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#1 5RNS

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Posted 20 August 2013 - 12:12 PM

I've been scouring the forums looking for info to help me make a decision on whether or not to trade in my current scope. I have a C8 with the special coatings I believe. From another thread here it looks to date near 1980. Serial number 803100 .
It has the standard tripod and a wedge. I don't have any motor control equipment but the scope is fitted with motors. Obviously this puts me in manual mode for viewing.
So my delima is now that I'm interested in AP and having a scope that tracks so my kids can enjoy the sky without loosing an object every few seconds, is it time to let this one go?
My budget won't afford me any more aperture, but is a newer scope of the same size a better performer? Is this scope worth investing more money into with a new mount?
Looking forward to your opinions.

#2 Ham Radio

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Posted 20 August 2013 - 01:41 PM

If the motors are working on your scope, and you get a close alignment then the scope will do fine for keeping things in view for you.

#3 bremms

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Posted 20 August 2013 - 02:22 PM

Newer C8 won't really be much better and will cost a lot more.
Previous poster is right on the money. Plug the motors in, if they are spinning, you should be good to go. You will need to know how to polar align the scope. It will track fine for visual use that way.

#4 Joe Cepleur

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Posted 20 August 2013 - 03:06 PM

When I got my first vintage C8, I thought the motors were broken, but they were fine. Here's how to test them:

Plug in the scope and look up from the floor at the underside of the base. The two motors are easily visible (little round gizmos). Each has a tiny, clear plastic window, through which you should be able to see the motors spinning. Unplug and re-plug while looking in the windows; you'll see the rotors stop and start. You may need a flashlight if the windows are in shadow.

If that doesn't help, plug in the scope, lock the Right Ascension clamp (or both clamps, if you are uncertain which clamp that is), and walk away for a few hours or an afternoon. If upon your return the scope is pointing in a new direction, the motors work. If the scope has not turned, ask here.

You would not benefit from a new optical tube. I have not yet dabbled in astrophotography, but I've promised myself that when I do, my first trials will be with my vintage C8. Astrophotographers say things have changed a lot for the better, but the vintage fork mount was state-of-the-art at the time, so it would suit me for old-school trials.

I worry about all the excitement over astrophotography, not because I'm at all against this amazing new art, but because it distorts people's sense of the equipment they need. If you sold your vintage C8 for the latest astrophotography rig, you would lose an ideal scope for visual use, yet hardly make a dent in the cash needed for your new scope. (Even excellent vintage C8s are embarrassingly inexpensive relative to new scopes.) Better to keep and use the vintage C8 and add a modern astrophotography scope and mount than to lose what you already have in exchange for essentially nothing.

That said, I'm a visual guy. I'm sure the astrophotographers will have far more to say, but if you want a scope that tracks the skies for your children, you already have exactly what you need.

#5 Falcon-

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Posted 20 August 2013 - 04:24 PM

I think I would get a new mount and keep the C8 OTA. It is quite easy to de-fork the C8 and add a dovetail (and equally easy to re-fork the mount to restore it to original). This is what I have done with my Orange C8, de-forked with dovetail for easier use on my modern mount, but with fork intact waiting to receive the C8 once again

What mount to get with AP in mind will depend on your budget. A Celestron Advanced VX or iOptron ZEQ25 should be sufficient for visual with the C8 and good for AP with camera lenses and wider field scopes (people have had success with a C8 on that class of mount for AP as well, but it is more work and may have mixed results).

If your budget can afford it an Orion Atlas EQ-G, Skywatcher EQ6, Celestron CGEM, or iOptron iEQ45 would allow for AP though the C8 easily.

With deep-sky AP it *always* pays to get the best mount you can afford. A poor telescope on a good mount will give better results then an excellent telescope on a low-end mount. :)

#6 SteveNH

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Posted 20 August 2013 - 05:19 PM

I'm not a hard core astrophotographer, but it seems to me you'd be trading apples for oranges if you got rid of your C8. As others have said above, the drive motors will do a great job straight off the power outlet even without frequency control. My C8 is close to your vintage (807390), and has proved to be an excellent instrument both for the kids in outreach sessions, as well as a fine portable visual scope. For me, precisely like Joe says above, I would never recover its full value if I were to sell it off.

