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80mm class and 100mm class (reason to keep both?)

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#26 Tyson M

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Posted 27 November 2019 - 09:48 PM

If your end state goal is more NV observing and possibly DSLR AP (you can use a DSLR for EAA too) I would suggest you sell both scopes and buy a AT92. It is in the middle of both, it is more portable, it is better for NV and EAA because it is an f/5.5, and it has a good focused on it as well as accessories for AP/EAA that are affordable. It is here:

https://www.astronom...ractor-ota.html

Remember as a CN member you get a extra discount on equipment bought from Astronomics so that helps too. You just have to mention in the notes field on the order that you are a CN member and give your user name.

If you are going to remain a visual observer then keep the 103. It has 21mm more aperture than the 82. And that 21mm is enough to see a noticeable difference in objects.

I went this route with the AT92.  No EAA yet but since I have it, that option is on the table potentially in the future.  It is a scope that exudes quality, with fantastic optics and extreme portability.

 

I find myself using it lots, or wanting to use it lots. 

It effectively splits the difference between the 80mm class and 100mm class.  The 100mm class without a sliding dew shield always feels a bit long in the tooth.  They can ride on the smallest mounts and phototripods like your vixen103S, but they are physically large scopes I find.  Not necessarily a deal breaker, but it could be if space is tight.

 

With any fast scope, focus is precise but the dual speed focuser does the job well and there is a great snap to focus.  I typically love my long focal length scopes more, but I find myself happy with the AT92 for its ability to do everything in the smallest possibly package.

 

I love Vixen ED doublets as well, so there is no wrong option here.  Only the option that works best for you and your needs. 


Edited by Tyson M, 27 November 2019 - 09:51 PM.


#27 GOLGO13

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Posted 27 November 2019 - 10:15 PM

Thing is GOLGO doesn't sound like a guy slowing down , just seems as the 81 is a tweener (60mm-103 mm ) that doesn't get much attention , Vixen 130 ss , sound familiar GOLGO , I might be mistaken but I thought you had one at one time


That is the thing. Originally I sold my 103s because I had the 81s and the 130ss. Once I sold the 130ss I was like, I need a bigger refractor and picked up the 103s again. With the 130 and 81 I was totally cool with that situation. But the 103 and 81 currently perform the same function on the same mount. Money is probably too tight to keep the 81 at this point.
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#28 aa6ww

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Posted 28 November 2019 - 01:12 AM

There’s allot to be said for the portability of a smaller 80mm refractor. I’ve never heard of an astronomer miss a Lunar X or solar event or just a few hrs. of back yard fun who owned a portable 80mm size refractor.
I hear it all too often with a 100mm size scopes however.

 

Its the mount that makes the system portable, not the scope itself. There’s really no difference in effort mounting an 80 or 100mm refractor on a mount, but the mount can make a big difference to uninspired ho hum astronomers who look for any excuse not to set up. I get this way myself sometimes.

 

People with very lightweight 80mm scopes always find their way to a matching very lightweight very portable mount to compliment the simplicity of the 80mm set up.

 

Easy Peasy always make sense when your tired but still want to catch a few night time objects, especially as the weather gets colder outside.

 

I’d think the 100mm would be the one to off load. There are 115mm to 120mm which are the size of the 100mm and doing the swap would keep the 80 and you’d have a more potent larger scope which would be physically very little difference in size to the 100mm.

 

 

...Ralph


Edited by aa6ww, 28 November 2019 - 01:36 AM.

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#29 213Cobra

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Posted 28 November 2019 - 05:40 AM

After a few decades with a 160mm hyperbolic f/3.3 corrected Newtonian being my primary scope, supplemented by a 100mm Cat, I ventured into refractors after a long, unintended delay in 2018. Because I had a strong affinity to my flat field Newtonian astrograph for visual, I wanted to confirm to myself that fast flat field quads would similarly be the best route for refractors for me. So the first refractor I bought was a Stellarvue f/6, 80/480  LOMO. I knew a quality triplet would be razor sharp, but my intent was to put a Takahashi FSQ-85ED flat field quad astrograph up against it, and choose a winner. I ended up adding a TSFlat2 flattener to the LOMO, and then soon acquired an FSQ-85ED for the smackdown. Plus an f/7.5 80/600 LOMO to boot.

 

There is no useful criticism of a LOMO triplet. I have two of them, and both look essentially perfect to me, with scintillating, high-contrast, ice-cold views. There is also no useful criticism of the Takahashi 85mm quad astrograph. It has similarly high-definition views, but it substitutes more color nuance and organic subtlety for the ultra-etched white-on-black definition of the LOMOs. They are "the same but different." Variations on a theme.

 

Then I wanted to find out what differences between easy and compact, fast 80mm scopes and 100mm+ counterparts would materialize. I established the value of the FSQ quad at 85mm, so I stepped up to the 106mm FSQ-106 EDX. When seeing is exceptional, the 106 reveals discernibly more detail in any target it's pointed at. It's not a revelatory difference, but it's noticeable. When seeing is poor, the 80-85mm alternatives are more useful. Now, you can accomplish this with an aperture mask, but all I can say is, it's not the same as stepping down to a dedicated smaller, high-definition optic. The 106 is more revealing of small details than the ~80s, but it is also bulkier, heavier and a bit less spontaneous.

