Summer Musings on Telescopes

[wibblefish]

Alas my telescope hasn't had much light since mid April with one thing and another getting in the way and not having the time (nor enthusiasm at present alas!) to stay up very late / get up super early to catch what little darkness there is at present. I am hoping to catch the occasional moongazing night or get a good Fri / Sat session planned in (another limiting factor at the moment!) in the near future!

That said I am reviewing my notes and playing with the idea of what would I get if I was to get a new telescope (observing only astrophotography is far to expensive for my blood!) towards the end of the year - it must be similar to the weather related boredom I had in the winter 

So as a beginner I currently have an AZ Pronto (alu legs) with a Skywatcher 90/660 refractor, I've enjoyed a bit of everything from moongazing, planet spotting (Mars only), DSO fuzzy spotting (very faint grey blobs mostly!), some double splitting and of course the wide field star clusters have been spectacular. My garden is fairly constrained in most directions (mostly due to buildings / trees) with a fair amount of light pollution due to street lamps or neighbors security lights (Bortle 5, 20.46 SQM). I tend to have to move the telescope quite a lot throughout the night to get the right angles to avoid said lights as much as possible. The AZ Pronto does ok but its a bit over weighted in all honesty due to the BST eyepieces and can slip at times especially as I do have to angle towards the zenith quite often. 

So my options I think:

- Obviously the easiest answer is to stick with what I have and carry on learning and tinkering, especially if I am not getting much use out of it again till maybe end of July / Aug 

- Upgrade to a bigger aperture refractor, I do like the portability / storage of short tubes so maybe a Star Travel 120 or Bresser AR127-S? I guess as well as being weightier they would exaggerate any CA / SA, I get both in my little 90 but its not worried me to much so far. 

- Add a Dobsonian, probably something like the 8" Skywatcher 200P that is pretty much the staple beginners telescope rather than the 10" considering how much moving around I have to do in the garden...

- Add a Mak maybe a Skymax 102 or 127? I did enjoy the double splitting but I don't think I am really in the right location to snag many planets etc on a regular basis though. I am not sure how useful Maks are for other things such as DSO etc due to the narrow field. I guess a 102 might be able to share the same mount as my 90mm.

Any other suggestions welcome. 

In terms of other kit I have:

- Altair 1.25" Di-Electric Diagonal

- BST 8,12,18,25 1.25" eyepeices

- BST 2x Short Barlow 

- Rigel QuikFinder

- Skywatcher 7x30 RACI 

- Various filters 1.25"

Budget wise I guess I would be looking at around 400-500 though might be able to stretch to 600.

Edited June 15, 2021 by wibblefish

[Pixies]

I think an 8" dob would compliment your current scope quite well - wider field and fainter objects. Obviously you are familiar with finding objects and following them. Your current eyepieces and finders will work with both too.

I am in lighter skies than you and can see plenty with an 8" reflector.

[wibblefish]

8 minutes ago, Pixies said:

I think an 8" dob would compliment your current scope quite well - wider field and fainter objects. Obviously you are familiar with finding objects and following them. Your current eyepieces and finders will work with both too.

I am in lighter skies than you and can see plenty with an 8" reflector.

I have been leaning towards that purely since it’ll cost a lot less (even with the new prices) as I wont have to also buy a new mount. The 90 is a very good grab and go with no to little cooldown so its good for throwing out on iffy nights as well!
 

My main questions would be

- How do Dobs behave looking upward? Zenith happens alot at present! 
- Are they massively portable? I would want to be repositioning it several times a night I guess. It would also be good if they fit through a standard doorway though I can always wheel out of the garage front if needs be

- Whats the cooldown time like on a Dob?

 

Edited June 15, 2021 by wibblefish

[Pixies]

Right up near the zenith is "Dobson's hole", where many a dob user has never returned... Arghhhh! Seriously, it can be a bit awkward right near the zenith, especially trying to follow something, but I find it similar with a refractor on an alt az mount.

