Celestron 80mm Fluorite Apochromat
Posted 09 September 2003 - 07:33 AM
I have a small telescope that I am in a position to get. I have a chance of getting an 80mm celestron refractor for about 400$. This may seem expensive, but it is because it is a fluorite apochromatic. I did a bit of researching and it seems that Celestron made these in the 80s. The problem I have deciding whether to take it. It does have a couple of problems,
1) The lens element is very slightly dirty. Can I clean it as a one time clean. Other than that the OTA only has a bit of dust even on the inside, and that can be taken care of easily.
2) I'm thinking wether this would be better or would it be a better idea to get a 5" or 6" achromat. I'm slightly interested in deep sky, but not mainly deep sky stuff. However some deep sky would be nice once in a while.
So what I'm basically asking is, how much better is a 5" or 6" achromat than a 3" apochromatic..? Another downside to the larger scopes is the portability. But I want to know if a 5" or 6" will be a lot better than an 80mm apo..
Posted 09 September 2003 - 11:10 AM
First, $400 for an 80mm Celestron refractor made in the 80's - that seems a bit stiff to me. I don't hold Celestron in very high regard relative to their refractor products (they have them produced in China - or Japan if you're lucky) and would doubt their "APO" claims. Be careful here, but remember that I don't know which scope you are talking. Check out Astromart......a brief search of the archives showed a lot of 80mm Celestron scopes (mostly f5 but a few longer f-ratios) all different ages, and all were under $250 most well under that. BEWARE - make sure you know the fair price of what you are being offered and ask if you are new to this hobby.
Dust on the lens - normal and not a problem (assuming it is just normal stuff that collects on a surface opened to the environment). What is more important is how you would go about cleaning it. Be careful because there is more damage done by cleaning than by the dust you are trying to remove. Ask if you don't know of a good lens cleaning procedure. Dust on the inside???? - of the tube or the lens? If you feel comfortable removing the lens cell to clean, this would not likely be an issue - but it does bring another question to mind - just how dirty is the OTA? If it is just normal dust, I don't see a problem with any of it. If it looks like it was improperly stored - I would not touch it. Other than that, I don't have any personal experience with Celestron refractors, and this particular scope is unknown so I can't comment on it's performance.
3" 1980 vintage Celestron "apo" compared to 5" or 6" achromat - that's not hard to define the pros and cons here - but a choice would depend on which 5" or 6"scope you are thinking about and what the primary of the scope would be. The little 80mm is going to be smaller (what is the f ratio of that scope?) and easier to use (of course). If this is your first scope, that is a big consideration. You didn't mention a mount.....do you have one already? A 5" or 6" achromat is a LARGE instrument - bigger than you would ever think. That is a major consideration as the mount could cost a lot, and the scope becomes very hard to set up and use. But for pure preformance there would be no comparison - almost 2X apeture wins everytime!
If you want more aperture than an 80mm - what about a nice DOB?
So there are some thoughts (lacking enough data to really help).......have fun!
Posted 09 September 2003 - 11:20 AM
Ill tell you APOs are nice all around scopes for the moon, planetary, and double stars, especially in the larger sizes. 80mm is kinda small for DSO observing unless it has a low fl like 4-5 maybe? You can get a nib 80mm from Orion all squeaky clean with a much nicer focuser for about the same price if your willing to wait a while if 80mm is really what you want. Ive used the smaller refractors they are nice but 80mm is 80mm no matter how you dice it up. Only advantage the APO has over the achro of a similar size is no color at higher mags but small objectives give lower contrast fast verses a larger lens. You mentioned being portable, yes, thats the usual gripe with larger refractors so thats up to you. I can tell you that a 5-6" refractor blows away a 80mm APO if it has a violet filter attached and you can get them for about $400 but they weigh about 26-30lbs and are big. The 80mm sized refractors are great daytime scopes tho as aperature dosent matter much then. For $400 id go with the new Orion myself if thats the size I wanted period. Plus the lens coatings are newer and may be better as well. Dave
Posted 09 September 2003 - 11:25 AM
Posted 09 September 2003 - 11:48 AM
Posted 09 September 2003 - 01:32 PM
I guess 400$ is a bit high for this, I'm still haggling and may get it for even less.
I know that a 5" or 6" achro woth a MV-1 filter would be fabulous compared to a 80mm apo, For one thing, portability is pretty important to me. I can get a 6" achro cheap at anytime, so I'll keep it as a second priority for now.