 

I then went smaller because both seeing at times, and more perfect optics in the form of Takahashi FOA-60Q and FS-60Q, fulfilled their theoretical promise for outperforming intrinsic expectations from their aperture, and proving incisive under specific conditions while also serving spontaneous interests.

 

Now, almost two years later, I could sell my two 80mm LOMOs. I use them least among my refractors, which isn't the same as saying I appreciate them less than I did at the outset. Maybe I will sell them to help pay for the TeleVue NV compound apparatus. Or maybe not. I am not financially required to give them up and they present a slightly different aesthetic than the nuanced, less binary quads. Is keeping them necessary? No. Is it interesting? Yes. The outcome is uncertain. I can only say that I will keep my two FSQs and they will not leave for keeping the LOMO triplets.

 

The subtlety of differences between various similar-size & similar-execution refractors is greater than between similar size-and execution reflectors. The aesthetic differences are beyond the objective diameter differences, and the hardware itself is unusually engaging in a tactile sense. You really have the sense that all the light is going through glass, rather than bouncing off of it. Is there a truly objective reason to keep both a compact 80mm refractor and a manageable 100+ mm refractor? No; or at least that's debatable. Refractors in general give me better views of high-magnification objects than my f/3.3 reflector but is there any real difference in the pleasure of using all of them? No. But depending what I am looking to see, and the sky conditions overhead, sometimes my 60mm f/15 is the right tool, and sometimes my 80mm f7.5, and sometimes my 106mm f/5, and sometimes my 85mm f/5.3. And sometimes my 160mm f/3.3. And sometimes my 60mm f/10. I bought the 80mm LOMOs as a triplet reference to test whether my preference for astrographs would persist in refractors. It did. But the LOMO triplets are convincing and interesting so for experiential reasons I have so far kept them. The 60mm Takahashi quads are again their own thing entirely -- a chance to see virtual perfection without unobtainium prices. Where does a RedCat 51 v2 Petzval fit? Stunning wide-field, flat-field views from a scope small and light enough to take anywhere, no matter what your limitations.

 

This is how people end up with multiple refractors.

 

Phil


Edited by 213Cobra, 29 November 2019 - 02:59 AM.

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#30 WyattDavis

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Posted 28 November 2019 - 07:04 AM

There’s allot to be said for the portability of a smaller 80mm refractor. I’ve never heard of an astronomer miss a Lunar X or solar event or just a few hrs. of back yard fun who owned a portable 80mm size refractor.
I hear it all too often with a 100mm size scopes however.

 

Its the mount that makes the system portable, not the scope itself. There’s really no difference in effort mounting an 80 or 100mm refractor on a mount, but the mount can make a big difference to uninspired ho hum astronomers who look for any excuse not to set up. I get this way myself sometimes.

 

People with very lightweight 80mm scopes always find their way to a matching very lightweight very portable mount to compliment the simplicity of the 80mm set up.

 

Easy Peasy always make sense when your tired but still want to catch a few night time objects, especially as the weather gets colder outside.

 

I’d think the 100mm would be the one to off load. There are 115mm to 120mm which are the size of the 100mm and doing the swap would keep the 80 and you’d have a more potent larger scope which would be physically very little difference in size to the 100mm.

 

 

...Ralph

That makes sense to me. Keep the lightweight 81mm and consider a 5" refractor. If it is going to be heavier anyway, why not get to a clearer next level in light gathering power? As I recall, a certain excellent astronomer down in Texas opined as much when I pulled the trigger on my 102. Maybe he was right about that 115/120/125....  :^))



#31 Illinois

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Posted 28 November 2019 - 07:16 AM

I have 80, 100 and 150 mm refractors. I love my 80mmED and keep it! Now its about 10 years old and perfect for my travel up north for dark sky! 24mm 80deg. eyepiece is great! 25 power and little over 3 degrees of view. Great for faint deep sky objects like Veal Nebula and plenty of DSO from low to around 80 power. I have SW150 refractor and I love it. I don't use 100mm ED and I will plan to sell it or give to my daughter!


Edited by Illinois, 28 November 2019 - 07:17 AM.


#32 earlyriser

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Posted 28 November 2019 - 07:27 AM

Maybe you could put the 81mm away for a few months to see if you miss it before deciding. 


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#33 Jon Isaacs

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Posted 28 November 2019 - 11:14 PM

Maybe you could put the 81mm away for a few months to see if you miss it before deciding. 

:waytogo:

 

For my own telescopes, I just watch my telescope usage from a distance.  

 

That moment when I decide which telescope(s) I will use each night is the most honest, most real summation of all my thoughts, experiences and feelings about my scopes.  If I haven't used a telescope more than once or twice in a year, then that's a good sign it's time to find it a new home.

