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Vixen A81 M vs ?

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#1 jimbooregon

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Posted 06 August 2022 - 09:11 AM

Hi all,

I'm in the research phase of getting a refractor and could use some feedback from experienced folks. This will be my first refractor and the main use will be double stars. No photography. I'm looking at achromats as the bang for buck factor is kinder to my limited funds. Portability is a major concern as well due to my 74 yo back (no dobs.)

After reading every online review that I could find I was leaning towards a Sky Master Evo Star in 90mm or 102mm but the the Vixen A81M and A80mf caught my eye.

Having read so many reviews on different scopes  that said replace the diagonal,finder etc etc is the quality of the A81M such that it's good to go as is, therefore almost as cheap as a lesser quality outfitted scope when the dust settles?

So if I am limited to one scope, with optical quality, finance and portability as main concerns is the A81M the way to go?

Thanks in advance for all the advice.

 

James

Ayr Scotland


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#2 Mike W

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Posted 06 August 2022 - 09:27 AM

Get the Vixen A81M! I believe its like the older Celestron first scope
80 which had good optics (Japan). Combine that scope with some good plossls
and it'll be great on double stars!

Edited by Mike W, 06 August 2022 - 09:39 AM.

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#3 Space_Race_T.J.

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Posted 06 August 2022 - 10:00 AM

This scope gets great reviews and doesn’t break the bank. Weighs 10 lbs. 

TS-Optics 102 mm f/11 ED Refractor with 2.5" RAP Focuser.    657.98 EUR

 

 

The F7 version is the shorter more portable option. Weighs 8.7 lbs

TS-Optics ED 102 mm f/7 Refractor Telescope with 2.5" R&P focuser.    628.57 EUR

 

Clear skies,

 

T.J.


Edited by Space_Race_T.J., 06 August 2022 - 10:14 AM.


#4 db2005

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Posted 06 August 2022 - 10:07 AM

I own the A80M (Japan-made) and use it on occasion. It is an excellent achromat. Light weight, functional mechanics and has killer optics, and performs to the theoretical limit for an 80 mm achromat. It rides pretty well on a Vixen Porta II mount, especially if you upgrade the standard tripod legs. I also used to own the A80mf (China-made) at around half the price of the japan-made version and found it to have very good optics too, but the mechanics of the A80M are better in every way.

 

The only downside of the A80M was the bundled flip-mirror diagonal which was of so-so quality.

 

The next step up in quality from the A81M would the SD81S but it is roughly twice the price and it seems to me the A81M is priced right. How will you mount your scope?


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#5 dnrmilspec

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Posted 06 August 2022 - 10:16 AM

For a couple of hundred dollars you can get an excellent 102mm from Celestron or Skywatcher (used).  I have a couple of these and they are much better than they get credit for.  They would require a bit stouter mount than the Vixen though.  The added aperture would be significant.

 

Looking at ES's site I am seeing this as $749.00 for the OTA?  That is a huge hit for an 80mm Achromat.  Can that be right?  Japanese lens or not it is still an achromat and though I really like achromats for their value I could not spend that for one.  For just over half of that you can get an AT 80 ED scope.  You can get the Takahashi 80 (F10) achromat with mount for over $100.00 less.  You can get the Celestron 102XLT and mount for less and the 5" for only $50.00 more.

 

So if the price I am seeing is correct, and you are going to buy new, I would offer that although Vixen can make a good achromat I am sure, there are much better options out there. 


Edited by dnrmilspec, 06 August 2022 - 10:20 AM.

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#6 jimbooregon

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Posted 06 August 2022 - 10:20 AM

Mounting is another dithering point. I like the idea of tracking at high mags, but the lighter more portable alt az....???? Argh my brain hurts confused1.gif



#7 jimbooregon

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Posted 06 August 2022 - 12:36 PM

Here in the UK, the Vixen is about $578. I can't find a Tak  achromat online here. As far as 80mm app or semi apo they run about $700++. So it sounds like you have more options in the US.

Cheers



#8 betacygni

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Posted 06 August 2022 - 01:28 PM

What max budget are you looking at? While I like achromats for some purposes, and own 2, I wouldn’t pick one for primarily double star use. The Vixen is also exceedingly expensive for an achromat. For similar or less you could get a very nice ED doublets :

Edit: Noticed you’re in UK, changed recommendations:

High end: https://www.firstlig...rd-focuser.html

Value: https://www.altairas...cuser-469-p.asp

Edited by betacygni, 06 August 2022 - 01:40 PM.

