Just an FYI for anyone in the market for a new Celestron 6" F/8 Achromatic Refractor OTA, Bintel are currently having a sale where you can get this OTA for only $599!!!
If you're after a new one, what a bargain!
Adding a Bintel (GSO) dual speed focuser, a Bintel quartz diagonal and a Baader fringe killer would make this quite a nice telescope!
.. and a Baader fringe killer would make this quite a nice telescope!
Cheers,
Mark
Nope, it sure doesn’t. Still swimming in colour. Owned one once and Brian loaned me the filter and this telescope still puts up loads of purple. I wouldn’t recommend the telescope except as a solar scope after conversion(which is what was done to mine by the buyer)
Its ok to start.
It boils down to $600 and get a refractor that size with colour issues or spend min of $6000 for the real deal.
And that probably means for many having something or nothing.
I got one years ago and for starting out was terrific.
I didnt mind the colour and it was not until I tried to photograph with it that I saw the colour as something that I could not live with.
The sad thing was when I bought mine it cost $2000 on a crap mount.
Best value in my view is the eight inch newtonian great for photos at this stage and great for visual...reasonably priced.
I actually prefer the eye piece placement of a newtonian.
Alex
Thing is Alex, the optics are only fair at best. I saw more detail in a Vixen 102mm doublet than I saw in the "Dinosaur" (as my daughter called it, when covered in a sheet on the mount). The views are NOT precise, nor particularly spectacular, plus the violet blot makes it very distracting to use - not enjoyable at all.
Sure, it shows more, but less precisely than a good doublet of smaller size.
Thing is Alex, the optics are only fair at best. I saw more detail in a Vixen 102mm doublet than I saw in the "Dinosaur" (as my daughter called it, when covered in a sheet on the mount). The views are NOT precise, nor particularly spectacular, plus the violet blot makes it very distracting to use - not enjoyable at all.
Sure, it shows more, but less precisely than a good doublet of smaller size.
I agree if I was spending $600 I would not buy one but go for 8 inch reflector.
Still mine gave reasonable views but I was not educated and did not know what I was missing.
It now sits unused.
Its like most things if you want good you pay.
I love my little 80 mm by the way and am starting to wish that I had gone 4 inch... 6 inch would be too big for me.
When I get out of Sydney I intend to get a good 6 inch refractor, the espirt probably, when I can set up permanently in a shed or a dome.
I have thought of using the old 6 inch refractor as a scope to look at terrestial stuff...I have an erecting prism someplace.. and leave it set up on the patio..its worth little now..maybe $200 so that would be ok.. I did notice you mention a solar scope out of it...thats interesting I may look into that.
You have to keep this in context. We are talking a $600 6" Refractor. You cannot compare it to a $7000 Esprit 6". It's like comparing a corolla to a mercedes. Have you tried double stacking with a Baader semi apo?
Newtonians are very affordable but the diffraction spikes in images are annoying to me. Just a personal preference, some people like them. I like astro images to be more accurate representations, not flooded with unnecessary optical artifacts.
I had the pleasure of spending 3 nights recently with my mates Skywatcher 190mm Maksutov-Newtonian - now THAT'S a telescope! Massively overlooked by people. Perfect pinpoint stars across the entire field, simply AMAZING views. No diffraction spikes, beautiful pinpoint stars. No coma or field curvature. Very sharp. Wide field but fully corrected, Apo performance for a fraction of the price.
I'm going to be getting one of these SW Mak-Newt's on a Celestron CGX mount which I prefer. I like the planewave software with the CGX, and when i spent time with the cgx in the field, it and me just 'clicked'
I would recommend anyone looking for large aperture APO performance at only the 2K mark to go and experience the SW Maksutov-Newtonian.
One has to remember these are only cheap scopes..they have their problems...F5 Aspheric was good on DSOs etc .though still needs filtering ..got a good one perhaps.
Can NOT compare to a good ED or Triplet for colour correction, or focus of colours..you WILL see MORE Planetary detail and go deeper..and be able to do long exposure deepsky AP.
What it will do, is give you a taste of big refractors on visual deep sky mostly.
