20 replies to this topic

[AstroCub]

Greetings fellow obsessives

 

I am looking to downsize with portability (weight + OTA length) in mind and am considering an SVX140. 

 

My SVX180 gives mind bending Solar System views but is also getting mind bendingly heavy for me to lift these days. It remains to be seen whether or not I sell my 180, but I am extemely attached to her. 

 

Anyway - so if you are an SVX140 owner and have experience of visual planetary observation, would you mind sharing your experience here, please? 

 

My 180 is F7 and the 140 is 6.7, so maybe less suitable than the 180 for planetary but how much does difference does that actually make? (Aperture aside.) Is it the case that, as Mr. Spock said to Alfred Korzybski when he time travelled to the 20th century, that any difference that makes no difference is no difference at all?

 

(Aside from Solar System visual observing, I will also be using the 140 for general DSO imaging and I have a complete suite of SVX imaging and focusing accessories, hence me not considering a larger doublet, plus we would be back to longer focal lengths affecting portability considerations for me.)  

 

My priority in downsizing is portability, hence I have eliminated the F8 SVX152 from my list as, although that scope is half the weight of my 180, it's still nearly as long. 

 

So how do your like your visual views of Saturn, Jupiter and the Moon through your 140? Please share! 

 

 

Thanks & regards

 

Siouxsie  

Edited by AstroCub, 09 April 2025 - 08:48 PM.

[drd715]

Planets are bright so exposure is not really an issue. However diameter  has some effect upon ultimate resolution. Both the 140 and the 180 will resolve to a point better than the average sky seeing conditions, but on super stable days or selecting the best subs from a video run the 180 will do a notably better job.  Also, the local ratio is better on the 180 and may put the details of a planet over more pixels. Increasing the focal ratio with a barlow or focal extender to the F-20 range works ; particularly if you are already using one on the 180. All you need is a different X factor.  If you currently don't use a barlow on the 180, then the extra glass surfaces when using one on the 140 could lesson the ultimate resolution in the final image.  But will it be noticeable in the final image? Probably not unless you are imaging in exceptionally stable conditions and in high altitude dry air.  I feel for you on deciding to use a smaller scope. I use a 152 and am considering a 140 for my more often use in dso imaging. But the galaxies and smaller dso's  (and planets) could definitely use more focal length. Maybe a 9.25 Celestron sct - maybe.  I would try the 140 to see how it goes; you can always resell it if it doesn't pull out the maximum resolution you desire.  These stellarvue 140s hold great value. Contact Vic and see if he has a trade in 140 at a good price. Or ask him directly on the phone what he thinks about going from the 180 to the 140.

[GADify]

Planets are bright so exposure is not really an issue. However diameter  has some effect upon ultimate resolution. Both the 140 and the 180 will resolve to a point better than the average sky seeing conditions, but on super stable days or selecting the best subs from a video run the 180 will do a notably better job.  Also, the local ratio is better on the 180 and may put the details of a planet over more pixels. Increasing the focal ratio with a barlow or focal extender to the F-20 range works ; particularly if you are already using one on the 180. All you need is a different X factor.  If you currently don't use a barlow on the 180, then the extra glass surfaces when using one on the 140 could lesson the ultimate resolution in the final image.  But will it be noticeable in the final image? Probably not unless you are imaging in exceptionally stable conditions and in high altitude dry air.  I feel for you on deciding to use a smaller scope. I use a 152 and am considering a 140 for my more often use in dso imaging. But the galaxies and smaller dso's  (and planets) could definitely use more focal length. Maybe a 9.25 Celestron sct - maybe.  I would try the 140 to see how it goes; you can always resell it if it doesn't pull out the maximum resolution you desire.  These stellarvue 140s hold great value. Contact Vic and see if he has a trade in 140 at a good price. Or ask him directly on the phone what he thinks about going from the 180 to the 140.

 

Can't compare to the 180, but I got my SVX140T via their Certified Preowned program and you could not tell it from new. Vic told me that people were trading up to the 180 from the 140s which is how mine became available. .99 Strehl - it's a monster.  No planet pics yet because I think it's been clear for one night since I got it and I spent that night looking through it.