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#9 db2005

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Posted 06 August 2022 - 02:49 PM

Since portability is one of your main concerns, have you considered how much weight you will be able/willing to carry? And do you want to be able to carry everything in one trip or would it be acceptable with a two/three trip setup? Also, since double-star observation is will benefit from high magnification, you will need a sturdy mount.

 

You will need to consider what your budget is for the full setup. Then, if you start by choosing a tripod and mount you can work your way backwards to a decide on a suitable telescope that will ride comfortably on that mount. My first "serious" combo was a Vixen Porta mount with an Orion ED80 which I used for many years, and I found them to be an excellent match for low to medium magnification observation. But if you want a very portable setup an 80 mm refractor is about the largest setup I would consider to be very grab-and-go friendly. A 100 mm will be able to show you more but it will also require a beefier mount and be less portable.


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#10 desertlens

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Posted 06 August 2022 - 03:26 PM

The A81M I have is very good optically. The focuser is simple but smooth and it holds weight reasonably well. That said, I think it's expensive as achromats go. I managed to con the vendor into selling me the OTA without the flip mirror, which I didn't really trust in terms of alignment. The backspacing of the scope is designed for the flip mirror which has a path length that is closer to a 1.25" diagonal. A 2" diagonal may or may not have enough in-travel. At any rate, it will be close. I typically use a smaller diagonal with this scope. I've never been crazy about Vixen rings and dovetails so I replaced those as well, just a personal preference. The only real negative; on my sample, the stock visual back was horrible and was immediately replaced with the Baader click-lock shown. In the end, I went with this shorter visual back to gain some in-travel.

https://agenaastro.c...ck-2458196.html

 

VixA81Mx.jpg


Edited by desertlens, 06 August 2022 - 03:32 PM.

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#11 Sol Robbins

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Posted 06 August 2022 - 08:18 PM

Here' one that is bundled with an alt/az mount, tripod, star diagonal and a couple simple design ok eyepieces. It's an 80mm achromat made in Japan scope you might want to consider, and it reads in stock.You can search for reviews here in this forum.

 

https://landseaskyco...escope-w-tripod

 

Best,


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#12 godelescher

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Posted 06 August 2022 - 09:36 PM

The Japanese-made Takahashi starbase 80 is available from first light optics and comes with a mount. Reviews have been very good on that scope.

Scopetech also makes long focal length achromats that have been very well received.

I have owned and loved many different Vixen scopes, but I believe that some of the current generation of Vixens are no longer actually made by Vixen. Vixen optical has been making superb optics for generations, but if they're no longer manufacturing their own lenses and OTAs, then it seems like you're just paying a premium for the decal.

My vote would be for the starbase 80, which isn't made by Takahashi, but is made to Takahashi specs by...Hino optical, I think. It's a serious achromat that will excel at doubles


Edited by godelescher, 07 August 2022 - 09:33 AM.


#13 barbie

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Posted 06 August 2022 - 09:46 PM

As much as I love longer focus achromats, I've found that my 80mm f7 ED apochromat does better on the moon, planets and double stars and can be mounted more easily on a lightweight altaz mount/tripod. I still have a soft spot in my heart for long focus achromats of F10 & longer but have conceeded to an aging physical condition and have gone with an 80mm f7ED APO because of it's shorter physical length and lighter and easier to mount tube.


Edited by barbie, 07 August 2022 - 10:43 AM.

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#14 gnowellsct

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Posted 07 August 2022 - 12:28 AM

Vixen A81M

Vixen SD81s

Vixen ED80sf

Vixen A80mf

 

I would like to know what all these are all about.  It seemed that not too long the 81mm meant "made in Japan" and ED apo (so,  f/7.7). The 80mm meant a longer focal ratio and made in China.

 

Now I don't know what any of it means.  Judging from B&H it looks like the A81M is made in Japan but a classic crown flint f/11 which given the aperture yields Sedwick criterion color corretion but falls just short of Conrady.

 

At B&H the ad copy does not say made in Japan for the SD81s but I would bet that it is.

 

The ad copy does not give provenance for the 80mm versions.

 

Maybe someone can straighten me out? I find it confusing.

 

Greg N



#15 db2005

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Posted 07 August 2022 - 02:49 AM

Vixen scopes are still made in Japan, but they also label some Chinese scopes as Vixen.

 

Scope models with an "f" suffix are made in China (such as A80mf) while scopes without the "f" are made in Japan (such as A80M, A81M, SD81S, A105M, SD103S, SD115S).