 

Jon



#34 drd715

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Posted 29 November 2019 - 10:31 AM

I have a situation which I need some help with. I have a 103s and 81s and I'm wondering what the benefit of having both is. The reason this is tough is both scopes are quite similar. Even though the 81s is smaller, it's about the same for me mounting it up on my Vixen Porta Mount (with wooden legs and an extension). Both come to zenith.

I'm having a hard time imagining needing both. Both have near perfect star tests and perform the same.

The only difference is my 103s has a moonlite and the 81s has the original single speed focuser. I have a reducer meant for DLSRs which will only work on the 81s. I don't currently do astrophotography and I am unsure I will ever want to. I did have this up for sale, but realized the focuser pinion needed replaced and I took it down. But now I have that fixed but was unsure if I should put it up again (well, let the dude know who was interested). With my Vixen GPD2 which is upgraded to GOTO with a SynScan I certainly could give DSLR imaging a try. But quite frankly I'm not even sure I could get a real polar alignment done and my DSLRs are older Nikon ones (D40 and 3100) which are probably not great for doing AP. My patience for learning and doing something like that is low. Which is why I enjoy night vision astronomy.

I do night vision astronomy, but these scopes have higher F-ratios and are more used for planets and ultra wide fields (well, wide for my situations). They are really good for 3 degree+ wide fields with my 34mm 68.

Can you think of any reason to keep the 81s? Because of the fixed dew shield and F7.7, it's not exactly portable. I can say with certainty it's extremely good optically though. Just can't think of a reason where it would be needed. It's slightly wider FOV, but not sure that's enough to keep it. Seeing that I have so many other scopes that fit a purpose. The 60mm being my ultra portable setup. The two newts are night vision and the 10 inch is my deep space setup. The 8 SCT for night vision small objects. The 90mm mak is my solar observing setup (the filter does work on the 81s). The 103 is my main refractor for planets, wide field, etc.

Thanks for any suggestions.

It would be a nice auto guider scope for astrophotography.

Sent from my SM-N950U using Tapatalk

#35 Jared

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Posted 29 November 2019 - 11:27 AM

If:
- The scopes are of similar optical quality
- The scopes are of similar mechanical quality
- The scopes are used on the same mount
Then:
- There is no point to owning the 81 mm scope

I would say you have three choices. The first is, of course, to sell the 81 mm scope. The second is to find a smaller mount for the 81 mm that is not sufficient for the 103 mm. The third is to sell the 103 mm for an even larger telescope.

Personally, I’m not in favor of option two since it feels “manufactured” rather than truly useful. I’d also skip option three since that takes you into uncharted territory that should only be explored if you have a true yearning for more aperture. “There be dragons” if you follow this path.

I’d go with option one. It doesn’t sound like you are yearning for a refractor larger than 100 mm, and the 81 mm just isn’t doing you any good.
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#36 Tyson M

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Posted 29 November 2019 - 11:17 PM

If:
- The scopes are of similar optical quality
- The scopes are of similar mechanical quality
- The scopes are used on the same mount
Then:
- There is no point to owning the 81 mm scope

I would say you have three choices. The first is, of course, to sell the 81 mm scope. The second is to find a smaller mount for the 81 mm that is not sufficient for the 103 mm. The third is to sell the 103 mm for an even larger telescope.

Personally, I’m not in favor of option two since it feels “manufactured” rather than truly useful. I’d also skip option three since that takes you into uncharted territory that should only be explored if you have a true yearning for more aperture. “There be dragons” if you follow this path.

I’d go with option one. It doesn’t sound like you are yearning for a refractor larger than 100 mm, and the 81 mm just isn’t doing you any good.

Very concise breakdown. Agreed 100%



#37 AstroKerr

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Posted 01 December 2019 - 10:31 AM

  If the only reason you pulled the 81s offer was the pinion problem and you've fixed it to your satisfaction, then pass it on, along with the flattener and a Nikon or two if ya really don't have a use for them - some budding AP gazer would be most happy.

 

  Was gonna say "I'd keep it" - just because it's a nice Vixen - but if you don't need it - don't keep it. We almost picked up a Vix 105M & Custom 90M 'just because' but those bases are covered, so we passed. Tormentuous, but seems smart. 



#38 GOLGO13

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Posted 01 December 2019 - 10:58 AM

Yes, didn't want to sell it with a bent pinion. It is perfectly fine now. I will probably sell it soon. Still trying to get a hold of a person that was interested.

#39 dscarpa

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Posted 01 December 2019 - 12:45 PM

 Maybe the 80 could serve as a finder. I really like having a 80 Lumicon Super Finder on my C9.25 , it's almost a 2 scope combo. David



#40 GOLGO13

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Posted 08 December 2019 - 12:27 PM

hmm...was getting this ready for sale and put on the DSLR. Now I'm not so sure if I want to sell it. haha.

 

Took this image and it looked pretty nice.

 

vixen81s

 

What would be the advantage of using my 103s or 81s over just a regular zoom lens?

 

Believe this is a .67 reducer. The 81s is 625mm and the 103s is 795mm. 




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