[AstroCub]

Can't compare to the 180, but I got my SVX140T via their Certified Preowned program and you could not tell it from new. Vic told me that people were trading up to the 180 from the 140s which is how mine became available. .99 Strehl - it's a monster.  No planet pics yet because I think it's been clear for one night since I got it and I spent that night looking through it.

I got my 180 from Stellarvue CPO. I was very lucky to be in right place, right time for it. 

 

I am strictly visual for solar system objects. I am imagining that the 140 will give wonderful views, just a slightly smaller image scale and not quite as bright as the 180. Hopefully there will be other owners coem forward to share their experiences. 

 

Good luck with yours, and I wish you a clear mind and steady skies! 

 

Siouxsie 

[AstroCub]

Planets are bright so exposure is not really an issue. However diameter  has some effect upon ultimate resolution. Both the 140 and the 180 will resolve to a point better than the average sky seeing conditions, but on super stable days or selecting the best subs from a video run the 180 will do a notably better job.  Also, the local ratio is better on the 180 and may put the details of a planet over more pixels. Increasing the focal ratio with a barlow or focal extender to the F-20 range works ; particularly if you are already using one on the 180. All you need is a different X factor.  If you currently don't use a barlow on the 180, then the extra glass surfaces when using one on the 140 could lesson the ultimate resolution in the final image.  But will it be noticeable in the final image? Probably not unless you are imaging in exceptionally stable conditions and in high altitude dry air.  I feel for you on deciding to use a smaller scope. I use a 152 and am considering a 140 for my more often use in dso imaging. But the galaxies and smaller dso's  (and planets) could definitely use more focal length. Maybe a 9.25 Celestron sct - maybe.  I would try the 140 to see how it goes; you can always resell it if it doesn't pull out the maximum resolution you desire.  These stellarvue 140s hold great value. Contact Vic and see if he has a trade in 140 at a good price. Or ask him directly on the phone what he thinks about going from the 180 to the 140.

 

I am more or less 100% visual only on Solar System objects but I appreciate your input.

 

I started my visual astronomy journey on SCTs but once I had observed planets through a refractor - there was no turning back.

 

(Although I am strictly visual on the planets, for anyone wanting to image Solar Sytem objects, a SCT is hard to beat because of the focal length. Better still though, a Maksutov Cassegrain at typically F12 is probably the ultimate Solar Sytem imager and is a real unsung hero IMHO. A 180 Maksutov can be had from Skywatcher, for example, for $1,500 which I think is an absolute steal.) 

 

I had a few conversations with Vic about this general topic which kinda lead me to ask other 140 owners what they thought of their visual views. I got my 180 CPO from Vic, I was very lucky with that. 

 

Best, 

 

Siouxsie 

Edited by AstroCub, 09 April 2025 - 10:49 PM.

[Joe G]

Siouxsie,

 

I remember when you got the AT 125 EDL and were thrilled with the views.  A 140mm scope only gives 25% more light gathering than the 125mm scope.  For bright planets and the moon, that will not make much of a difference.  I understand the weight differences between the SV 185, but just use your first refractor, the AT 125 EDL.

 

You are over- analysing it.

 

If you think the seeing is going to be spectacular, drag out the 185 or your larger aperture scopes.  But the AT 125 does a great job.  Doubt the extra 15mm in aperture will make a difference.

[AstroCub]

Siouxsie,

 

I remember when you got the AT 125 EDL and were thrilled with the views.  A 140mm scope only gives 25% more light gathering than the 125mm scope.  For bright planets and the moon, that will not make much of a difference.  I understand the weight differences between the SV 185, but just use your first refractor, the AT 125 EDL.

 

You are over- analysing it.

 

If you think the seeing is going to be spectacular, drag out the 185 or your larger aperture scopes.  But the AT 125 does a great job.  Doubt the extra 15mm in aperture will make a difference.

♪♫♬ Hey Joe, where you goin' with that doublet in your hand? ♪♫♬

 

Hey there

 

Thanks, I appreciate that perspective.

 

I might be inclined to agree with you more if I wasn't planning to do (DSO) imaging with the 140 as well as visual.

 

Hence wanting a triplet. As well as loving Stellarvue telescopes, I want to keep in that eco system because I have all the imaging accessories including focus motors etc from my 180 that can be used on the 140.