These scopes vary a lot in lens quality ..some good , some aweful..its a lottery as with SCTs.
Never tried this model, has only a normal achro lens...some can tolerate the purple flaring on objects... others not so..focusers ..aweful!
If you already have Reflectors, SCT etc.. buy cheaply and try it , if you really must..sell it if not to your tastes, its up to you.
Better still wait and save up for an ED Or Triplet of 4" or more.
bigjoe.
Last edited by bigjoe; 21-02-2018 at 05:06 PM.
Reason: Adding
I don't understand the complaint about the weight of this tube... It is 12.5kg (OTA prior to adding accessories). 12.5 kg! I've moved my mate's around several times. Perhaps it is easier because I am in my thirties and athletic, but 12.5 kg does not seem at all heavy in my experience. So the weight is a total non issue for me. Nor the mount I will be putting it on.
If lifting a pot plant is a challenge, then yeah, stick to something very light. Or just work on some baseline strength perhaps.
Cool down - the rear of the cell can be removed and an extraction fan added if need be. I am of the view that the benefits of a closed tube far outweigh the downsides. Much longer life mirror coatings, no influx of currents once cooled down, reduced stray light, dust is a non issue, and goodbye to secondary mirror arms which introduce annoying misrepresenting diffraction spikes during imaging and can never match the pinpoint star views in a telescope without the spikes, plus lower contrast.
Dew - this is the same problem faced by any telescope with a front corrector lens - schmidt cassegrains mostly. Astrozap make a dew shield for this model. Dew is not really an issue here anyway. Location dependent i suppose. For me this is more about preventing stray outside light onto the corrector and avoiding any accidental touches.
At the end of the day it comes down to a degree of personal preference however the optical performance is A+ hence I have no hesitation recommending this optical design. I personally love Mak-Newts!
I'm not "refractor guy", perhaps put me down as "Mak-Newt guy" haha
Regards
Mark
Quote:
Originally Posted by LewisM
I owned one of the SW Mak Newt 190s...all I can say is research WHY they are overlooked.
Give you a few clues: weight, cool down, dew, dew, dew, dew oh and weight
I don't understand the complaint about the weight of this tube... It is 12.5kg (OTA prior to adding accessories). 12.5 kg! I've moved my mate's around several times. Perhaps it is easier because I am in my thirties and athletic, but 12.5 kg does not seem at all heavy in my experience. So the weight is a total non issue for me. Nor the mount I will be putting it on.
If lifting a pot plant is a challenge, then yeah, stick to something very light. Or just work on some baseline strength perhaps.
Cool down - the rear of the cell can be removed and an extraction fan added if need be. I am of the view that the benefits of a closed tube far outweigh the downsides. Much longer life mirror coatings, no influx of currents once cooled down, reduced stray light, dust is a non issue, and goodbye to secondary mirror arms which introduce annoying misrepresenting diffraction spikes during imaging and can never match the pinpoint star views in a telescope without the spikes, plus lower contrast.
Dew - this is the same problem faced by any telescope with a front corrector lens - schmidt cassegrains mostly. Astrozap make a dew shield for this model. Dew is not really an issue here anyway. Location dependent i suppose. For me this is more about preventing stray outside light onto the corrector and avoiding any accidental touches.
At the end of the day it comes down to a degree of personal preference however the optical performance is A+ hence I have no hesitation recommending this optical design. I personally love Mak-Newts!
I'm not "refractor guy", perhaps put me down as "Mak-Newt guy" haha
Regards
Mark
Seems you have all the answers as previously, so again, wish you good luck! Some have experience directly with what you are interested in, so I'd take a LITTLE notice instead of dismissing it.
Yes, the MN is a good scope. The fans help SOMEWHAT, but mine - with fan - still used to take 2 hrs minimum to come to an acceptable level for VISUAL (certainly more for imaging).
Dew - Astrozap didn't do squat for mine. What I had to do was a dewshield extension AND an astrozap running at full tilt. And it still dewed on most nights. Worse than a Mak or Cassegrain, likely due to the mass of the glass of the corrector and it's associated thermal retention factor.
Focusers on these are also crap. Don't hold a large EP well, let alone a camera. Need replacing - more $$$.
