Second scope advice

[Greg6498]

I am thinking about a second scope to accompany my 8” dob! I would like a doublet with an EQ mount. I want it for planetary observation. I will also have to choose a reasonably priced EQ mount. I also want to be able to use my 2” eyepieces. Is that even possible? I thought maybe an 80-100 but the price really jumps as you go bigger! Any advice would be appreciated!

[vlaiv]

What would your budget be?

I truly believe that your 8" dob will be better planetary scope than an 4" refractor (many will not agree on this).

Since you are interested in second lighter scope - how about going with something relatively short and good for both planets and wide field, while being portable? That way you will extend usability of second scope next to 8" dob.

In that case, I would say 4" F/7 ED doublet like this:

https://www.altairastro.com/Starwave-102ED-FPL53-Refractor.html

Another option would be tried and tested SW 100ED - a bit longer scope at F/9 so a bit less of wide field with it and not so portable (but lighter than above scope)

If you don't want to go with portability and wide field option, you have this scope that will excel in planetary role:

https://www.altairastro.com/Starwave-ASCENT-102ED-F11-Refractor-Telescope-Geared-Focuser.html

This is long refractor being F/11 and 1100mm FL (tube is bound to be at least that long - so you need bigger / heavier mount for it).

All above offer 2" focusers.

P.S. I see you are in the states - in this case - have a look at this one as F/7 4" portable ED apo scope:

https://optcorp.com/products/stellarvue-sv102-access-f-7-doublet-refracting-telescope

(I think it might well be the same scope as Altair Astro above - same specs and very similar looking scope).

[Ben the Ignorant]

Since you are concerned with price the least expensive 4-inch doublet (I assume you're talking apos and semi-apos) I know of is this one:

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p4964_TS-Optics-ED-APO-102mm-f-7-Refraktor-mit-2-5--R-P-Okularauszug.html

When TS issued their FPL-53 4-inch f/7 doublet (which is a clone of the Stellarvue Access) priced at 990€, they had to lower the price of the FPL-51 doublet to keep it competitive, so it went from 762€ to 599€.

My own 80mm FPL-51 f/7 doublet shows very little violet fringing because it's small diameter and it's fitted with a violet-absorbing dielectric diagonal. Paired with a 9mm Myriad the chromatism vanishes, but the 4.7mm Explore enhances it a bit, so it's not all in the objective. There is no better deal out there than the TS 102 for those who are happy with a semi-apo, except if you search the used market, of course.

And you don't have to worry for your 2-inch eyepieces, all recent apos and semi-apos take them, even the tiny 60mm scopes.

[Prador]

What about an Altair astro 102 ED f11? There's a lot of talk on CN about it but only one actually being used. Not a big sample by any means but the feedback is from an experienced visual astronomer.

For planetary viewing, if you dont want to spend $6-800 on the scope alone, a similar or bigger aperture maksutov on a decent Alt-Az might be an option. 

[Sunshine]

I'm guessing its a portability factor only, the 8' dob will provide great planetary views. i'ts one thing if you have a 12' dob then, dragging it out to peek at a planet will be an issue. Your 8' unless you feel otherwise is still kind of square in the  "yes its a dob but small enough to justify taking it out for a quick peek at saturn" range. Having said that, who am i to tell you what scope you need or don't need, after all, find one person here with one scope only, good luck with that.

[SIDO]

I would suggest a shorter focus ed doublet not ultra short like 400mm but more like 500 or 600mm,s with an aperture of about 4"s, include a lightweight alt az tripod and you have a good all rounder grab & go you can then use for solar with the many available filter options out there. 

I won't suggest a specific scope for this but others certainly will and without my hesitation of course ?

                Good to see you are getting furthure along Greg, Best of Luck and Clear Skies...

                          Freddie...

[mikeDnight]

8 hours ago, Greg6498 said:

I am thinking about a second scope to accompany my 8” dob! I would like a doublet with an EQ mount. I want it for planetary observation. I will also have to choose a reasonably priced EQ mount. I also want to be able to use my 2” eyepieces. Is that even possible? I thought maybe an 80-100 but the price really jumps as you go bigger! Any advice would be appreciated!

Hi Greg,

The price really jumps as you get better too! A 100mm SW achromat won't beat your 8" Newtonian as a planetary scope, but a 100mm Tak definitely will. The Tak though is an expensive item but is probably the best 100mm visual refractor currently available. Three other options immediately spring to mind though. A 100mm SW DS Pro is a terrific scope that will give superb lunar and planetary views. For a little more outlay you might consider the 120mm DS Pro, which will give a sharper view of the moon & planets than your 8", but is no longer than the 100mm version. Then there's the new 102ED F11 Star Wave,  if you fancy a classic longer focal length refractor. At F11 a GP style mount would still carry it well! 

You might also consider looking for an SW ED on the second hand market!!

 

[mikeDnight]

4 hours ago, Sunshine said:

I'm guessing its a portability factor only, the 8' dob will provide great planetary views. i'ts one thing if you have a 12' dob then, dragging it out to peek at a planet will be an issue. Your 8' unless you feel otherwise is still kind of square in the  "yes its a dob but small enough to justify taking it out for a quick peek at saturn" range. Having said that, who am i to tell you what scope you need or don't need, after all, find one person here with one scope only, good luck with that.

I've got "one scope only," and it kicks like a mule! ?  

There's always one isn't there?!

 

[Paul73]

The 100mm SW ED should be a good bet. I’ve owned the 80mm and the 120mm versions. The 80mm was nice and portable, but just didn’t have the grunt for planetary. The 120mm had the power but lacked the portability. So 100mm ....

Compared with dobs. Image scale is always going to be an issue with affordable quality fracs. But, the image is super super sharp.

Paul

[John]

Having been in the same situation as you a few years back, I feel that a 4 inch short focal length refractor would be a good compliment to your 8 inch dob. For quite a while I ran an 8 inch dob and a 4 inch F/6.5 refractor on a simple alt-azimuth mount as my scope "fleet" and between them I had a lot of fun.

Don't expect the dob to get outclassed by the refractor on the moon and planets though. Thats not my experience even now that I own a Tak like Mike does

I'd also advise keeping the mount for the 2nd scope simple - if the setup time for the frac becomes an issue it kind of defeats one of the objectives for it and the 8 inch dob will get used more.