 

 

Best wishes

 

Siouxsie

Edited by AstroCub, 10 April 2025 - 09:37 AM.

[TelescopeGreg]

♪♫♬ Hey Joe, where you goin' with that doublet in your hand? ♪♫♬

 

Hey there

 

Thanks, I appreciate that perspective.

 

I might be inclined to agree with you more if I wasn't planning to do (DSO) imaging with the 140 as well as visual.

 

Hence wanting a triplet. As well as loving Stellarvue telescopes, I want to keep in that eco system because I have all the imaging accessories including focus motors etc from my 180 that can be used on the 140.

 

 

Best wishes

 

Siouxsie

For DSO imaging with the 140 you're probably going to want to add a reducer / flattener to it, if you don't already have one.  I have the SVA130EDT without a reducer, and many targets are a tight fit, if they even fit at all.  Mosaics work, but they take time.
 

[AstroCub]

For DSO imaging with the 140 you're probably going to want to add a reducer / flattener to it, if you don't already have one.  I have the SVA130EDT without a reducer, and many targets are a tight fit, if they even fit at all.  Mosaics work, but they take time.
 

I have a flattener lined up, the one I currently use for my 180. 

 

I'm thinking for any bigger targets (that could be a bit tight for F6.7) I'll use one of the RASAs or the Space Cat.    

[TelescopeGreg]

I have a flattener lined up, the one I currently use for my 180. 

 

I'm thinking for any bigger targets (that could be a bit tight for F6.7) I'll use one of the RASAs or the Space Cat.    

Sounds good.  You might check with SV that the flattener for the 180 is optically good for the 140.  I recall a general comment some years ago that reducer / flatteners are somewhat scope specific.  No idea if the Stellarvue ones are interchangeable.

[AstroCub]

Sounds good.  You might check with SV that the flattener for the 180 is optically good for the 140.  I recall a general comment some years ago that reducer / flatteners are somewhat scope specific.  No idea if the Stellarvue ones are interchangeable.

No, the SFFX-2 is designed to work with apertures from 130-180.

 

https://www.stellarvue.com/sffx2/

 

As mentioned, I am using the flattener from the 180, just needs different spacers / extensions for back focus differences. 

Edited by AstroCub, 10 April 2025 - 03:30 PM.

[Oberon510]

I use the flattener with my SVX130T on imaging duty. For visual on the planets I have been happy with good eyepieces (TV Ethos 21 and 8) but there is no substitute for aperture.

 

Maybe the FOV calculator may offer a little perspective - 

 

https://astronomy.to..._system=jupiter

 

Good luck.

[SilverLitz]

My SFFX-2 that came with my SVX130T works great with my vintage SV152 (TMB-LZOS lens; same FL as new SVX152T), with only ~1mm change in BF distance.  Vic told me how much to increase, and it was spot on.  I really like the huge SFFX-2 and I suspect it could be better than the newer SFFX-3, due to its significantly larger clear aperture.  I suspect the new SFFX-3 would have the same optical formula, but is smaller to work with SV's 3" focusers as well as the 3.5" FT.  This allows SV to have only 1 SKU for FFs instead of 2 SKUs, and Starlight's post-COVID shortage of FT focusers have cause SV to prioritize their 3" focuser instead (my speculation).

[Joe G]

♪♫♬ Hey Joe, where you goin' with that doublet in your hand? ♪♫♬

 

Hey there

 

Thanks, I appreciate that perspective.

 

I might be inclined to agree with you more if I wasn't planning to do (DSO) imaging with the 140 as well as visual.

 

Hence wanting a triplet. As well as loving Stellarvue telescopes, I want to keep in that eco system because I have all the imaging accessories including focus motors etc from my 180 that can be used on the 140.

 

 

Best wishes

 

Siouxsie

Hey Joe, oops, that is me.  I understand you are the Steward of Leda.  Is there not a reducer/flattener for that?

 

Obviously if you give Stella to a good family that would free up a lot of funds for a 130-140mm scope with matching reducer/flattener.

 

Good luck.  Seems like your post hurricane burnout has abated?

