBB/images/smiles/icon_wink.gif

You could try to take pictures of something really bright, like the moon, by mounting a conventional camera on the eyepiece. But anything more sophisticated is going to require a really good motorized mount.

<font size=-1>[ This Message was edited by: aurorae on 2003-01-13 14:19 ]</font>

Glom
2003-Jan-13, 07:21 PM
Apparently, though, that only works for refractors. According to The Backyard Astronomer's Guide, using those adapters on reflectors places the eyepiece too far from the tube to successfully focus.

David Hall
2003-Jan-14, 09:13 AM
Use the scope for sunspot observing. Buy a cheap Mylar sun filter and take it out during the day. As mentioned above, the Moon and brighter planets might be good targets too.

If you look around, like on ebay, you might also be able to find one or two decent eyepieces that would fit it and not set you back much.

aurorae
2003-Jan-14, 03:44 PM
Note, as Glom points out below, I misunderstood his previous message, so this message is a "Never Mind" (imagine a Gilda Radner voice here).



On 2003-01-13 14:21, Glom wrote:
Apparently, though, that only works for refractors. According to The Backyard Astronomer's Guide, using those adapters on reflectors places the eyepiece too far from the tube to successfully focus.


Depends. If it is prime focus, then yes on some scopes you wouldn't be able to get the camera to focus. However, adding a barlow lens, or using an eyepiece to get additional magnification, may allow you to use a conventional camera on a reflector.

Some people even hand hold digital cameras at the eyepiece! (only works for very bright objects) I have seen a company that sells some kind of a bracket to hold a digital camera in place.

Actually, it's easier for me to get my 35mm camera to focus on my newtonian than on my refractor.

YMMV.


<font size=-1>[ This Message was edited by: aurorae on 2003-01-14 19:19 ]</font>

Glom
2003-Jan-14, 04:11 PM
/phpBB/images/smiles/icon_confused.gif

I wasn't talking about camera adapters, I was talking about eyepiece barrel adapters. On refractors, you can get adapters that slot into a 0.965 inch focuser and allow you to use 1.25 inch eyepieces. But according to the BAG, they can't be used on reflectors. The only way to change the compatible barrel size is to completely replace the focuser.

I use my 35mm SLR very successfully on my Newtonian.

<font size=-1>[ This Message was edited by: Glom on 2003-01-14 11:14 ]</font>

Charlie in Dayton
2003-Jan-16, 01:21 AM
Thanks for the input, folks. I've just about made up my mind here. Now the only question is, which new scope do I buy? The 3" 1.25" optics Orion reflector with extra eyepieces for $65? The 80mm Celestron refractor with dual axis drives, battery pack, and solar filter for $200? The Meade D2114ATS 'go to' scope with numerous bells and whistles for $300? Or hit a nickel slot machine on vacation and buy 'em all?

Decisions, decisions, decisions...

patrioticamerican
2003-Jan-17, 03:40 AM
Charlie,

I wouldn't bother with a "go to" scope unless it was at least a 4" refractor or 6" reflector, because almost all the objects you could "go to" would be too faint to see well in a smaller scope. If you want to do photography with film, you'll need an equatorial mount with a clock drive (you could track manually, but that would be a lot of trouble). If you do planetary photography with a digital camera or webcam, you could get by without the drive. However, a drive is very desirable for long period, high power observing. A good 80mm refractor would do nicely for planetary work. Here's a good website with lots of scope reviews:

http://www.cloudynights.com

And here's a company that makes excellent, relatively inexpensive refractors:

http://www.stellarvue.com

Good luck in your search!