12 replies to this topic

[Wandering]

Hi All,

 

I was hoping to get everyone's opinion and help with an upcoming purchase I am looking to make. I have always been a fan of Stellarvue's Telescopes and have been a happy owner of their SVX80 Refractors. Lately, I have been in the market to retire my 80mm scope in favor of a larger refractor. The conundrum I am facing is which aperture size I should move to. I have narrowed the choices to either a SVX130 or SVX152. There is definitely a sizable price difference between the two. This new scope will be permanently housed in the Observatory in the yard and will be a dedicated imaging scope. I do not plan to do any full frame imaging with it and will likely use a camera that has a APS-C sized sensor. I am currently using a ZWO 1600mm camera on the imaging train.

 

Is there much in the way of difference in image quality between these two scopes? Ideally, this scope will probably last me for years and years so I am happy to invest the extra money into it if I have to go the SVX152 route.

 

Any advice would be greatly appreciated! Many thanks!

[bobzeq25]

You have the experience. You have the observatory. I assume you have the money.

The 152, hands down. It's a "forever" scope.

It deserves a new camera, rather than the ancient 1600. At a minimum, the ZWO 2600MM. I guarantee you'll love it. More sensitive. Less Noise. Easier to calibrate the lights.

If you can't afford both in the next year, the 130 and the 2600.

[rgsalinger]

Get the 152 would be my advice. I've found that my similar AP155 (using an ASI2400MC and a flattener) gives me an excellent FOV as well as an image scale of around 1 arc second. That means that I get excellent details on all targets and the FOV from the full frame camera allows me to shoot larger stuff. That system is what I would use all the time if I had to choose just one scope. 

[scadvice]

The 152 as all have suggested above if you can afford it. I have the 130 and love it. However, if my planned observatory could have been bigger and I had the bucks I would have wanted the larger scope also. 

It is a whole new world with these larger scopes in sharpness and detail along with a ASI 2600. Here is my 130 scope and the six by eight observatory when I did my first fit check.  Looks tight but it's designed to be remotely used for imaging from my office not visually. 

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[dariv]

Just out of curiosity, why not consider the SVX140T?

[Mike Sandy]

Bigger always seems to be the recommendation - I get it: Go Big or Go Home.  I think if you are building a dedicated imaging rig, I would be less concerned about the aperture and put more weight on the FOV comparison (especially with a APS-C sensor size).  I added a FOV comparison below.  Either scope has some advantages and some limitations depending on the objects you like to image.  The cost is $3.5K higher with the 152, but there or other factors to consider.  The 152 is nearly 50% longer and 50% heavier than the 130.  I'm getting older and while I used to handle an FRC300 by myself - I struggle with much lighter systems these days.  There is a case for the smaller option, it is the way I decide to go - and I have no regrets.  I kept my SVX80T and piggybacked it on the SVX130 so I can image at 910mm or 480mm.  You could also spilt the difference and pick the SVX140.....there's another option.  The good news is you won't go wrong no matter which you choose.  

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[SilverLitz]

I would not necessarily "retire" the 80mm, as either 130 or 152 are nice compliments to the 80.  Use the 80 for large targets and the longer OTA for smaller targets.

 

The size difference between the 152 and 130 is much larger than you probably imagine.  I have the SVX130T and later got a ~20 year old SV152 (1216mm FL, TMB-LZOS lens cell), and I was shocked at how much larger the SV152 was.  The vintage SV152 will be ~ the same length as a new SVX152T, but it is ~9# heavier (both the heavy LZOS cell and older lathed tube).  Taking the SVX130T in/out is easy, but I only take the SV152 off my mount if the incoming weather looks particularly bad (hail or risk of tornado), as it has some meaningful risk mounting/dismounting and not banging the door frame (it is very long and front heavy).  The SV152 requires my wife manning the door, so I can go straight in/out.

 

The 152 will need a much larger mount than the 130.  The 130 will do fine on a G11 class mount, but 152 is best with an AP1100 class mount.

 

As far as imaging is concerned, both will give you great results, but there is a noticeable FL difference (920mm vs. 1200mm), and both should handle full-frame with their FF, and APS-C will be good with the FR (full-frame capability is unknown with the newly released FR; the old FR was fine at APS-C but not that good full-frame).   If you only have 1 OTA, the SVX130T's shorter FL has more target flexibility, but with the SVX152T you should keep your 80mm for the larger nebulas (probably should keep either way).

 

Since getting my SV152, my SVX130T has not be used that much.  However, I have two mounts going at all times, keeping the SV152 (w/ QHY268M) on my AP1100 for the small targets, and one of my other shorter OTAs on my Mach2 for larger targets.  As much as I love my SV152, I would not want to have it as my only OTA, as there are always good medium/large targets to image.

[Wandering]

Everyone!

Many many thanks for all of your great feedback and insight!

 

bobzeq25
I am definitely looking into the 2600mm, however I will likely have to buy a new set of filters for it as my current camera uses 1.25” filters. Since I live in Bortle 6 skies, I will likely need a 3nm SHO set for it. ….and those types of filters can be a bit pricey. The 152 will definitely be the forever scope.

 

Rgsalinger
I have always heard a lot of good things about the 152 and the details on the photos it has produced is simply amazing.

 

Scadvice
That is an awesome ROR Observatory! I love the build and craftsmanship on it! The new scope will be housed in an Explora Dome in the backyard.