Weight - 12.5kg is not much, at the start of the night. Wait till after a long session then taking it all down. Less fun. I have no issue with weight, but... permanent setup is a good idea with these like Glend's setup using one. No weight issue then.
You'll also need rotating rings for best use.
Collimation can be a right pain on these - worse than an SCT. Yet to see one spot on yet - mine was always out after moving it, as was the mate I bought it from (his was too - he never stopped fiddling with it). Probably have to change mirror springs.
Everyone gets excited about Mak-Newts until they own and use one for an extended period of time. They can be VERY good, but they can be a right pain in the arse too. Glen loves his (I think), I liked it for a while.
Not all of us can go out and spend 5-10k on an APO that gives you bragging rights over those ( like me and you , and many others ) that cant afford that much , ( worth more than most people's car's ) so lets stop with the ' BAGGING ! of a great refractor that gives many their first taste of BIG ! ,,,
,,, refractor heaven at a very good price ! .
Jeeze some people just cant help themselves ! . Can they ? .
I feel sorry for any beginner reading this that aspires to a 6 inch refractor and believes that these are rubbish because of a little CA ! BAD ! .
I have one a Saxon version that I have put side by side with an Astrophysic's 152mm f12 ' Starfire Planetary ' and the owner of that scope was gob smacked at how good a $1000 achromat was against his 10k APO ! , yes that's what I payed for mine , OTA only and still have it it's in NZ being used by my Nephew .
Brian.
Quote:
Originally Posted by AstroStudentUSQ
Hi Lewis,
I myself also have first hand experience in the field with this model. That is why I am so impressed by it.
It sounds like you got one made on a friday afternoon before a long weekend!
Thank you for your input, I will take it on board.
Cheers,
Mark
Last edited by brian nordstrom; 21-02-2018 at 09:21 PM.
My comment that you quote was in regards to my later discussion on this thread about Sky-Watcher's Maksutov-Newtonian. Sorry, the thread evolved a bit away from the original C6R discussion.
I'm happy for you that you got a good C6R. Many forums have users talking about how the C6 Refractor is either, i. bad; ii. average, or iii. great/fantastic. There doesn't seem to be consistency in quality control with the production of those so it's great that you won the telescope lottery in that instance and got a good one! It should be noted however that consistency in quality control is not guaranteed for even very expensive instruments. I have read reports of even Losmandy mount f*ck ups.
Certainly at that price point, keeping it in perspective, at a minimum it would make an interesting project adding/evolving parts for fun to see how good one could make it.
As you mentioned it shouldn't be dismissed as a beginner telescope either. My first telescope was for my fourteenth birthday and it was a Tasco 76mm 700mm FL Newtonian in 1998. What would almost universally be condemned as junk by many. But my particular one is fantastic. Must have been made with enthusiastic employees with an abnormally high quality wave of components. In 20 years the mirrors have only degraded very minimally, the aluminium tube is still great, the focuser, although a 0.965 size, is incredibly smooth, I love that little telescope. It provided crisp, clear views of Jupiter, Saturn and M42, and really got me hooked on Astronomy. 20 years later, it sits on my desk as a loved ornament and reminder of my start in astronomy. Now later in life, I am starting the path to become a Professional Astronomer/Astrophysicist through Astronomy degrees with USQ. My point is that such beginner telescopes should not be universally condemned, as some do come through the production line better off than average, and that small telescope gave rise to a new professional astronomy mind later in life. Likewise, the gift of a simple and affordable C6R or similar, may be the conduit to other young minds seeking a career in astronomy later in life.
Best of luck with your refractor Brian! Cheers for your reply!
Cheers,
Mark
I don't have experience with the C6R however I have read Starlight Nights by Leslie Peltier. Mr Peltier used a 6" f8 achromat for years as a variable star observer. The book is good reading for cloudy nights.
Found an old photo of mine back in NZ taken about 12-15 years ago and as you say some are average , some good and some extremely good , this Saxon is in the last category , exceptional optics for mass produced Chinese optics .
Fully adjustable as well and that makes a big difference as these 150mm lens's are very heavy ( BIG chunks of glass ) and will get out of alignment if banged hard enough .