Your C8 on a fork mount is a very capable instrument for lunar and planetary astrophotography as well, where you'd be using a webcam type camera like the old Philips SPC-900NC or a ZWO ASI120-MC and shooting video that would be stacked. Critical tracking requirements are relaxed because of the video, although a frequency controller does help. But for many deep space objects, more precision in tracking would be required, and an optical system with wider field coverage and brighter than what an 8" f/10 offers is usually preferred. This would get you more of the Andromeda Galaxy and Veil Nebula, for example, in the field of view. That typically means getting a high quality fast refractor on a substantial GEM mount, like the Celestron CGEM that I got, used for around $1000 (mount only). As Falcon mentions above, this would also be the class of mount that would easily hold your C8 for narrow field deep space astrophotography (especially with the f/6.3 reducer), although many have used it on its original fork mount for excellent shots of planetaries like the Ring and Dumbbell Nebulae, as well as globulars like M13. It all depends on what you want to shoot, and the time and money you want to invest in this separate hobby, or branch, of amateur astronomy. If you plan to do planetary photography, upgrading would usually mean more aperture, as the shots below will illustrate:

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#7 5RNS

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Posted 20 August 2013 - 09:36 PM

Thanks so much for the great replies. it's comforting to know my old Orange C8 still holds it's own compared to the newer ones.
I should have stated that I do not have any of the control hardware. Not even a power cord. I'm sure they can be had, but since I truly despise the rigid tripod I have no intent on getting them.
I had been looking at the CG5-GT mount but after some research here it appears to be less than adequate for my needs.You guys have recommended some mounts so it looks like I have some more research to do.
I will say that go-to is a must. AP is probably a long time down the road for me at this point.The majority of my scope time is viewing with family.
Keeping my current scope is my preference. It may also enable me to pick up a 100mm or so refactor for 4x4 trips that require more portability. One thing at a time though!
Can anyone tell me how much my OTA weighs?

#8 Joe Cepleur

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Posted 20 August 2013 - 10:49 PM

I truly despise the rigid tripod



For your own sake, be sure you understand it before you despise it. Celestron's Locked Field Tripod is a *great* feat of engineering. In exchange for not being adjustable in height (which is no loss, since you can always rotate the eyepiece down if necessary), it is stiffer and better at dampening vibrations than far, far heavier tripods. The legs are made of straight lengths of spring steel, and are forced into their curvy positions with the fittings at their tops and bottoms. Pre-tensioning the steel creates the stiffness and dampening properties. It is among the finest and most misunderstood tripods available. It is far lighter to schlep into the field than anything else you'll ever have.

Power cords are easily obtained on eBay.

If astrophotography is "a long time down the road" just now, you already have everything you need. Learn to use it. When you truly understand it, and why it is so sought after even thirty-eight years later, then you'll be ready to consider buying new gear.

GoTo is fine if you want it, but if you've ever watched people fuss with their GoTos without getting them to work, you'll appreaciate that you could just as easily learn the skies and find plenty to see with the scope you already have. That would also make you a better astronomer. Join your local club. People there will teach you how. Your vintage C8 will teach you, if you let it!

#9 5RNS

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Posted 21 August 2013 - 12:14 AM

Joe, I appreciate your candid reply. It does have me rethinking my position and considering all my options. Admittedly I have ZERO experience with go-to set ups.

I can see that you truly have an appreciation for the C8 tripod! Can't say that I will ever share it with you. By reading your sig it looks like our scopes are of nearly the same vintage.