Oh well, I'll just try nd get the price down and if I don't I'll get a 6" achro. He's almost willing to give it away. Who knows maybe I can convince him to donate it to our astronomy club..!!
Posted 09 September 2003 - 01:37 PM
I guess 400$ is a bit high for this, I'm still haggling and may get it for even less.
It may not be the right scope for you, but the price is right. It should be a notch above a TV76 and you won't find one of those for $400!
Posted 09 September 2003 - 02:38 PM
Posted 09 September 2003 - 02:55 PM
That 80mm scope WOULD make one heck of a viewfinder on the 14" of yours wouldnt it! Put a crosshair eyepiece in it and WOW! Hahaha!
Posted 09 September 2003 - 03:28 PM
That 80mm scope WOULD make one heck of a viewfinder
Careful; them's fightin' word to the refractor wienies!
Seriously; I've never owned a really good 80mm refractor and would like to try one. I've used the TV Genesis piggyback but it's a little big and heavy for that. I've been looking through my Nexstar 80mm lately and it's nice but not as nice as my old 80mm Vixen ED. An APO would be great. Besides, if I get an 80mm APO I won't be as tempted to consider a bigger one whenever I see pictures of Charles' excellent Tak.
Posted 09 September 2003 - 04:40 PM
Yes Charles does have something I would very much like to own myself, its only money afterall,we should both buy ourselves one really..... and soon,............someday we both will be dust and it wont matter anyway.
By the way, I havent heard much from him lately ever since he bought the TAK, ya suppose he could be suffering from insomnia?
Posted 09 September 2003 - 06:19 PM
I wasn't aware that Celestron brought in Vixon APO back then.....that might just be an interesting scope. Better than the more recent stuff I saw on Astromart. If the mount is included, it could be really nice. Do you know which mount they came with John?
Sounds like there may be another "wienie" born here......
Posted 09 September 2003 - 07:44 PM
Posted 10 September 2003 - 12:07 AM
I cant go smaller like you fellas are considering, size matters to me, hehehe..................
Posted 10 September 2003 - 12:15 AM
Posted 10 September 2003 - 12:16 AM
Posted 10 September 2003 - 11:02 PM
Posted 12 September 2003 - 06:47 AM
at 400$ I think it was a steal. we took it out for Mars last night. no false color on the moon, and an absolutely stunning mars..!!
Posted 12 September 2003 - 08:09 AM
my lil baby blue beauty is a Brandon 94mm with the Rowland AP triplet lens. It has a FANTASTIC sharp flat fov and pinpoint stars! Ive pushed its mags as high as my 8" schmidt and Mars was clearer in the lil 94mm just dimmer!!!
I never thought such a small aperature could do that....It was made back in 1990 I believe and is still in almost mint condition like it was bought this yr. Ive got a all wood handmade carry case that was custom built for it as well, heck the foam lined case is so sweet it was the deciding factor when I purchased it as I needed a transport case anyway. I have pics if you want to see it, its mounted on a Meade LXD55 for stability. Dave
Posted 12 September 2003 - 06:33 PM
I do love my refractors, but I'm really thinking it needs a partner to handle the fainter DSO imaging. I've been thinking adding about a 8-12" Mak-Cass to the stable for those hard to reach objects.
Look forward to the image of that little beauty!
Posted 12 September 2003 - 06:55 PM
Posted 13 September 2003 - 11:22 PM
I'm getting rid of the STV to get better remote/scripted guiding capabilities with an ST-237 - and it seems like everything else is changing too. I haven't even thought about what it will take to buy the Mak-Cass. I wish my kids hadn't grown up, I'd likely sell one (or both) of them right now
Posted 14 September 2003 - 08:26 AM
Posted 14 September 2003 - 01:33 PM
22 miles is duck soup! I wish that is all I had to do. I'm looking at 60-70 miles - so it isn't done very often at all. Driving ain't fun anymore. Certainly agree with you on the driving part. When I retire I want to be in dark skies.
I've wanted to buy a conversion bus (old GMC Greyhound or something along that line) so use for dark sky visits. That way everything I need stays in the bus so I don't forget anything - coming or going. Even the kitchen sink. But the wife is a hard sell. Sigh.
Turns out the bus can not access some of the sites I go to beside the road drops off so fast it'll high side - litterly stick to the road. But I still think the idea has some merit. Just need to iron out the wrinkles. Get some money. Money seems to be a bigger issue than dark skies - no kids to sell and all. Not too sure if my gene pool would be worth all that much anyway.