I don't find mine difficult to use. Like you, I have to move the scope around to different parts of the garden, depending on which part of the sky I'm trying to observe. I have a Bresser dob, and just lift the tube or of the mount and move them separately. I will occasionally move them both in one go, but only if I'm moving it several feet. I'm sure a SW is similar.

Edited June 15, 2021 by Pixies

[Pixies]

Cool-down. 30 mins in the summer, 45 in the winter. I take it out before anything else and spend most of the time faffing about getting stuff ready, like EPs, etc. I'll test the collimation too. 95% of the time it's fine and even if not, it usually just takes a minute to adjust.

[IB20]

58 minutes ago, wibblefish said:

 

My main questions would be

- How do Dobs behave looking upward? Zenith happens alot at present! 
- Are they massively portable? I would want to be repositioning it several times a night I guess. It would also be good if they fit through a standard doorway though I can always wheel out of the garage front if needs be

- Whats the cooldown time like on a Dob?

 

I love my 8” 200P dob and its footprint is fairly small, 52cm I think when pointing towards the zenith so I’ve got it just in my kitchen.

The eyepiece position is really good for zenith viewing, maybe not so much if you are >6 foot but you could always elevate the base e.g. with a water butt stand. Lining up zenith targets can be awkward as I have a telrad and straight through finder, a right angled finder would no doubt make this easier but I just find using a telrad quicker and am still quite flexible.

It weighs about 26kg; I wouldn’t say it’s incredibly portable but I can lift and move it a few metres at a time. It’s an awkward shape which makes carrying it as one something I wouldn’t want to keep doing in a session. In separate parts as tube and base it is very easy to move however. 

I’d say cool down can be about 20-30 mins in summer and 45-70 mins when it’s colder. Viewing on patio concrete probably causes me more issues than actual tube cooling, it might faster acclimated if I observed on turf.

[wibblefish]

Thanks for the info both!
 

Yeah zenith viewing on my refractor is a pain mostly because of the mount head as it tends to overbalance. I need to build a custom counterweight really to help stop that! 
 

To be honest I can probably cutdown my moves by planning better but thatll come with experience of what I can see when.

[Tiny Clanger]

5 hours ago, wibblefish said:

Alas my telescope hasn't had much light since mid April with one thing and another getting in the way and not having the time (nor enthusiasm at present alas!) to stay up very late / get up super early to catch what little darkness there is at present. I am hoping to catch the occasional moongazing night or get a good Fri / Sat session planned in (another limiting factor at the moment!) in the near future!

That said I am reviewing my notes and playing with the idea of what would I get if I was to get a new telescope (observing only astrophotography is far to expensive for my blood!) towards the end of the year - it must be similar to the weather related boredom I had in the winter 

So as a beginner I currently have an AZ Pronto (alu legs) with a Skywatcher 90/660 refractor, I've enjoyed a bit of everything from moongazing, planet spotting (Mars only), DSO fuzzy spotting (very faint grey blobs mostly!), some double splitting and of course the wide field star clusters have been spectacular. My garden is fairly constrained in most directions (mostly due to buildings / trees) with a fair amount of light pollution due to street lamps or neighbors security lights (Bortle 5, 20.46 SQM). I tend to have to move the telescope quite a lot throughout the night to get the right angles to avoid said lights as much as possible. The AZ Pronto does ok but its a bit over weighted in all honesty due to the BST eyepieces and can slip at times especially as I do have to angle towards the zenith quite often. 

So my options I think:

- Obviously the easiest answer is to stick with what I have and carry on learning and tinkering, especially if I am not getting much use out of it again till maybe end of July / Aug 

- Upgrade to a bigger aperture refractor, I do like the portability / storage of short tubes so maybe a Star Travel 120 or Bresser AR127-S? I guess as well as being weightier they would exaggerate any CA / SA, I get both in my little 90 but its not worried me to much so far. 

