Quote:
Originally Posted by gregbradley
I agree with Mike a TOA150B with flattener and reducer and Q extender is hard to beat in the refractor game. See Marcus Davies images on this site. He has shown consistently more detail in his images than I thought a 6 inch APO could show. Expensive though.
AP155EDF is the other one that is about the best there is. Especially with the AP reducer/flattener (155TCC). They come up occasionally usually for about US$9500 although there was one recently that went for a lot less. But it was quite a bit older and had the 2.7 inch focuser - you really want the 4 inch focuser. 2nd hand TOA150's when they do come up (not that often) usually go for around US$9000-9500. They used to be about $9000 new in the US now they are $11,400 at optcorp.com! I guess the Yen has appreciated against the US$ and there nust have been some price increases.
If I were shopping for a 6 inch APO my list would go like this:
AP155 with 4 inch greaseless focuser and feathertouch microfocuser and 155TCC reducer/flattener and 4 inch flattener.
TOA150B with flattener, super reducer and Q extender.
TEC160FL with flattener and new rings (ditch the TEC ones they damage the scope).
And thats it.
What mount are you looking at? For a scope that size the Paramount MX is probably the one to get.
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I would love a Paramount MX and all three of these telescopes would be fantastic but unfortunately I only have an EQ6 Pro, which I can autoguide well up to FL 1000mm but the weight of these scopes is probably too much. I am in a position where I don't have an Obsy set up and have to pull things up and down when imaging. I will be moving in the not to distant future and will be able to get an obsy happening which is when the Paramount MX will be the mount of choice and so will the 6 inch APO!
Quote:
Originally Posted by strongmanmike
If it were me Lucas (and I didn't already have an AP152EDF) I would bite the bullet and order a brand new Tak TOA150 with flattener, extender and reducer 
Mike |
It really sounds very appealing and versatile. It would be a great option definitely for the future when I upgrade to the heavier payload mount. You must love that AP152EDF. I know I would!
Quote:
Originally Posted by Hagar
Hi Lucas, My choise would be to look at the Tak 130. At the price it is hard to beat. Roland Christen has even stated that the TOA 130 is the best colour corrected scope on the market. Thats a big statement from him. For what it's worth with any of the triplets mentioned you will undoubtedly need a field flattener and you are better to buy a scope which has one made for it. Tak scopes all come from the factory with a Strell of 98 or better. Just be aware that all these scopes are quite heavy, the TOA 130 is around the 11 to 12 KG mark and can be purchased with either the 2.7" focuser or the big 4" focuser at extra cost.
I looked very hard at the 130 but ended up buying the 120 based on weight concerns and cost. I might add I am very happy with both the 120 and FSQ I own. Tak may be almost mass produced but they are up there with the best.
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Thanks for the input Doug. I think my EQ6 Pro might be a little light on for imaging (I could always have a crack!) but these TOA Taks are definitely in the mix considering all the accessories available.
Quote:
Originally Posted by gregbradley
TOA are awesome scopes.
Keep in mind 2 things when considering these high end scopes to help differentiate between them. One, the availability of accessories. Tak has a very full range so does AP. TEC makes a dedicated flattener but no reducer. The Tak or AP may work on it but it may not. I have a 4 inch Tak flattener and a 4 inch Tak reducer meant for the FS152 (a doublet) and the flattener works on both my AP140 and my TEC180. But the reducer only partially works on my TEC180 with some star distortions in the corners. The more recent Tak super reducer may work on it but its a US$2200 item.
Also when buying a Tak scope the price includes nothing but the scope. No mounting rings, no finder scope, no mounting brackets for the finder scope, no dovetail plate etc. So add another $800 for all that.
That puts the Tak 150B in the same price league as a TEC160FL.
Hmm there's an interesting shootout. Which is best - TEC160 oiled fluorite triplet with 3.5 inch feathertouch focuser (or now its a proprietary TEC focuser also available with built in electronic focuser unit)??
