Portability counts - SW ST102 or ST120??

[emadmoussa]

Hola,

I've been thinking about adding another medium power refractor to my kit. I am after a portable scope that I can grab and set up quickly and still get good views. My SW 200p reflector is heavy and not very easy to move around, and my ST80, even though pretty good in terms of portability and basic observing and acting as a guide scope, I still need a little bit more light gathering and magnification power.

I'm aiming for the Skywatcher Startravel 102 or 120...I'm kind of inclined to get the ST120 as it's got more light gathering capacity, but my main concern is the increase in weight. Is it considerable in comparison with the 102? Is the scope worth it based on the reasons mentioned above?

Please note I don't need any EPs or mounts or anything like that, I already have this stuff. Just the OTA matters for what I need.

Thanks!!

[Tiago]

Well, I'm waiting for delivery on a 120 myself. Portability did come to mind, but the difference in weight seems to be differ from source to source

www.astroshop.eu - 3,48 for the 102 OTA vs 4,0 for the 120 OTA

www.teleskopservice.de - 2,2 for the 120 OTA, 3,9 for the 120 OTA

When choosing, I wasn't intimidated by weight - these are short refractors, after all. And the size isn't going to be that different too. I guess it depends on what you are going to mount it on - I chose an AZ4.

[Tiago]

Oh by the way, that was Kg for us metric people

[Tiago]

And I meant

"www.teleskopservice.de - 2,2 for the 102 OTA, 3,9 for the 120 OTA" - gahh, I hate not being able to edit posts - please merge, nuke, whatever

[emadmoussa]

And I meant

"www.teleskopservice.de - 2,2 for the 102 OTA, 3,9 for the 120 OTA" - gahh, I hate not being able to edit posts - please merge, nuke, whatever

True, I'm not worried about the weight either. I'd mount it on my EQ5. Still, size counts though. Keep me updated please.

[JamesF]

The ST120 feels and looks an awful lot bigger than the ST102. I wouldn't say it's particularly heavy though. I carry it already attached to my AZ3 over one shoulder and I can carry the lot with one hand. Probably the length is more of an issue than anything else.

James

[emadmoussa]

The ST120 feels and looks an awful lot bigger than the ST102. I wouldn't say it's particularly heavy though. I carry it already attached to my AZ3 over one shoulder and I can carry the lot with one hand. Probably the length is more of an issue than anything else.

James

Yep, the length is what matters the most. How long is it?

[JamesF]

Yep, the length is what matters the most. How long is it?

With the focus tube fully wound in and dew shield in place, about 660mm. The ST102 is about 110mm shorter.

James

[damnut]

Hi There,

The best grab & go scope I have owned was an st120 on an az3, az3 mount just man enough so long as you keep the bolts tight. Length about 60 cm as it is f5 (add a bit for the dew shield). Used to go in the boot, roofbox or on the back seat. Impervious to rain,snow sand and dog slobber.

Enjoy your scope.

[emadmoussa]

With the focus tube fully wound in and dew shield in place, about 660mm. The ST102 is about 110mm shorter.

James

Thanks James, how do you compare deep space observation between ST102 and ST120?

[John]

These are great scopes for low to medium power widefield observing and both are portable enough. If your main interest is planetary viewing with them though there are better options I feel. These F/5 achromats develop quite a lot of chromatic aberration and their objective lenses are not that accurately figured which make them less effective as the magnification increases.

If your main purpose is deep sky / widefield exploring though they make a lot of sense as the above issues have much less imact on low to medium power views.

[JamesF]

Thanks James, how do you compare deep space observation between ST102 and ST120?

Given the choice of the ST102 and ST120 I'd probably take the 120 every time. I loved using the 102, but unless I specifically needed something small the ST120 definitely beats it for wide field use.

James

[emadmoussa]

These are great scopes for low to medium power widefield observing and both are portable enough. If your main interest is planetary viewing with them though there are better options I feel. These F/5 achromats develop quite a lot of chromatic aberration and their objective lenses are not that accurately figured which make them less effective as the magnification increases.