 

Dariv
The 140 is certainly in contention as a middle ground choice!

 

Mike Sandy
You make a very good point on this! Under ideal circumstances, I would want a Wide Field, Medium Field and Narrow Field setup. I ran the measurements for the 152mm OTA length and it should fit in the Observatory with just a smidge of wiggle room to spare. If I were to make any purchase, I would have to run measurements of the whole imaging train and auxiliary equipment to be absolutely sure on everything before I sink a small fortune into another scope.

 

SilverLitz
That’s not a bad idea to repurpose the 80mm. I may look into putting a reducer on it to bring it down to a f/4.5. If I did that, I may not need to install my RedCat51 as the wide field scope. …or I could install  both as the mount (Paramount MEII) should have the capacity to handle quite a few scopes.

 

Overall the ultimate objective is to have a setup that contains a Wide Field Scope (RedCat51), Medium Field Scope (Stellarvue 130, 140 or 152) and a Narrow Field Scope (Celestron 1400HD). The only drawback is that I would have to move the camera depending on the target I would wish to target. I believe that my mount should be able to handle that kind of setup without getting fatigued so to speak.

 

I certainly have some homework to do! I believe that the SVX152 will be the best option as it will probably be a “Forever” scope….or until a Tornado hits the house. The weather in my area is always a crap shoot at any time of year!

 

Many thanks again everyone for your help, insight, feedback, suggestions and opinions! It is great to be part of this community!

[TelescopeGreg]

I think either scope can be a "forever" scope, depending on what you want to do with it.  I have the 130's older sibling, and it's definitely my forever scope.  Love everything about it.  Almost.

 

The "almost" part is that I mostly do deep sky imaging, and many targets are pretty large, and pretty dim.  At 910mm focal length, many of the targets are tight.  It really needs a reducer / flattener; that would turn it into a 650-ish mm focal length f/5 scope.  For the kind of targets I image, I think THAT would be perfect.

 

The 152T has a focal length of something like 1,200mm and f/8, which is almost up into SCT territory.  Great for lunar / planetary stuff.  You could probably see and wave at the creatures on Mars.  But deep sky, probably not so much unless you like doing mosaics.  If you do decide to go this route, be sure to budget for the reducer / flattener.

[GADify]

I have an SVX127D and recently bought an SVX140T, and the difference is noticeable. If you can afford an SVX152T over the SVX130T I'd absolutely say go for it if it's permanently mounted. My 140 is heavy but I can manage it. I saw the 152T in person at NEAF and it's a biggie. I would not want to haul that thing in and out (and mount/unmount it) every night. 

 

Then I saw the AP 190 across the isle and needed to sit down. 

 

Edit - wait, was that the 180T at NEAF? [checks phone] yup. Either way it was big. LOL

Edited by GADify, 20 April 2025 - 12:41 AM.

[rgsalinger]

It's easy to reduce focal length with a reducer but impossible practically to go longer. With 2" seeing and the latest Sony chips you're imaging at almost perfect sampling in 2" seeing. If the day comes when you want to trade off detail for FOV, just put on the reducer and have fun. That's why I'd always go for the 150. My rough equivalent is exactly the scope I'd take to Chile if I could have only one OTA and it's 1107mm in focal length. YMMV

[bobhen]

Imaging is mostly about image scale. Smaller, faster refractors for wide fields and larger refractors or other scopes for larger image scale and close-up details of the planets and deep sky objects.

 

You didn't say what kind of mount you have. But if you considering a 6" F8 refractor, it must be rather robust. So, I'll offer an alternative for your consideration. You might consider the SV 130 and a Celestron C11. The SV 130 for wider fields and the C11 for image scale. You could mount them side-by-side or just swap OTAs depending on what you wanted to image.

 

Visually, the two scopes would complement each other as well. 

 

The optical quality between the two SV scopes ( the 130 and the 152) would be equal.

 

If you planned on buying a SV 152, then the price difference between the SV 130 and the SV 152 could easily fund a C11.

 

At one time I owned an AP 155 F7 and  C11. I loved that combination.  Depending on what I wanted to view or image, I mounted each scope separately. I had a Losmandy G11 and then purchased an Astro-Physics Mach One. The G11 did the job but the Mach One was the better mount. An AP Mach Two would be perfect.

 

Good luck

 

Bob

Edited by bobhen, 20 April 2025 - 08:48 AM.

[Wandering]

At present, my 80mm sits along side a Celestron 1400HD on a Paramount MEII mount with dual axis encoders. In it's current configuration (See attached pic) , I believe that I am not even utilizing half of the mounts 240lbs max payload capacity. I am musing on the idea of having the SVX152 sit along side of the 1400HD. Under ideal circumstances, I think the 80mm would be a great semi wide field scope, the 152mm a medium field scope, the 1400HD as a narrow field / planetary scope and the redcat 51 as a wides field scope. It's wishful thinking as am I sure that the mount would not be too happy to have so much equipment on it. Though all told, I believe all 4 scopes would be about 120lbs +/- 10%. I would just have to move the camera based on what target I wished to photograph.

 

I live about 80 miles east of Astro-Physics. It has been quite the temptation to pay them a visit because I came very close to buying one of their mounts years back. Needless to say, I went with the MEII.

 

 

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Edited by Wandering, 20 April 2025 - 02:38 PM.