[AstroCub]

My SFFX-2 that came with my SVX130T works great with my vintage SV152 (TMB-LZOS lens; same FL as new SVX152T), with only ~1mm change in BF distance.  Vic told me how much to increase, and it was spot on.  I really like the huge SFFX-2 and I suspect it could be better than the newer SFFX-3, due to its significantly larger clear aperture.  I suspect the new SFFX-3 would have the same optical formula, but is smaller to work with SV's 3" focusers as well as the 3.5" FT.  This allows SV to have only 1 SKU for FFs instead of 2 SKUs, and Starlight's post-COVID shortage of FT focusers have cause SV to prioritize their 3" focuser instead (my speculation).

Hey there

 

Thanks for your input and also to say thanks for a recommendation you gave me a while back for the Optec focus motor system. 

 

I subsequently bought that system for my SVX180 on the back of your recommendation and it works beautifully. If I get a 140 I will get it with the FT focuser so that I will be able to use the Optec motor etc on it, 

 

Best

 

Siouxsie  

[AstroCub]

Hey Joe, oops, that is me.  I understand you are the Steward of Leda.  Is there not a reducer/flattener for that?

 

Obviously if you give Stella to a good family that would free up a lot of funds for a 130-140mm scope with matching reducer/flattener.

 

Good luck.  Seems like your post hurricane burnout has abated?

 

♪♫♬ I said Hey Joe,

where you goin' with that doublet in your hand?

I'm goin down to shoot my old favourite M104

You know I caught her with anoher galaxy on a clear night ♪♫♬

 

About Leda - rightly, wrongly, I can't really bear to use her as I don't consider her mine. I have peeked through her a few times on nice evenings but that's really as far as I'm prepared to go.

 

About Stella - I have decided to keep her, she is so special. I will see if I can twist my brother's arm to build an observatory around her, that's what she was made for and where she belongs. 

 

I probably will go ahead with the 140 anway, either Simon (brother) or I am due to speak with Vic about that later.

 

Yes, I have recovered pretty much intact from the hurricane, thanks for asking. Had to move out for 2 months and have only recently come back and trying to get things together. I am aiming / hoping for my first visual astronomy session to be around 3rd week of April New Moon.

 

Best wishes

 

Siouxsie 

Edited by AstroCub, 11 April 2025 - 10:33 AM.

[peleuba]

So how do your like your visual views of Saturn, Jupiter and the Moon through your 140? Please share! 

 

 

I have looked through two SVX140's and both were excellent.  Trust me, if they were not, I'd be the first to say so.  A friend uses an SVX140 for imaging and really likes it.  His images are spectacular. 

 

But its sort of funny - no one seems to actually use the SVX140 visually.  So, absent that, do the next best thing and look for opinions on the planets when using similar scopes in the 140mm aperture class.  Once you get to a certain level of optical quality - and the SVX140 qualifies in this instance - the long pole in the tent for planets becomes aperture.  To this end, the SVX140 will give similar/same views as the TEC140 and there are tons of reports on both the TEC140ED and the TEC140FL.

 

In my mind own mind as well as my friend Alan French, 140mm APO is the Goldilocks of telescopes.  It represents the perfect combination of resolution, correction, and portability.  Having used both the SVX180 Gen1 and the SVX140, I would take the 140 every time.  Its a worthwhile trade IMO.  I am a devout planetary observer.

Edited by peleuba, 11 April 2025 - 10:33 AM.

[AstroCub]

PS

 

Please keep Vic in your thoughts, he has a really nasty dose of Flu that he picked up at NEAF

[t.r.]

If downsizing is your objective I wouldn’t limit myself just SV…over on the “mart” Herb from ATWB has an ad for multiple TEC FL 140’s available next week for delivery…

[Dean J.]

Yes, I think the TEC 140 would be an excellent choice for those looking in the 140mm range.

 

As Paul mentioned, whatever brand you get, the 140 size is a great combination of portability and power.  My TEC 140FL is reasonably lightweight but does great as an imaging scope as well as a visual scope.

Edited by Dean J., 11 April 2025 - 12:35 PM.

[AstroCub]

Just got my order in for a new SVX140

 

So glad I didn't wait - this tariff war has already caused carnage with supply and supply chains. 

 

My advice - FWIW - to anyone considering a telescope with glass sourced from outside the USA - get your order in NOW. 

 

Siouxsie