Which Takahashi

[Hemi]

G’Day members,

Have been cogitating about a small tak frac for a while. Lots of options and reviews. Head is spinning.

Wants: small portable travel frac, used for 70%visual, 30%EAA.

Can I request your learned advice and experiences?

Currently looking at the 60 FSQ. Don’t have a budget in mind.

Hemi

[ariefm71]

doesn't have to be a tak... for portability i would grab that TV76 or TV85 in the classifieds if i were you

[Rainmaker]

The FS60Q is very nice and can quickly become an FS60CB, even more portable.... beren's TVs are great options ( though I don't have much experience with them).

I have the little FOA-Q which is very nice but pricey for the aperture...
I like viewing doubles in it, they look like a pair of headlights...

[ab1963]

I can vouch for the TV76 as i have had a look through that actual scope myself and it is very very nice plus it's built like a tank, Would get it myself but the wife would do her nut......

[jamespierce]

I've had the chance to own and try most of the smaller taks... don't worry too much about the exact edition of the size variation, there are really no lemons - older taks can often be had for very reasonable prices considering.



Any of the 60s are great, but a little small for visual I think. By the time you have a mount good enough for astrophotography you might as well have a bit more scope too I think.



The 76s are better, but much longer, for only a little more aperture.


A Sky 90 is an amazing portable scope if you can find one.


One of the 100s is probably the best visual scope, and with the right reducer or flattener great for photo use also but they are getting a bit big for easy portable. Still for photo work you always need a solid mount or it's just a frustrating waste of time.


If I could only own one small tak for portable visual and photo use it would be a Sky 90.

[gregbradley]

The nicest Tak I have used for visual was an FS152 fluorite doublet. Stunning.

Greg.

[jamespierce]

Agreed Greg, we had an FS128 - best views, but so large and heavy.

[gregbradley]

Great for visual, kind of poor for imaging though, too much false colour.
I thought the FS152 was relatively light. I had a TEC180 that was much heavier.

Greg.

[jamespierce]

All relative... We moved to a TSA120 for half the weight, and about 2/3 the length. Compared to the big imaging TOA scopes etc the FS series always was light. Very fast to cool also.

[gregbradley]

A TSA sounds like a nice scope. I guess Tak doesn't do a TSA150 so they don't weaken TOA150 sales.

Greg.

[Hemi]

Thanks everyone,

Head still spinning!
80 was really the biggest I was thinking of going. 100mm+ are just too big for me traveling. I have a ES102 CF, which is just too big for travel, nice visual scope though.

The 60FSQ was where I was at, and the sky 90’s are hard to find. I did ask about Taks as that’s what my head wants! but the other recommendations are appreciated, to that end thoughts on a Borg? They have some very interesting combinations.

H

[SkyWatch]

I bought a TV76 a few years back from here. I renovated the laundry, and that was my "payment". Just a thought... ;)

It is an excellent scope and perfect as a travel scope, but I suspect the Taks have slightly better optics. I have seen people suggesting the TV is "diffraction limited", but around 1/5-1/6 wave; and that would fit with my observations. My TSA 102 on the other hand gives a just about perfect star test, and is probably better than 1/8 wave. I had a play with a Sky90 the other day, and it too gave a slightly better star test than the TV76.

Hemi: have you thought about the FC-76DCU: which is the 76mm objective on the FS-60CB rear unit (see Claude's site)? It is $400 dearer than the FS-60Q that you mentioned initially, but gives a 60% brighter image, and is still cheaper than the TV76 which is advertised on this site. It has a fixed dewshield, but like my TSA it can be unscrewed easily to make it more compact for travelling. Of course, if you want to fork out another $400 you can get the retractable dewshield...

Good luck and have fun choosing.

- Dean

[Rainmaker]

This has been my travel scope, FC76DC. I remove the dew shield and visual back and fit caps over the objective and draw tube, my little tripod and manual mount fit alongside it.

[ausastronomer]

Just a word on the Tak Sky 90. Don't own one, spent a bit of time with one.

It does offer an excellent portable package as a travel scope and probably maximises 90mm of aperture into the smallest most transportable easily mountable package you will find.

It's a 90mm F5.6 Flourite Doublet which is exceptionally fast for the design and borders on whether it qualifies as a true apochromat. Most apochromatic flourite doublets are significantly slower. For instance the TV 85 is F7.5 and has less false colour than the Sky 90, but is a significantly longer package with sligthtly less aperture. In a small aperture wide field refractor that you intend to mainly use for low medium power wider field views the Sky 90 is excellent and probably as good a choice as you could make. If you want a small aperture portable scope that you can also use for planetary and lunar work, whilst the Sky 90 will do the job and pretty well, there are better choices around this aperture for that purpose. For instance while the TV 85 is longer, I think it better suited to lunar / planetary and double stars, than the Sky 90. Similarly, just about any decent triplet around this aperture will give slightly better colour correction and high power views than a doublet, but it will also be heavier and generally more expensive. You need to determine what are the most important criteria in your decision process.