- Add a Dobsonian, probably something like the 8" Skywatcher 200P that is pretty much the staple beginners telescope rather than the 10" considering how much moving around I have to do in the garden...

- Add a Mak maybe a Skymax 102 or 127? I did enjoy the double splitting but I don't think I am really in the right location to snag many planets etc on a regular basis though. I am not sure how useful Maks are for other things such as DSO etc due to the narrow field. I guess a 102 might be able to share the same mount as my 90mm.

Any other suggestions welcome. 

In terms of other kit I have:

- Altair 1.25" Di-Electric Diagonal

- BST 8,12,18,25 1.25" eyepeices

- BST 2x Short Barlow 

- Rigel QuikFinder

- Skywatcher 7x30 RACI 

- Various filters 1.25"

Budget wise I guess I would be looking at around 400-500 though might be able to stretch to 600.

You may recall that I started with a heritage 150 dob, which I still use much of the time , if no Moon or planets are showing themselves, it is the 'scope I take out. Short cool down, decent light gathering, and the simplicity and stability of the base just works, no faff. Bad points : low alt objects can be unavailable to it because it has a low viewpoint, and my fence gets in the way. High magnification can mean a lot of precision nudging to keep targets in view too. As with any newt, you get stars which have diffraction spikes, which some folk dislike..

Would I buy a full sized dob ? Yep, in a heartbeat. The Bresser 8" (200mm) would be my choice: it is a little more expensive than the skywatcher equivalent, but it seems better made, with nicer accessories and a superior alt bearing . It also seems it may be a bit lighter than the SW one, altho' reports of the skywatcher weight vary (while Bresser publish their measurements ) Bressser base 9.5 kg, tube  11.5kg ,  SW  tube officially 11kg, and the base I've seen given as anything from 12kg to 17kg. The lighter weight would contribute to ease of getting the dob outside, so another point for the Bresser.

However ... for the Moon, and planets, the longer focal  length of a mak is great,  as is having the 'scope on a mount with slo mo controls . The SW 102 mak  is sold by FLO bundled with a pronto mount , so I'd be confident the mount you already have would be fine for the 102, while the 127 mak at a bit over 3kg really needs a more substantial mount like the AZ5, pushing the price up.  Cool down takes a half hour or so, and dew on the corrector plate can be a pain,  but with the mak design doing clever origami on the light path, you have a compact 'scope with a long focal length.

If I was starting again , knowing what  I do now of what works for me practically, , I think I'd go for a bigger dob (200mm not 150mm) and a smaller mak (102mm not 127mm ) because using the mak only on bright objects I don't think I'd miss the extra aperture, but it would make a difference to DSOs in the dob.

However ... I've used my cheap second hand ST80 more often since I bought it than I have either of the other two 'scopes :  If I'm waiting for the mak to cool, or when there are brief gaps in clouds, and quick daytime forays out to look at today's sunspots , the ST80 is out, tripod extended and in use in a matter of moments.  I've enjoyed using it to the point where I am keen to try a step up to a 102mm frac  So, whatever you buy next, keep hold of your 'frac too !

Heather

 

[wibblefish]

13 hours ago, Tiny Clanger said:

You may recall that I started with a heritage 150 dob, which I still use much of the time , if no Moon or planets are showing themselves, it is the 'scope I take out. Short cool down, decent light gathering, and the simplicity and stability of the base just works, no faff. Bad points : low alt objects can be unavailable to it because it has a low viewpoint, and my fence gets in the way. High magnification can mean a lot of precision nudging to keep targets in view too. As with any newt, you get stars which have diffraction spikes, which some folk dislike..

Would I buy a full sized dob ? Yep, in a heartbeat. The Bresser 8" (200mm) would be my choice: it is a little more expensive than the skywatcher equivalent, but it seems better made, with nicer accessories and a superior alt bearing . It also seems it may be a bit lighter than the SW one, altho' reports of the skywatcher weight vary (while Bresser publish their measurements ) Bressser base 9.5 kg, tube  11.5kg ,  SW  tube officially 11kg, and the base I've seen given as anything from 12kg to 17kg. The lighter weight would contribute to ease of getting the dob outside, so another point for the Bresser.