As a TEC fan I would have to say an oiled fluorite triplet would be hard to beat. Even Tak would agree as they make one - only they want 3X as much as TEC!! But it would be close and perhaps not a lot in it apart from accessories. I would go the TEC myself but that's just me. A custom fluorite oiled triplet will no doubt no longer be made within a few years given the way this industry goes and these scopes will be the AP's of the future in several years. They are already highly prized and the supply of exotic glasses needed for the lenses are already becoming hard for TEC to get. The TEC focuser is excellent as I have a TEC110FL and it is the proprietary TEC focuser and I would rate it as equal to the Feathertouch and perhaps better in some ways. It is better than the Tak competitor focuser.
The 2nd point is these extras are very expensive. A 4 inch flattener is around US$2200 for AP and Tak. A TEC one is US$750 and it works perfectly on a 16803 chip (the current ultimate test).
The Tak extender also works on the TEC as I have used one on my TEC180FL with a Q extender 1.6X and a special custom adapter giving F11.2 and a FLI ML8300.
Tak and AP have more accessories.
The other factor is availability.
AP is only available 2nd hand.
TEC currently have glass for TEC180FL (2 left) and 140ED models. The 160FL not until next year at the earliest. They already stopped prodction of the 200 fluorite, the 200ED and the 160ED due to glass supply problems. So you see my point about these high end scopes.They are destined to be classics.
Tak seems reasonably available although perhaps a wait for a 150B, yu'd have to shop around.
Tricky isn't it?
If you wanted to take a punt (and it would be a punt) Markus Ludes was selling a 150mm APO from China that he claimed was finally as good or better than the top guys. He sells the APM/TMB scopes. He's a bit of a shark but he does sell good gear. I got some custom rings off him for my TEC180. These scopes were US$6995 or so which is cheap for a high end 150mm APO. Leaves money for a nice CCD like a KAF8300 chipped camera or a 11002 chipped camera.
decisions decisions. Not an easy task wading through all this data making a choice of which scope.
The bottomline though is any of those top 3 brands is going to be an awesome scope and the differences are much smaller between the 3 than between high end and lower end.
6 inch APO is the sweet spot for astroimaging. So is about 1200mm focal length. Mike's AP152 is the perfect focal length in my opinion. WIth its flattener I think it was running a little longer focal length and it works out beautifully for many objects. I personally feel F5 is also a sweet spot for imaging if you can get it. So a 6 inch APO, around 1200mm focal length (not that vital, 1000mm would be fine) and F7 with the ability to go to around F5 is what you want. TOA150 is quite versatile in that regard. AP also, TEC can be made to work probably with a bit of research to get to F5.25 (the new APM reducers may do the job for example, they are US$700 + the inevitable adapters $250 +).
My final point, a high quality 6 inch APO with accessories and a good mount with a good camera will last you a lifetime in this hobby. The 6 inch APO is not in danger of being outperformed by some new and exotic design in the future. There will be far less gain upgrading to a larger APO. A 130mm (as good as they are and they are good) may have you wanting a larger scope later and you will lose in the selling/buying process especially if you bought a lighter mount for the 130. Always factor in aperture fever and the costs associated with that. I read recently that the jump from 140 to 160mm is the biggest noticeable jump in APOs visually. Budget rules though at the end of the day.
Good luck with your choice.
Greg.
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Greg,
You have been extremely helpful in this refractor project and the wealth of information is priceless. I too like the idea of the oil spaced triplet fluorite. The TEC140 would be great as it is a good weight for my EQ6 Pro but being ED glass (which is still nice) I would want the fluorite so I think the TEC160FL would be my first choice there. The TOA Taks are definitely being considered, wonder if I could mount a TOA 130 on the EQ6 Pro? Astrophysics would be fantastic also. At this stage I think I would have to go for a refractor that I could mount on the EQ6 Pro until I could upgrade my mount. As I stated earlier I'm in the pull everything up and down category until I move and build my Obsy.
Decisions, decisions....
I think it's a bit like real estate in a way. When the right scope comes up with the right deal that will be the time to buy. With the strong dollar against the US, Astromart is an attractive proposition. Especially considering I am partial to an AP but just thought they were too hard to get.
Regards,
Lucas