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Which second telescope to get?


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I have a Skymax 127 that I use for visual astronomy only (I've no plans for astrophotography). I'm very happy with it, accepting that it has a narrow FoV and so is best used to observe smaller objects needing higher magnification. With this limitation in mind, I've been considering adding a second scope to cover wide field observing.

I like the EP configuration on the Mak as it allows me to stay seated while observing just moving my seat around the tripod, and because of this I don't think I would get on with a Newtonian, particularly a larger wide aperture one. So I've been considering refractors since these have the same EP configuration as the Mak. I have the Mak on a SynScan AZ GOTO mount and was planning, at least initially, to use this mount for the second scope which limits me to 5kg. I also have a 2" visual back on the Mak and was planning to swap over the existing back end (1.25" diagonal / filter wheel / EP holder) to the second scope.

With these things in mind, and looking at a budget of £200 - £350, I'm considering these scopes:

Sky-Watcher Evostar 72ED DS-Pro - this seems to be well corrected for CA, but is it a bit small for DSOs, and is it mainly aimed at astrophotography?

Sky-Watcher Startravel 102 - this seems to have a good sized aperture (about as big as the AZ GOTO mount will handle), but will CA be an issue, and is the standard focuser OK or will I need to shell out for the dual-speed upgrade (which is almost as expensive as the scope?

Bresser AR-102XS / 460 - this has the same aperture as the ST102 but is more compact with a shorter FL (wider FoV), but is the CA any better / worse, and like the ST102, does it really need the dual-speed focuser upgrade?

 

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The Evostar 82 is indeed a fine scope well liked for astrophotography although still a good visual scope but it is only 72mm aperture.

The Bresser 102 XS is better optically than the Startravel 102 with less CA and much better build quality and a great focuser. The focuser is the weak point of the Startravel 102.The dual speed knob is a recommended upgrade as it makes fine focusing much better and is simple to install.

The Startravel 102 however can be picked up second hand fairly cheaply. but as you mention replacing the focuser makes it much less of a bargain. 

Edited by johninderby
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Honestly, i would put my £300 budget in a safe place and keep adding to it, until finally i could afford one of those beautiful Starfield 102 ED's from FLO. You would not regret it, and its amazing how quickly budgets increase when we stop spending our loose change on take aways and other none essential stuff.

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25 minutes ago, Dave scutt said:

What about a dob🤔

I've come to realise that I need to sit with a comfortable EP position and really observe an object for several minutes. With the Mak I can cant over the diagonal and get a comfortable EP position while seated, and that position doesn't change much as I slew the scope, other than having to move my seat (a kick stool, on casters) around the base of the tripod. I just don't see how that would work with a Newtonian. I also don't like the way Newtonian's are open ended and there is their need for collimation.

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19 minutes ago, mikeDnight said:

Honestly, i would put my £300 budget in a safe place and keep adding to it, until finally i could afford one of those beautiful Starfield 102 ED's from FLO.

The Starfield 102 looks very nice but it's three times the price (I could get a triplet for the same money) and it has a FL of 714mm so has much less FoV than the other scopes I mentioned. I notice that its focuser is similar to the Bresser AR-102XS though.

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Ah but you did mention the possibility of needing to upgrade the focuser on one of the cheap achromats, which starts to add to the cost. I'm not sure I'd go for a triplet that's priced in the same range as the Starfield 102. Often a doublet ED is prefered as a visual only instrument. The image will be visually Apochromatic and it will be lighter and cool quicker than a triplet. And although low power wide fields are beautiful, its often when middle to higher powers are used that DSO's really become spectacular. I've owned and used numerous cheaper end rich field refractors around 4" aperture and haven't seen any that could compete with a modern F7 ish ED doublet. The only outstanding small aperture rft's have been high end, such as those by TeleVue, Takahashi Sky 90, and WO Megrez. Honestly, before you do buy a Startravel (the ST150 is spectacular but heavy), taking a look through a 4" F7 might dispel any doubts.

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An Altair Starwave Ascent 102ED f7 refractor for £495 would for visual, be a better choice than all the scopes mentioned in the opening post, although at 4kg plus accessories it would just be under the limit of the intended mount's payload. Others would have to chip in regarding the suitability of the combination.

