Second scope? Advise please!

[tjr]

Hi all. I’m thinking of getting myself second scope to complement my existing, but I’m just tying myself in knots with getting just the right thing…

I’ve been using my current setup - SW 127 Mak on an AZ4 - for a number of years now. It’s a real joy and I’m delighted with how the whole package performs. A keeper for sure, until the distant future when I can afford to upgrade to something like a C8 : ). It’s also super compact which is an advantage living in a small London terrace house with a young family where space is a premium (hint, I don’t think the ideal second scope for me is a 20” dob!).

For a while now I’ve had a growing thirst for a scope that will give me wide-field ‘spacewalk’ views - something that my Mak just can’t deliver - and my 10x50 bins are leaving me wanting in ‘oomph’.

OK, so I *think* I’ve got a couple of scopes in mind… an ST150 and a 150pDS. Both are fast F5 scopes and both are 6”. Also, both will sit on my AZ4 (unless someone tells me otherwise for the ST150, it has proven hard to find incontrovertible evidence).

Both will be purchased second hand/astroboot as I try to do my hobby on a budget, even so the ST150 will cost more but I find myself drawn to the frac… I find myself generally drawn to fracs. Something about them just feels right. I know about CA, but I have my Mak for high power, fringe free views. Am I being irrational? Has anyone got real-life experience of both? I can’t seem to shake off the feeling that the 150pDS might be a wiser buy! Or should I be looking at another scope entirely? Would an ST120 leave me satisfied for light grasp after all? I'd like to invest in quality so should I go for a smaller ED? Argghhh!

So, I’m throwing my question out to the forum and I’m asking for your collective wisdom and experience. All opinions welcome.

[damnut]

Hi TJR,

You have opened a Pandora's box. Really bang for buck is a dob, the you could keep your Mak for planetary / grab & go.

I have both an ST120 and a Bresser Messier 152mm Petzval. Both are amazing at wide field views. The ST120 in particular has plenty of aperture for its size and it is my grab & go scope. These do suffer from some chromatic aberration (CA) around bright objects, the petzval less so with its correcting elements. The ST150 is also prone to CA. But all give a superb wide field views.

The apochromatic refractors are instruments that are particularly well corrected (withextra elements) to alleviate chromatic aberration but are more expensive. The skywatcher ED80 has a great reputation amongst  observers and imagers. For me I prefer the achro, where I can get the aperture and put up with a level of CA. But this is your decision.

Good luck with your choice.

[estwing]

8" dob...super portable..

[dweller25]

Another vote for an 8" Dob to compliment your 127 Mak

[tjr]

Interesting... I had considered this but ruled it out on the basis of physical size, have I misjudged it?

There are 200p newts regularly on astroboot, what chance that I could mount one on my AZ4? I seem to remember someone mounting a C8 on one with success so presumably the scope diameter isn't an issue...

The reservation I have for a skyline is the longer focal length. Like I said, my aim is a 'rich feild' scope to best complement the Mak.

[laudropb]

Yet another 8 inch Dob vote

[damnut]

Its too big for the AZ4 capable though it is....The c8 is a short sct. The 8" newt can be nearly a metre long!

Go for the dob to compliment your Mak.

[JamesF]

The 200P dob OTA can stand in a corner fairly unobtrusively.  If you're tight on space though I'm not sure what you'd do with the base.  The 150P dob is a little smaller but I think the base is also much the same size.

If you do have the space though, there's probably almost nothing to beat it.

I've had a lot of fun with my ST120 and one would go on your AZ4 fairly easily I think.  I get the impression that the ST150 is a bit of an animal in terms of size and weight, though I've never seen one in the flesh.  The 200P dob would leave either for dead though.

Is storage outdoors feasible at all?  That might have the twin advantages of allowing a slightly larger scope and eliminating cooling down time.

James

[damnut]

@JamesF,

Love my ST120. Bulletproof, goes everywhere. But prefer my 152mm to the DOB:-) ..But the dob would suit the op better.

[Charic]

tgr..hi there......last Week I tried to visit Regents park to meet up with the astronomers there to see if it was possible to take a look through their 10" or 12" Dobsonian if one was available, in order to ascertain whether I need to upgrade, as the opportunity will arise shortly? The cloud base was pants that night, so I never went to the venue.

On the nights they meet, you get access through the security  'Monkey Gate' then proceed to the Hub!. The gate will get unlocked for you. Check out the Widescreen centre to see when their next meet is booked. Trying before buying would make sense.

Also, an 8" Skyliner Dobsonian takes up about the same floor space as the average kitchen chair, and about 4 foot in height. Mine sits quietly in the far corner under wraps, fully protected and ready to go. If I travel, the OTA sits across the back seat and the Dob base sits on the front seat. I handle the scope very carefully and it travels with its own mattress and duvet for extra comfort / protection. A quick Barlowed laser confirms collimation and away I go, no Polar alignment, just place and view. If there are extremes between scope / ambient temperature, then a cooling period (like most scopes) ensures better  images at high powers, but nothing stopping me using the scope at low power straight away.

[swamp thing]

If space/cost is an issue how about one of the heritage line. Small, portable and at a very good price too. They will deliver superb colour free wide fields.

[tjr]

If space/cost is an issue how about one of the heritage line.

Thanks swamp thing. I did consider a heritage 130 as it could double up as a travel scope and would sit on my AZ4 at home. Ultimately I discounted it as I can manage a 150pDS and could see that being something that I would get more out of.

[tjr]

Yet another 8 inch Dob vote

Wow, there's a lot of love for this scope out there isn't there! I think I have to do some research to see if I can realistically keep a scope this size. The advantage of the 150 newt or smaller frac is that I already have a mount for them. Hmmmmmm.....

[nightfisher]

I would say get a 150 newt and this will really work on a z mount

[tjr]

I would say get a 150 newt and this will really work on a z mount

Thanks. I seem to remember you had one of these, and that you would also find yourself leaning towards fracs usually. If you don't mind my asking, how did you get on with it and why did you sell it?

[nightfisher]

Thanks. I seem to remember you had one of these, and that you would also find yourself leaning towards fracs usually. If you don't mind my asking, how did you get on with it and why did you sell it?

Yes, i had a 150p ds and a very nice scope it was, i sold it as i had bought a celestron SE alt az mount and new it was a bit to big for for this mount so i sold the 150 and bought  a 130p ds thinking this would be ok on the se, but it was not, so i kinda wish i had kept the 150.

If you can make room for a 200 dob, superb, but if not then a 150p will work very well on the AZ4 and if you are not imaging then no real need for the p ds version

[tjr]

Thanks. So it looks like a 150p is the scope for me, unless I can make space for the bigger dob. Does anyone have the exact dims of the 200p dob base?

[happy-kat]

If space is tight and it is not stored down stairs that might make it rather a pain to get out side and use it.