These ride well on an HEQ5 but being long the tripod is always to short for comfort so either an extension pier or a HD Hardwood tripod like mine makes a huge difference , .
Notice mine is nice and central on the mount ? , there is about 1/2 kg of lead fishing sinkers epoxied into the adaptor between the focuser and tube , on that my focuser worked very well from day one ,, strictly visual of course .
Brian.
Last edited by brian nordstrom; 22-02-2018 at 10:44 PM.
Forgot to mention , those white strip's around the tube between the rings are Nylon strips about 8mm thick screwed around the OTA and with the rings set with bolts and lock nuts I can rotate the whole OTA with ease without the worry of the HUGE assembly sliding down and getting really , really out of balance very quickly , bad at 2am in the dark !!. .
Balance is achieved via the dovetail but being a massive OTA it takes only an eyepiece like a TV 31 telemangler to upset the balance .
Seriously, it is not about snobbery whatsoever - if you will recall, I had my C6R even before I had my Vixen FL102S, and you had loaned me your fringe killer for it. Even I in my neophyte eyes could see the telescope was really sub-par, and was actually counter-productive, especially since most - like myself - will UNDER-mount it on an EQ5 (like I did) or similar. The EQ5 really can't handle it, and I ruined my EQ5 using it on it. You need an HEQ5 miniumum, and even then... so, no, there is a price in the cheapness, despite the other factors of needing to replace the focuser, add tube counterweights to balance it in an appropriate position etc etc.
You got a good one - consider yourself lucky.
And my experience with the Mak Newt is relevant. The guy I bought it off - RIP - had the same issues with his as I did with mine, and he was forever collimating it. Really good scopes, but lots of fiddling and frustrations.
Nobody mentioned ' Snobbery ' your word , I mentioned ' Bagging ' a good telescope that most would be more than happy with if that's what you want .
But Lewis that's what makes astronomy FUN ,, fiddling with telescopes , mounts etc. ,,, I seem to remember a nice auto guider mount someone made just recently . mmm and a dairy tube tripod upgrade , that's what it's all about aye mate fiddling and enjoying .
And these scopes at $600 plus another $5-600 for a 2nd hand HEQ5 are awesome for that price and if you broke an EQ5 I would say that's user error as I personally know 2 people with these and 8-10 inch Newt's on EQ5's and have had years of service from these mounts .
Balance is the key as you know now and that's the gist of the OP's starting this thread the good price of these OTA's just now .
Brian .
Quote:
Originally Posted by LewisM
Brian,
Seriously, it is not about snobbery whatsoever - if you will recall, I had my C6R even before I had my Vixen FL102S, and you had loaned me your fringe killer for it. Even I in my neophyte eyes could see the telescope was really sub-par, and was actually counter-productive, especially since most - like myself - will UNDER-mount it on an EQ5 (like I did) or similar. The EQ5 really can't handle it, and I ruined my EQ5 using it on it. You need an HEQ5 miniumum, and even then... so, no, there is a price in the cheapness, despite the other factors of needing to replace the focuser, add tube counterweights to balance it in an appropriate position etc etc.
You got a good one - consider yourself lucky.
And my experience with the Mak Newt is relevant. The guy I bought it off - RIP - had the same issues with his as I did with mine, and he was forever collimating it. Really good scopes, but lots of fiddling and frustrations.
Last edited by brian nordstrom; 23-02-2018 at 07:17 PM.
Me too Mark , this is an absolute Bargain !
.
. Can they ? .
Found an old photo of mine back in NZ taken about 12-15 years ago and as you say some are average , some good and some extremely good , this Saxon is in the last category , exceptional optics for mass produced Chinese optics .
chunks of glass ) and will get out of alignment if banged hard enough .
of course .
Forgot to mention , those white strip's around the tube between the rings are Nylon strips about 8mm thick screwed around the OTA and with the rings set with bolts and lock nuts I can rotate the whole OTA with ease without the worry of the HUGE assembly sliding down and getting really , really out of balance very quickly , 
.
. mmm 
, that's what it's all about aye mate fiddling and enjoying .