If your main purpose is deep sky / widefield exploring though they make a lot of sense as the above issues have much less imact on low to medium power views.

I already have a SW 200p, which produces great planetary viewing. And yes, deep sky is my main interest. Thanks for the advice!

[John]

I already have a SW 200p, which produces great planetary viewing. And yes, deep sky is my main interest. Thanks for the advice!

In that case definitely go for the extra aperture then !

If you get a 120mm scope under really dark skies it's amazing how well it can do on deep sky objects

My ED120 refractor has shown me a mag 12.4 supernova from my back garden - I was pleasantly surprised that I could see that "deep" with it !

[JamesF]

These are great scopes for low to medium power widefield observing and both are portable enough. If your main interest is planetary viewing with them though there are better options I feel. These F/5 achromats develop quite a lot of chromatic aberration and their objective lenses are not that accurately figured which make them less effective as the magnification increases.

If your main purpose is deep sky / widefield exploring though they make a lot of sense as the above issues have much less imact on low to medium power views.

Absolutely agree with this. My second hand 127 Mak is compact, convenient and will stomp all over either of these for planetary viewing, but the ST120 certainly does the job for wide and I was quite happy with it until aperture fever caused an itch I had to scratch.

James

[emadmoussa]

Thanks! I think I'll go for the ST120.

[Tiago]

I just got my 120ST (Orion brand, same tube, different paint) in the mail. Sadly, the retailer forgot the acessory package that should have beeen included and sent the OTA only, which sucks

They told me they're going to make it right, but that means a few more excellent nights down the drain.

Anyway, the OTA is surprisingly light - the AZ4 mount is FAR heavier and beefier. It's not too long, and that includes a 6"-8" dew shield. I can't gauge the optics yet (missing everything apart from the OTA and mount), but overall the quality of the finish seems good so far.

Ah well, first light for this one will have to wait...

- Tiago

[emadmoussa]

That's a shame! I guess you'll have to wait a bit longer for your first light. Worth the while. Keep me posted

[steve_bham]

I've got the 120mm ST And its def a keeper. I can fit the OTA in a sports bag and carry the mount so very portable.

I'm going to upgrade the mount to az4. Although the az3 is totally cable of carrying the 120mm I just want something beefier and these cloudy nights are meant for spending!

M42 was the best I've seen it from the 120mm

[Tiago]

Well, the whole user-end optics are missing (diagonal, eyepieces, finder etc..) but the guys and girls from the store were pretty cool about it and told me they are going to send them tomorrow. It might have been a problem with the supplier, since that stuff should have been included in the box.

The skies have been pitch black until moonrise, I was really looking forward to testing it out. Oh well...

[Tiago]

Steve, how's the view with the 5mm EP? I'll need to get a decent EP for the occasions when I'm on a moon/planetary mood.

[steve_bham]

Steve, how's the view with the 5mm EP? I'll need to get a decent EP for the occasions when I'm on a moon/planetary mood.

Very good. On Jupiter very little CA but on moon the CA is noticeable. So I'm going to get a semi apo filter for the occasions I view the moon.

I'd like to try the 2.5mm eyepiece to see how it performs.

[JamesF]

I'd like to try the 2.5mm eyepiece to see how it performs.

If you have a 2x barlow you could always barlow up your 5mm ep. My experience is that the ST120 isn't very happy at such high magnifications though.

James

[steve_bham]

If you have a 2x barlow you could always barlow up your 5mm ep. My experience is that the ST120 isn't very happy at such high magnifications though.

James

I don't really get on with barlows, don't know what it is just don't find the view and pleasing.

So I tend not to Barlow any eyepiece,

Might order the 2.5mm as its only £49 if worst comes to worst could use it as a double star splitter!

[JamesF]

My preference is not to use them for visual, too. Barlowing up the 5mm might give you some indication of whether it was worth getting the 2.5mm though. My gut feeling is that you'd probably decide it's not worth it with the ST120.

James