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#16 db2005

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Posted 07 August 2022 - 03:07 AM

With regards to the A81M vs the A80M vs A80mf models:

 

Afaik the A81M is essentially the latest version of the Japan-made A80M, with a carry handle instead of the carrying strap bundled with the A80M. Also it's 81 mm nominal aperture vs the 80 mm for the A80M.

 

Differences between A80M vs A80mf (I've owned both simultaneously, so I believe I'm qualified to compare them):

  • A80M is made in Japan - A80mf is made in China (by Synta)
  • A80M has a metal lens cell - A80mf has a plastic lens cell
  • A80M paint job is excellent - A80mf paint job is good.
  • Both have rack-and-pinion focusers, but he A80M's is arguably better made. The A80mf contains the dreaded sticky Synta-grease.
  • A80M has a 2" visual back which supports mounting one extra finder if you add other optional finder shoe - A80mf has a standard 1.25" visual back with provisions for just one finder scope
  • A80M is bundled with the thin, light weight white Vixen tube rings and prism rail - A80mf has the typical dark Synta tube rings and slotted prism rail.
  • A80M is bundled with a red dot finder - A80mf has a small finder scope.
  • A80M is bundled with a 1.25" flip mirror which fits the 2" back - the A80mf has a 1.25 diagonal (mine was a 1.25 erecting prism which wasn't great)
  • The A80M is roughly twice the price of the A80mf.

As already stated above, it's an expensive scope for an achromat. But it's worth keeping in mind that this isn't a typical run-of-the-mill achromat. The optics are great. Mechanics and build quality are a healthy step or two ahead of the cheap achromats by the competition. It is light-weight for its size.


Edited by db2005, 07 August 2022 - 11:38 PM.

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#17 db2005

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Posted 07 August 2022 - 03:20 AM

Vixen A81M

Vixen SD81s

Vixen ED80sf

Vixen A80mf

 

I would like to know what all these are all about.  It seemed that not too long the 81mm meant "made in Japan" and ED apo (so,  f/7.7). The 80mm meant a longer focal ratio and made in China.

 

Now I don't know what any of it means.  Judging from B&H it looks like the A81M is made in Japan but a classic crown flint f/11 which given the aperture yields Sedwick criterion color corretion but falls just short of Conrady.

 

At B&H the ad copy does not say made in Japan for the SD81s but I would bet that it is.

 

The ad copy does not give provenance for the 80mm versions.

 

Maybe someone can straighten me out? I find it confusing.

 

Greg N

 

A81M (and A80M): Japan made ~f/11 achromats.

 

A80mf: China-made achromats f/11 achromat (see more details in my previous posts).

 

SD81S: Japan-made f/7.7 ED scope. It used to be called ED81S, but after making some (nominal?) changes they changed the name to SD...

 

ED80SF: Vixen-rebadged version of the classic Orion/Synta/Skywatcher ED80 f/7.5. Don't be fooled by the seemingly similar specs to the SD81S. The SD81S is a completely different scope. Better optics, better color correction, different (and better) mechanics. Also the SD81S is more compact and lighter because it does not use an oversize OTA tube like the ED80 does. Possibly as a cost cutting move on the ED80 they used the same tube as the one used for the ED100.

 

SD103S & SD115S: Japan-made Vixen ED scopes operating at/7.7 focal ratios. Larger siblings of the SD81S.

 

The optical quality and color correction of the SD81S is IME very close to Takahashi level, and I actually prefer Vixen's mechanics to the current mechanics of the smaller Taks, but YMMV.


Edited by db2005, 07 August 2022 - 12:16 PM.

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#18 Hesiod

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Posted 07 August 2022 - 03:29 AM

A mid focus good quality achromat is for sure a fine and pleasant telescope to have, to use, to look it at and to look it through.

Personally have a 100/1000 TAL RS and am very glad I purchased it; however my personal opinion is that the nice Vixen Japanese achromats (and other good quality achros), while sweet telescope in themselves, are not the most effective purchase if are on budget.

In my experience the best bang for the buck actually comes from the 130/650 Newtonian reflectors (by the way, Vixen sell a nice bundle with their Porta mount and this is IMHO an excellent match): these, despite a rather low retail price, have surprisingly good optics and can stand against a 4" refractor.

Speaking of which, the 100mm f/7 doublets made in China and sold under several labels are probably the best bang for buck among refractors: size and weight wise are very close to the A81m (indeed the achromat is longer, and just a tad lighter: both instruments are between 3.5 and 4 kg), but those extra 20mm makes truly a difference.