Cheers
John B

[Wilso]

Matt’s scope looks pretty good for travel.
It basically come down to what you observe the most and pick your scope to suit that. I’ve the FSQ85, fantastic little scope and portable but at f5.3 not really suited to planets etc. Yes you can use the Tak extender to make it f8 or higher powered eyepieces but the brightness will be compromised compared to a native f8 scope with the same aperture.
The Borg scopes are pretty hard to beat for travel as they break right down , use Cannon glass, plenty of options but expensive.
Good luck with your decision :thumbsup:

[N1]

Re the Sky90, I hear the Borg 90FL takes a similar approach but is better executed. (http://scopeviews.co.uk/Borg90FL.htm)

I have been very happy with the FS-60/FC76DCU package for years now (95% visual). I'd imagine the Q extension would be an upgrade to the bare FS-60, but with the FC76 objective unit I've never felt the need. I could always stop down the 76 back to 60mm to make it an f/9 fluorite doublet if somehow the 76's image quality wasn't good enough at full aperture. That has never happened so far. The scope still gets used in FS60 mode often because the entire setup is ready to observe in under a minute. It's still my most-used telescope despite ready access to a range of instruments up to 18". Recomendation to OP is therefore the FC76 DCU (with the split tube) or, for a bit more reach, the Borg 90FL.

[ausastronomer]

The Borg 90FL looks really nice. It certainly looks beautifully finished.

I've never used a Borg Scope, but a guy I used to correspond with in Canada (now deceased unfortunately), who was a pretty good and conservative judge, rated them very highly, in terms of optics, quality of fit and finish and ergonomically in their adaptability and light weight.

As Roger Vine noted in his review the Borg 90FL has the same specs as the Sky 90 but addresses the shortcomings of the Sky 90. Namely its marginal performance at higher powers for lunar and planetary and also the collimateable cell issue, although I never saw that as a concern with the Sky 90, probably because the owner of the one I used had it properly collimated.

My only concern with the Borg 90FL is the helical focuser. I am not a fan of them on a Newtonian scope when you're looking through the side of the tube. I would really need to try the Borg out to see if my same dislike of helical focusers applied to refractors. That's just a personal thing and I am sure lots of people have no issues with a helical focuser on any telescope.

Cheers
John B

[gts055]

The Sky 90 I have, is a wonderful performer for its aperture. Very light, compact and when mounted on the Takahashi SpaceBoy mount, readily carried outside through doorways. Excellent for me in viewing widefield or higher power for planets and moon when I am too lazy to set up a larger telescope. Mark

[gregbradley]

I checked out the Borg fluorite(approximately 100mm) briefly when considering a small refractor. The images I saw using this scope were unimpressive with some aberrations.

So I took it off the list.

Judge it for yourself though. Probably fine for narrowband.

Check Astrobin and search for that scope and you'll get sample images.

Greg.

[N1]

Hi Greg, was that the 107FL? That one does appear to be marginal, as its numbers would suggest.

@John, the 90FL can be bought with a non-helical focusser if that's what's needed. I have an old Telementor 1 with a helical, and it works great. Accepted, not everyone likes them.

I tried a Sky90 once, side-by-side with the FC76 DC. the 90 is quite a bit heftier than the 76, and while it did go a bit deeper on detail and brightness, the difference wasn't huge. The 76's image of planets and the moon OTOH seemed a little crisper. That difference wasn't big either though. On balance, I enjoyed using the 90 but it hasn't replaced my 76. My 8" dob which was also present showed me that it really doesn't matter all that much whether the small frac is 60, 80 or 90mm, it's still a small frac. I'd say recognise the strengths and weaknesses of the small aperture and get the one with the best ratio of image quality and portability.

[FrancoRodriguez]

I was wondering what your thoughts on the TEC180 were for imaging. I'm contemplating a large frac for an obsy that I'm planning. i already have a great mount so weight isn't a problem. What are your thoughts on TEC 160 or 180 versus TOA150 for imaging?

[gregbradley]

I had a TEC180 for several years. Its about the largest refractor that you could handle personally without help. I had it on a Tak NJP mount mostly which handled it so long as it was well balanced.
With the flattener it gave round stars to the corners. Yuri does not make a reducer for it but AP has now made versions of its superb TCC reducer to fit TEC scopes.

https://pbase.com/gregbradley/image/109538466/large

Overall a good scope. Looking at one german testing site though it seems its not that well corrected in the red. Yuri optimises his scopes for green (visual).

TEC160 I think would not be much different imaging-wise than the 180 as once you hit 150 most scopes are going to be able to do widefield and brighter galaxies.

TOA150 is a superb scope and punches above its aperture with near perfect APO optics. I do see a lot of them for sale though. They are very front heavy and heavy overall. Best to ask Marcus Davies for his opinion as he has used one for several years. His images often surprised me, showing detail other larger scopes did not.

So I would lean towards the TOA150 myself and you probably could pick one up cheaper than the TEC160.

Another one that is not known well but may be excellent is the CFF160.

I am very happy with my CFF105 F6 refractor. Its somewhat of a replacement for an AP scope as they are hard to get and Roland can only make so many.
Greg
Greg.