Quote:
Originally Posted by cventer
What about a Tak TOA 130 and use the change to buy a decent CCD and Filters.
Those Hiper Apo's sure look pretty though.
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I think that is definitely worth considering! Thanks for the suggestion cventer
Quote:
Originally Posted by strongmanmike
Italia vs Nippon...tough contest 
You would be deciding between supermodels  so can't go wrong either way!
Mike |
Always hard to decide when making a purchase for astro work. Thanks for the input Mike.
Quote:
Originally Posted by gregbradley
Not that tough I suggest. .96 stehl is high but others are better. TEC makes to .99 strehl in green so does AP and I suspect so does Tak TOA130.
There is a question mark in my mind about using carbon fibre for a refractor. Roland Christen the acknowledged master in this game is against it because of tube currents. No doubt that is why they have fans. You've gotta wonder of those fans over time could enter dust onto the back of the lens. Carbon fibre is light and that would make it easier to mount the scope on a smaller mount though. Zero tube expansion is not as important with APO scopes as the lens shift focus anyway with temp and aluminium follow that to some degree. I'd be interested to hear from anyone using a carbon fibre tubed scope about stability of focus with temperature drops.
The lens appears to be a LZOS lens and they definitely do make good high end lenses but certainly not best in world. They are Russian.
The sample images they show on the website are terrible and one shows bad chromatic aberration so not a good ad for their scope.
AUD$11,000 for a LZOS 130mm scope is really poor value for money and I doubt you would ever get that back in resale. You'd probably only be able to get $4500 - 5000 max for a 2nd hand 130mm APO at a guess and for a not so well known brand not even that.
A TOA130 often goes for about US$4500 on Astromart 2nd hand. That would be about AUD$6000 or less in Australia (depends if you are charged GST or not on 2nd hand scopes, about $600 for shipping).
For $11,000 you could get an AP140 with reducer/flattener, a TOA130 with a camera or a TEC140 with flattener and a camera. Plus your resale value would be 10-15% off what you paid for it or the same if you buy well.
I doubt this scope could keep up with a TEC140 let alone an AP140 or an AP130 GT. I also wonder how good the reducer is. Reducers often give coma in the corners on full frame sized chips. A 3.5 inch feathertouch is nice but the TEC scopes all have those for far less. AP's 155TCC and Taks super reducer are the only reducers I am aware of capable of round stars to the corners of a full frame sensor. APM claim they have one but it is new and no examples to show proof.
By the way I find it annoying when scope companies falsely promote fluorite lenses. This is definitely not a fluorite lens - only TEC make those at present. It is Russian OK4 which is the equivalent of OHara FPL53 glass which has a lot of fluorite in it. A fluorite lens is the best in the business and costs a lot and not made by the Russian LZOS company.
it is a single crystal built up of Calcium Fluorite and is not a glass its a crystal.
It is a common scam marketing hype to fool customers as is the term hiper APO - no such word. There is hype APO hehehe. There is a definition for super APO but that is 4 colour crossings at focus at the same time and this scope nor any of the above achieve that. TEC, AP and Tak would come close.
There is no way that scope would match this 2nd hand AP 130 F6 and its half the price. Ask Peter Ward:
http://www.astromart.com/classifieds...fied_id=749922 AP130 $5000
Greg. |
Firstly let me say thanks for taking the time for this detailed reply, Greg. The information is fantastic. The reason I was leaning towards Officina Stellare is because the information I was given was that they are the only one of two suppliers that does a genuine triplet fluorite on the market, the other being TEC. Taks were also mentioned and it was noted that TEC would be as good as OS and the Tak slightly behind the two. As you have worked out I am looking for a very high end refractor and just want the best setup I can get with the current budget. I would like a TEC or AP but I am a little nervous about the 2nd hand market in that I am worried about the quality of the optics (scratches) and shipping. This is another reason that the OS refractor was appealing considering I could pick it up new from a local dealer BUT if the initial quality is not there then I would prefer something else.
If I could pick up something with a Strehl of 0.99 then I am there! I think after reading your post I am definitely rethinking my options. I would like to get something fast and flat so I will be looking very closely at your suggestions an definitely the reducer/flattener as it would be critical. Next I could search for a really nice CCD. I have read your post regarding the new Kodak sensors which sound great but as usual with this hobby , if it sounds great it costs $$$. My thinking is now starting to head towards a nice 0.99 strehl TEC or AP (if I can find one) and then start investigating CCDs.
Your input has been greatly appreciated and if you have anymore suggestions to add pease do! I would be interested in your experiences with second hand purchases.Thanks again
Regards,
Lucas