Below is a pic comparing the fov through a 1.25" 24mm 65° eyepiece using a Skymax 127 and a 102mm f7 refractor.

astronomy_tools_fov.png.803434149ce3dfb3626153bc1758b483.png

 

If you can afford £350 max then waiting a bit, £500 will be in reach. The versatile 4" refractor will make the Skymax 127 redundant anyway,  so simply sell it to recoup the extra cost. 😉

Edited by ScouseSpaceCadet
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Another one for the Altair Starwave Ascent 102ED. Brilliant little scope which I mostly use on an AZ5.

I bought one about 6 months ago after reading the views of others on here and have been ridiculously pleased with it.

I planned for it to be just a quick grab n go but I’ve ended up favouring it far more than that. Even over my 150 SkyMax.

They do show up in the classifieds occasionally too.

 

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What exactly do you want the widefield refractor for? The CA may not matter on some targets. I have a Startravel 102 and use it mainly for dabbling in EEVA imaging and imaging of DSOs.  The focuser is not that bad for visual use, and I added a low-cost helical focuser accessory for imaging.  I have used it on a SLT mount (probably the same mechaincs as your 127mm Mak mount)

Of course, if you spend more money, you can buy a better instrument. 🙂 

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1 hour ago, Cosmic Geoff said:

What exactly do you want the widefield refractor for?

For taking in the likes of M45. I feel like I'm peeping through a keyhole with the Mak.

But I'm also hoping that the resulting bigger exit pupil will make a difference on the likes of M31. With the Mak I know I can't take in the whole galaxy but so far I can only see the central section anyway (as a white blob) which easily fits into the FoV of the Baader Zoom at 24mm (less than 0.7 degrees). Same with M33, most of the time its too feint for me to see at all!

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If it is for low magnification views of big stuff like the Pleiades and M31, then a StarTravel isn't a bad idea. I used to use an ST80 for the same purpose and it was capable of giving lovely views of those sort of targets.

Edited by Ags
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On 21/11/2021 at 20:15, ScouseSpaceCadet said:

An Altair Starwave Ascent 102ED f7 refractor for £495 would for visual, be a better choice than all the scopes mentioned in the opening post, although at 4kg plus accessories it would just be under the limit of the intended mount's payload.

I think the Altair will be too long for the mount, and may weight too much when accessories are added (the Mak is 320mm long and weighs 3kg). Also the Altair, with a FL of 714mm, will only increase the TFoV from 1.04° (for the Mak) to 2.18°, whereas the Bresser AR-102XS will take it up to 3.39°, and the Evostar 72ED will take it up to 3.71°.

I think I'm always going to use the Mak to observe anything small and anything that benefits from high magnification, since that's what it's designed to do. The gap I'd like to fill is at the wide field end of things, and unless I'm missing something, that also means low magnification.

Reading this long thread on Cloudy Nights, the general consensus seems to be that the Bresser AR-102XS is good for visual astronomy provided that you don't go beyond x50 magnification when CA becomes a problem. For larger nebulae I'm likely to be using a UHC filter anyway which, I assume, removes any CA, and I assume I could also reduce CA by stopping down the aperture.

On 22/11/2021 at 07:52, Ags said:

If it is for low magnification views of big stuff like the Pleiades and M31, then a StarTravel isn't a bad idea.

The ST102 doesn't seem to offer any advantage optically over the Bresser, it's longer and weighs more, and has a less good / more expensive to upgrade focuser.

The Evostar 72ED would give me the widest TFoV and with APO performance, but the 72mm aperture rather than 102mm might be a down side given that it's intended use is for feint objects.

If I were to stop down the Bresser to 72mm that would reduce its CA while maintaining the 460mm FL and therefore the TFoV.

So at the moment I'm liking the Bresser, in the absence of anything better and affordable with a short FL.

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Fair dos... If you're interested in expansive dsos though, are your skies decent? Would you not consider binoculars? In Bortle 3 a few weeks ago on one night I ticked off several nebulae, star clusters etc with just 10x50s and no filters... At home I gave up trying with my current and previous instruments. 10x50s, 130P, ST120, 150P, 200P, 102 Mak and 102ED all useless at nebula observation with severe light pollution. 🙄

Edited by ScouseSpaceCadet
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6 minutes ago, ScouseSpaceCadet said:

Fair dos... If you're interested in expansive dsos though, are your skies decent? Would you not consider binoculars? In Bortle 3 a few weeks ago on one night I ticked off several nebulae, star clusters etc with just 10x50s and no filters... At home I gave up trying with my current and previous instruments. 10x50s, 130P, ST120, 150P, 200P, 102 Mak and 102ED all useless at nebula observation with severe light pollution. 🙄

I live in the countryside in a Bortle 4 area so light pollution is minimal here. I am still struggling to see nebulae though!

