TSA 102 vs. TV 102 ?

[Profiler (Profiler)]

This is probably an impossible question to answer so at the risk of starting WWIII I would simply be curious to know other IIS members opinions on what might prove to be a better OTA primarily for visual astronomy between a TV-102 versus a TSA-102? Or at this pinnacle of workmanship in OTA’s for visual astronomy there really wouldn't be much of a discernable difference

[Kal (Andrew)]

Without having observed through either telescope, I would take the tak. Triplet super-apo optics versus a doublet for the televue.

9 out of 10 days you'd struggle to spot a difference, but on that rare night with exceptional seeing you'd be hard pressed to beat the tak.

[Exfso (Peter)]

I was under the impression that the TV102 was a petzval design, will stand to be corrected on this though. If so it would be on par with the FSQ106ED Tak.
Edit: the TV102 looks like a doublet F8.6 so definitely go with the TAK.

[Profiler (Profiler)]

The TV-102 is, to my understanding, a F8.6 doublet made with TV's own specification glass versus triplet in the TSA-102. I would lean towards the Tak triplet without hesitation for imaging however, in the context of visual astronomy does anyone think the doublet might have some advantage (this was reflected in Ed Ting's comments on the TV102) or perhaps I am just comparing apples and oranges here or Tak "super" APO's versus TV "ordinary" APO (I am being facetious here)

Thanks for the comments already - they are very much appreciated.

[Kal (Andrew)]

There might be some advantages to the doublet with regards to a faster cooldown, but unless you observe somewhere with big temp changes I don't think it is an issue - especially in places like Sydney as it is near the coast. If you were to observe out in the country where there are bigger fluctuations this may be a more important consideration.

[DavidU (Dave)]

This professional test report of a TSA-102 shows just how good these really are.About as good as it gets.
http://translate.googleusercontent.c...qdzQ#post40202

[Paul Haese]

I have owned the TSA102 for quite a few years now. The cool down time is well around 1 hour and that might be too long. The scope presents superb pinpoint stars and it is well corrected. I use it for my primary widefield imaging telescope but every now and then I use it for visual. Lovely piece of craftsmanship.

I have not looked through the TV unit but being a doublet, I would suggest this will be a little inferior to the TSA.

Best of luck with your choice.

[Sylvain (Jon)]

I haven't looked through any of the 2, but I have observed through quality triplets and doublets.
I think my personal choice would be the doublet, for its lighter weight and faster cool down, but mainly for the weight.

You can expect both scopes to be fantastic though
At this level, it boils down to personal preferences I reckon!

[anj026]

I bought my TSA 102 over 2 years ago and have only ever used it for visual. It is a wonderful telescope and I recommend it. At the time I purchased it I considered the TV102 but it was more expensive then. The TV102 comes with a great hard case and an excellent 2" diagonal and the price has come own a bit so for visual it might represent better value now. The TV102 package might be considered more robust also. It has anodized parts and a powder coated tube. The TSA is all painted and slightly more fragile. Ultimately the TSA probably has better optics but for visual the TV102 is right up there with the best. I made my own hard case for my TSA. If you plan to travel a lot with the scope and transport it a lot then the TV102 probably makes more sense. On the other hand the TSA is very well made and with reasonable care can be just as reliable. You can't go wrong either way.

[gregbradley]

I've never owned a TV scope. But a doublet is not an APO its a semi-APO. All doublets are semiAPOs. Theoretically a doublet could be made APO but I am not aware of any that were.

Mind you it is probably a superb semi-APO. But to be fair APO has a definition. It mean s 3 main wavelength colours are in focus at the same time. Not sure which colours but something like RGB (its not RGB but similar). Doublets typically get 2 the same and one fairly close (usually blue/violet). Super APO means 4 colours in focus at the same time. These terms get degraded for marketing purposes.

Visually as eyesight is heavily biased towards green (TEC gets the green at over 99% strehl for this reason) it may seem fine. But image with it, especially a one shot colour like a DSLR and you will most likely have blue haloed bright stars.

One bright objects like the moon or Jupiter you may see a tad of colour a the fringes but not especially objectionable. Otherwise it is hard to notice.

MY Tak FS152 was a fluorite doublet and despite being semi APO it still gave some of the best views I have seen in any scope.

It tends to give a slightly warmer look to some objects because the blue is slightly out of focus.

True APOs may make objects look cooler.

Doublets though are light, cool down very quickly (my FS152 cooled down super fast). The Tak fluorite doublets gave snap to focus images that are very sharp and highly contrasted. The extra contrast helps give more detail in viewing.

The TSA102 from what I have read as was mentioned is about as good as it gets with triplets. I read a post from a guy who has owned about every high end APO imaginable (various AP scopes, TEC, TMB) and he thought the TSA102 was one of the very best in its class.

Tak usually gets all the other parts really right as well.

My main complaint about Tak is twofold:

1. When you buy one you need to buy the rings, the finder scope, the quick release brackets and lots of adapter for imaging. You stretched yourself for the scope and the addons add another $1200 (no case either).

2. Their threads on their adapters are notorious for binding so badly you may not be able to remove them. I nearly destroyed a reducer because it got locked on so badly. I always coat the threads of new Tak threads with teflon grease (thin wipe) to stop this from happening. They seem to paint a high friction paint on their already very narrow threads.

Greg.

Greg.

[Profiler (Profiler)]

I am very grateful for the feedback. Given that we have a few TSA-102 owners I would be grateful if someone could clarify whether the TSA-102 has a colliminable lens cell?

I know the previous FS-102 did and I came across a reference to the TSA-102 also having a colliminable lens cell on one website but thereafter I can't seem to find anymore information on this particular point on other websites.

[Exfso (Peter)]

As far as I know it does not have a lens cell that can be collimated other than at the factory. In any case even if it did, the air spaced triplets made by Takahashi are not easy collimated without special equipment. I have a TOA130 it does have the collimation screws, but there is no way this little black duck would even consider touching them. Horses for courses I reckon. I have now had this scope a couple of years and it is in excellent collimation. If it does go out, well it is back to Japan, as the local Tak distributer does not have the equipment or the knowledge to collimate their scopes, unlike the American counterpart who do all their own servicing. Interesting enough, the Yank Taks purchased from there have a 5 yr warranty and those purchased from the Aust distributor only have a 3 yr warranty, apparently Takahashi America or Texas Nautical repair as they are called add the extra 2 yrs warranty I believe. I cant imagine the Australian distributor doing that, but I will not go into that.

[Paul Haese]

The answer to that is yes and no. Yes it has a collimating lens cell, but no it should not and generally cannot be collimated by the average punter. The reason being that the collimation screws are deliberately gelled up with resin by Takahashi. That said though these scopes are pretty robust, short of actually dropping one (hey Pete), they do not require collimating. Never felt the need to collimate mine.