#10 orion61

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Posted 21 August 2013 - 02:58 PM

Hi 5RNS: FIRST of all welcome to the Forums!!
Gary Hand at Hands on Optics, sells them for about $20.00 shipped. If he is out I have an extra one.
You have one of the best tubes on the Market right now.
As many here will attest to, those old Orange tubes are a Passion of mine, and I have refurbished quite a few, one from Joe here. Nobody has asked the question of what kind of AP do you want to do?
If it is just Planetary, with a power cord you are set as far as the scope goes. If you want to take Deep Space Images then that is a different story, that scope is not that well suited.
It can be done but you would have to buy a Dual axis drive corrector & a Dec motor.. It's just not worth it.
For having fun with the kids, and neighbors, and for Lunar and Planetary Imaging all you need is a ccd Camera about $50-75.00 used. The software can be found for free.
You already have one of the best compound (Mirror Lens) scopes ever made.
Please feel free to PM me for more detail, I can even set up a time to call you, I will do anything I can to help you out..
Heck for a couple hundred bucks and some searching you can even find an after Market Computer for your scope! The JMI Max and MiniMax are great and accurate, I have used one on my Orange C8 since the 80's!
All the best of luck, and be assured "There are no dumb questions here" We are all friends and have been where you are at one point..
Again,
Welcome to the Forums!
Larry

#11 5RNS

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Posted 21 August 2013 - 07:16 PM

Larry, Thanks for the warm welcome and your offer to help.
I have learned quite a bit in from this thread.I'm really happy to know I have this great scope already. I just need to add a little more equipment and a lot more knowledge and I will be set!
Let me clarify my AP comment.I mentioned it more as a qualifier for what a new mount should be capable of. If i were to invest in a new mount I would like to have AP capability. Someday I may actually have time to explore that part of the hobby.For now it will be just viewing.
So what is it I need? I see the cord is readily available but is there something I'm missing? A control box? Some sort of regulator?

#12 rdandrea

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Posted 22 August 2013 - 09:52 AM

So what is it I need? I see the cord is readily available but is there something I'm missing? A control box? Some sort of regulator?


For visual, if the motors are working, just the power cord.

#13 tim53

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Posted 22 August 2013 - 10:41 AM

Even for AP, all you'd need to add is a drive corrector and dec motor. Especially for planetary.

For DSOs, the camera and guider gear is likely to cost a few $K, so factor that into your future goto plans.

The old spur gear drives are surprisingly accurate. For hoots once, I measured the PE of a few of my mounts. The orange c8 I had at the time had an error of about 22 arc seconds. Of course, it was erratic, not periodic, but that's still amazing for a spur gear drive. For comparison, my Nexstar 9.25GPS has a worm gear drive with a periodic error a bit worse than 22 arc seconds. In addition, the error is rather jumpy, with spikes as bad or worse than the spur gear drive. Of course, the 9" has PEC and an autoguided port, whereas the 8" doesn't. Still, you'd have to invest in two cameras, a guidescope, and probably a laptop for controlling everything.

If I were starting out, I'd first learn what I can do with my existing setup. You can spend months playing with the c8 and a webcam or piggyback dslr (or even slr) before you run out of interesting targets, or the rest of your life if you discover you enjoy the capability and simplicity of a basic system.

Tim

#14 orion61

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Posted 23 August 2013 - 12:09 PM

Since you are new to Astronomy, I would learn to "crawl" before you try to "run".
Learn the basics like rough Polar Alignment, Learn the Constellations, and where larger brighter objects are.
Download the information for the Kochab clock,
(Google this and everything will be explained)
Also learn "How to Collimate a Schmidt Cassegrain telescope.
Your scope is capable of opening a World of wonder for you and your Kids. You have the perfect scope for User Friendly,
"IF" you do your homework before using. I have seen so many people, some in my own Family get frustrated by purchasing a scope, taking it out at night, pointing it straight up and expect to see Hubble like images. When all they see is Stars they get frustrated.
One thing I can promise you is we will all "bend over backward" to help you learn to enjoy the Hobby.
I believe I speak for everyone here when I say, we are here to help our new members avoid frustration, and remember no matter how silly a question may seem to you, we have all been there and are thankful to the folks that spent time with us.
Larry

#15 Glen A W

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Posted 23 August 2013 - 02:28 PM

Seems funny that the C8 is not considered a prime AP scope, since it was what everybody lusted over for AP when I was young. Get a focal reducer.