However ... for the Moon, and planets, the longer focal  length of a mak is great,  as is having the 'scope on a mount with slo mo controls . The SW 102 mak  is sold by FLO bundled with a pronto mount , so I'd be confident the mount you already have would be fine for the 102, while the 127 mak at a bit over 3kg really needs a more substantial mount like the AZ5, pushing the price up.  Cool down takes a half hour or so, and dew on the corrector plate can be a pain,  but with the mak design doing clever origami on the light path, you have a compact 'scope with a long focal length.

If I was starting again , knowing what  I do now of what works for me practically, , I think I'd go for a bigger dob (200mm not 150mm) and a smaller mak (102mm not 127mm ) because using the mak only on bright objects I don't think I'd miss the extra aperture, but it would make a difference to DSOs in the dob.

However ... I've used my cheap second hand ST80 more often since I bought it than I have either of the other two 'scopes :  If I'm waiting for the mak to cool, or when there are brief gaps in clouds, and quick daytime forays out to look at today's sunspots , the ST80 is out, tripod extended and in use in a matter of moments.  I've enjoyed using it to the point where I am keen to try a step up to a 102mm frac  So, whatever you buy next, keep hold of your 'frac too !

Heather

 

Thats an interesting thought I guess now the SW and Bresser are not so far apart in price now. I vaguely remember some negative point on the Bresser being to do with mounting brackets and positioning for say RACI but I'd have to research it.

Ah good point on the 102, I think that was my original choice for a telescope before the stock problems happened! That could be a good way to go if I get to the business end of the year and decide I can't afford the Dobsonian route. I was thinking though is there that much difference between a refractor and Mak at such small apertures, do I want to spend £200 to find out

I honestly love the little frac, it stays in the garage with the tripod ready to go, it probably takes me more time to sort out my gear than it does to chuck it outside! I could do with mounting it a little more robustly in all honesty, but adding another tripod and mount head is going to be more than the original telescope package so it seems a bit pointless unless I was upgrading it or getting something like a 127 Mak  

Edited June 16, 2021 by wibblefish

[Tiny Clanger]

I believe the Bresser finder shoe on some 'scopes is not the usual fairly standard one, but replacement shoes can be bought which have slots rather than holes for fixing, so can fit a range of existing spaced holes. The Bresser dob might have a standard shoe and a Bresser/Explore Scientific type one as well, I'm not sure . I'm trying not to yearn for one too much .... the lead times are so very long ....

The 102 mak has a focal length of 1300mm in a small body (not sure exactly how small , but my bigger 127 has a focal length of 1500 mm in a tube 320mm long) a refractor of that focal length would actually be close to that physical length itself , and therefore be that bit harder to mount properly ... a quick look suggests the Bresser  102L at  1000mm focal length for a fairly similar price to the mak for comparison https://www.firstlightoptics.com/bresser-telescopes/bresser-messier-ar-102l-1000-refractor-ota.html

Every 'scope type has strengths and limitations, which is why I need three 🤪  , and actually have a 4th en route ....

Heather

[Pixies]

The Bresser has a ES-style finder mounting bracket, but you can swap it out quite easily for a Baader universal which will allow you to use the usual Sinta style ones. I have lots of black nuts and bolts which are the correct sizes to fix the bracket to the tube, so if you ever go down that route, give me a shout and I'll post some to you. The Bresser focuser is a big leap in quality over the standard Skywatcher and makes using a DSLR pretty simple, too.

The AZ Pronto mount suffers with having the dovetail clamp on top, so the scope's centre of gravity causes it to fall back as you near the zenith. A mount like the AZ5 has it mounted on the side which allows you to find a good balance point and not have to worry about it tilting.