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  • 4 weeks later...

P1060204.thumb.JPG.e0b0fc29d22905c332420a17250ca4a8.JPG

Following up on this post, I've bought a TS Optics Photoline 72 / 432 APO. Less aperture than the Bresser AR102XS but with proper glass and about the same FL, so the same wide field.

It arrived this afternoon and feels very well built. I've set the focus control vertically so that I can more easily get to it at higher elevations. It could be set horizontally but then the balance point isn't quite right and its hard to get at when the scope is pointing vertically. In daylight the image looks very sharp, sharper I would say that through the Skymax 127. I can't wait to check it out at night!

Edited by PeterC65
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I have been following this thread with interest as I'm in the same boat with the SW127 and considering a wide-field/shorter focal length scope to complement it. Thanks for the update on which scope you eventually went for. Looks good in any case. Clear skies.

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On 21/11/2021 at 17:45, PeterC65 said:

I've come to realise that I need to sit with a comfortable EP position and really observe an object for several minutes. With the Mak I can cant over the diagonal and get a comfortable EP position while seated, and that position doesn't change much as I slew the scope, other than having to move my seat (a kick stool, on casters) around the base of the tripod. I just don't see how that would work with a Newtonian. I also don't like the way Newtonian's are open ended and there is their need for collimation.

I'm a big refractor fan (I own three) but just be aware that whilst the MAK folded design is very forgiving to your EP position, a longer refractor  (like my ED150) can soon get you in an awkward position, particularly for higher altitude targets. You may need to consider a tripod extension depending upon which refractor you opt for.  For outreach events my ED80 is by far the favourite scope for general viewing.

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22 hours ago, PeterC65 said:

I've set the focus control vertically so that I can more easily get to it at higher elevations.

I tend to leave my fine focus side pointed downward on both my 72ED and 90 APO.  That way, I'm generally coming in at it with my fingertips from underneath rather than the sides of my fingers from over top.  It looks like you might not have enough clearance with your mount at zenith to do this, though.

Enjoy that scope.  I had debated getting it as an upgrade to my 72ED (FPL-51 doublet), but decided to upgrade my aperture to 90mm at the same time.  The triplet part was just a bonus as one showed up used for a great price.  I did find out that 90mm triplets acclimate as slowly as 127 Maks and 8" Dobs though. 🙄

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I think as a complementary scope to the Mak fast achromat should work fine. At lower powers for DSO CA isn't much of an issue, and for higher powers you already have the Mak. I use 120mm StarTravel as a complementary scope for my 12" Dob and love it for that purpose. 

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Hi Peter,

Moving back in the thread, you mention collimation on a reflector.

To be honest I have seen far more written about collimation than I have had to do - since getting my first newt in 2003.
I have owned quite a few newts since then.

Once set up they tend to stay good for a long time. OK if you take it down cobbled streets in a solid tyre wheelbarrow, it moves.
I recently carried a well collimated 12" fast newt 120 miles in a car with manual handling at both ends of the journey.
When tried at the new location, with one man (bumpy) handling it was still well collimated.
If you re-assemble after a complete dismantle (focusser and mirrors removed) yes there is work to do. But nothing arduous.
Just line up one bit at a time.
The nice thing is that you can carry out collimation in the warm house, in daylight.

Most of the time in the UK, the sky transparency and stability, rather than the scope, limits the viewing so if the scope is a bit off, so what.

I'm suggesting that collimation is not a reason to dismiss a newtonian reflector.
Carrying, storing and mounting a big tube, or moving around for the view, may be reasons to go against this scope type.

You could pick up a used 6" newt for not much money and give it a try.
If you like it, great, if you don't sell on (hopefully at little loss) and you have more information about your next scope.

HTH, David.

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On 21/11/2021 at 17:28, mikeDnight said:

Honestly, i would put my £300 budget in a safe place and keep adding to it, until finally i could afford one of those beautiful Starfield 102 ED's from FLO. You would not regret it, and its amazing how quickly budgets increase when we stop spending our loose change on take aways and other none essential stuff.

Fine advice Mike, but knowing you and your take aways it seems a case of do what I say and not what I do.  Otherwise you would have a TSA 120 by now 😄.

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Heritage 150 with your excellent 24mm ES 68 in there...our H130 never needs the sec collimated, ever and the primary needs a minor tweek now and again. Easliy shows the Merope neb (and more) in the Pleiades and many many nebula. Mounts well on a tripod too. These scopes might surprise you.

Edited by jetstream
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