The newer C8s are not as good. They are cheaply made and the focusers are coarse on some of them. The ones from the early 70's up until the early 90's suit me much better. It would be worth it to get a decent mount and switch it over if it suits you. I do not agree that the CG-5 is inadequate. I use a Vixen 10.4 on one just fine, for AP and just about everything you could do with a scope. There is a big difference between a perfectly usable scope/mount setup and one you can lay your tired head on at 3am without shaking it!

Good luck with that scope. Glen

#16 terraclarke

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Posted 23 August 2013 - 04:31 PM

I know someone else who is getting herself a new/old vintage orange tube C8. Should be arriving in a week or so. :flower:

#17 tim53

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Posted 23 August 2013 - 04:37 PM

There's one in astromart auctions right now. I know the seller, so I shouldn't be the one posting about it.

-Tim.

#18 terraclarke

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Posted 23 August 2013 - 04:39 PM

Mine is "in the bag" (or the packing crate) as we speak. I'm pretty stoked. Always wanted one. By the way Tim, it was your thread on Tinky that made me take the plunge. I had been looking for a nice early one for the past year at a reasonable price, and when I looked at how beautiful your restoration job was, I said to myself, I have to have one, and weirdly, one came up the next day and I jumped on it. It appears to be in very nice shape too.

#19 rdandrea

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Posted 23 August 2013 - 07:53 PM

Mine is "in the bag" (or the packing crate) as we speak.


Are you sure? It has at least two mirrors. Maybe three if it has a diagonal. Are they all in your purse?

#20 terraclarke

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Posted 23 August 2013 - 08:09 PM

:waytogo:

#21 bremms

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Posted 23 August 2013 - 09:14 PM

Gotta have one C8 in the stable. I'm partial to the sandcast after the fuzzy suede paint. Congrats Terra!

#22 5RNS

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Posted 23 August 2013 - 10:46 PM

Update.....
I'm set to order the power cord I need. Then it's off to put some of the stuff I have learned recently to use. Big thanks to orion61 for tutoring me along via PM's.
I've actually owned this scope for nearly 15 yrs. Little did I know what a wonderful scope it is, I have a new found enthusiasm for it and can't wait to give you guys an update once I get going.

#23 terraclarke

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Posted 23 August 2013 - 10:47 PM

Thanks Marc. I thought the same thing. It's supposed to arrive next Thursday. Pictures will be forthcoming.

#24 Datapanic

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Posted 24 August 2013 - 12:07 AM

I've been scouring the forums looking for info to help me make a decision on whether or not to trade in my current scope. I have a C8 with the special coatings I believe. From another thread here it looks to date near 1980. Serial number 803100 .
It has the standard tripod and a wedge. I don't have any motor control equipment but the scope is fitted with motors. Obviously this puts me in manual mode for viewing.
So my delima is now that I'm interested in AP and having a scope that tracks so my kids can enjoy the sky without loosing an object every few seconds, is it time to let this one go?
My budget won't afford me any more aperture, but is a newer scope of the same size a better performer? Is this scope worth investing more money into with a new mount?
Looking forward to your opinions.


I would hold on to it as it does make an excellent AP scope, even without a lot of gizmos to bring it up to current standards. After all, people were taking great film photos with C8's 30 years ago way before digital cameras and autoguiders came into play.

The picture below of M13 was taken with a Canon T3i at prime focus with just a clock drive running for about 20 seconds through a Cave 8" Newtonian - no other guiding. This should give you an idea of what the C8 is capable of doing.

Resale values of 80's C8's are kinda low, so once again, I say hold on to it and see how far you can take it, then get something BIGGER!

Attached Files



#25 orion61

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Posted 24 August 2013 - 03:51 AM

Hi Terra:
I always knew you would slip to the Dark side,
Glad to see you venture in the CAT Family.
I cant wait until we see your first impressions.






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