I do not know the exact pricings in the USA, but at EU pricings the 100 f/7 can be purchased around 750€, which is roughly 150€ more than the A81m and 150€ less than the A105m.

If your budget could be stretched so far, since it would be your only telescope in my opinion it would be worth the effort


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#19 DeanD

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Posted 07 August 2022 - 05:57 AM

How about a spanner in the works? SkyWatcher Evostar 120mm: https://www.altairas...mbly-533-p.asp 

- at £269 it is only £25 more than the Vixen A80Mf but at f8.3 it should have respectable colour control, will split tighter doubles than the 80Mf (or the A 81M) and give way brighter views and enable you to see a much bigger range of DSO's than any 80mm scope...

It looks like the weight of the OTA is around 5.5kg


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#20 Hesiod

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Posted 07 August 2022 - 06:45 AM

Beware that even if the optical tubes are reasonably light up to good aperture, the required mount's weight increases very quickly.

A 120/1000 needs a rather substantial mount like a eq5 or t-sky (these are roughly 10kg heavy), while a 80mm can be used with a much lighter Porta (5kg) or eq3 (ca 7kg) or even a sturdy phototripod (lighter but much more expensive): if can not afford to leave the mount out all the time you have to pay attention to its weight as much as to that of the optical tube


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#21 25585

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Posted 07 August 2022 - 08:00 AM

First Light Optics is selling a Scopetech Starbase 80mm Japanese achro for £549.


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#22 Echolight

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Posted 07 August 2022 - 09:58 AM

If I was bound and determined to limit myself to an 80mm refractor on a budget for doubles, then I would have already ordered Altair Starwave ASCENT 80ED F7 Refractor Telescope with Geared Focuser for £399 that betacygni linked in post #8.

 

Of course if you are dead set on a long scope, and one that is a complete package (aside from mount), then the Skywatcher Evostar 100 f9 would be a better visual tool for double stars specifically than any 80mm scope..
And you won't have to replace the diagonal or the finder. Although the focuser might need a little tuning if you decide to expand it's use with heavy long focal length 2 inch eyepieces. But it'll be fine with the smaller eyepieces generally used for double stars.

It will require a more substantial mount than the little f7 80 though. And be considerably less "grab and go".


Edited by Echolight, 07 August 2022 - 10:11 AM.

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#23 gnowellsct

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Posted 07 August 2022 - 11:16 AM

Thank you for the clarifications about the differences in the different vixen models. I get what vixen is doing. They figure if they have to compete against Chinese exports they might as well compete against their own Chinese exports.

But it does make for confusing marketing. And they are in the difficult situation of saying to someone who asks why some of their 80 mm are less than half the cost of some of their other 80 mm options, they're in an awkward situation and seem to be handling it by saying as little as possible. Because they can't say well you should buy our Japan output at twice the price because our China output. That would be indelicate and for some people the $400 scope is their pride and joy and they don't want to feel bad about it.
And vixen will say hold on our China output isn't really that bad it's just at about the same level as all the other China output. Maybe even a little better. But if you want a terrific scope which is potentially legendary then you should get our Japan model.

If I were going to buy a made in China scope I probably would buy a vixen. I think they are better at coaxing consistent quality control out of the mainland.

The statement that some of the China models have plastic lens cells is a real eye opener. How many such lens cells are out there in the low price ranges. This is the first I've heard about it.

Edited by gnowellsct, 07 August 2022 - 11:19 AM.

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#24 db2005

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Posted 07 August 2022 - 12:24 PM

The statement that some of the China models have plastic lens cells is a real eye opener. How many such lens cells are out there in the low price ranges. This is the first I've heard about it.

I've read one report of cracks developing around the screw holes where the lens cell attaches to the tube of the Vixen A80mf, but I haven't experienced that myself. The two samples that have been through my hands were fine (also optically good), but I wonder how these plastic lens cells hold up over time. Still, at the relatively modest asking price it wouldn't seem reasonable to expect heirloom build. Most importantly the lens elements are still glass grin.gif.

 

The lens cell on the A80M and the SD81S are threaded on, which is arguably better but also requires much finer machining tolerances.


Edited by db2005, 07 August 2022 - 11:39 PM.


#25 jimbooregon

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Posted 07 August 2022 - 01:25 PM

Hey Linda fan.  Thanks for First Light Optics mention! I saw that besides the Star Base 80 they have a 80mm f/15 @ 434 GBP that looks tempting too. Steve Ringwood did a nice write up in Astronomy Now January 2022 . I'm going to seriously look into it.

Cheers


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