8 inch dob or 80mm apo?

[doublevodka]

I find myself going round in circles so looking for some opinions from people who've had both if possible?

First the background, I'm a visual observer and likely to stay that way, I usually have limited time so quick setup and go is important to me. I love the az-gti for this, up and running in minutes, but I find myself hankering for a wider field of view than the skymax 127. The az-gti is also a plus for finding objects quickly.

I have been nearly there with the apo decision, a skywatcher 80ed specifically as generally comes with a 2 inch diagonal and eyepiece and a nice field of view, but then I've seen a well priced 8 inch gso dob locally and I'm a bit torn, many of the YouTube channels I like heavily recommend a dob, so should I just bite the bullet and go manual with a larger scope?

I have had a couple of long fl refractors and do like the contrast they provide.

My budget would be max £400 which would get me a used 80ed or a dob and change, any opinions gratefully received 👍

 

[Peter Drew]

I would go with a 8" Dobsonian any time.  It will show you much more than any of your previous telescopes.  Easy to use, easy to set up and adding a StarSense system would enable you to find things.  🙂

[bomberbaz]

2 minutes ago, Peter Drew said:

I would go with a 8" Dobsonian any time.  It will show you much more than any of your previous telescopes.  Easy to use, easy to set up and adding a StarSense system would enable you to find things.  🙂

Exactly what he said and this one specifically StellaLyra 8" f/6 Dobsonian | First Light Optics

There is a recent-ish thread about best 8" dobs and a lot of people were throwing their weight behind this scope, I was one of them.

[Peter Drew]

Nice to have a 80mm APO as well.     🙂

[bomberbaz]

1 minute ago, Peter Drew said:

Nice to have a 80mm APO as well.     🙂

don't flip flop peter 😉

[scarp15]

Yes as the others have said, both possibly, as they are complementary but certainly begin with an 8" dob.

[doublevodka]

31 minutes ago, Peter Drew said:

I would go with a 8" Dobsonian any time.  It will show you much more than any of your previous telescopes.  Easy to use, easy to set up and adding a StarSense system would enable you to find things.  🙂

Have to admit I do like the idea of StarSense, just not the price of Celestron's own dobs..

[doublevodka]

26 minutes ago, Peter Drew said:

Nice to have a 80mm APO as well.     🙂

Indeed it would, sadly my equipment ambitions far outweigh my current budget 🤣

[doublevodka]

30 minutes ago, bomberbaz said:

Exactly what he said and this one specifically StellaLyra 8" f/6 Dobsonian | First Light Optics

There is a recent-ish thread about best 8" dobs and a lot of people were throwing their weight behind this scope, I was one of them.

Have to admit this one would be top of my list, very well spec'd for the price, quite possibly the best mass market one out there

[Ricochet]

I own an 8" dob and a 72ED. Eventually owning both scopes would be ideal but if for some reason I could only keep one scope I would keep the 8" dob. Without wanting to stir up any frac vs newt debates it's just better on all targets (that fit in the field of view).

Both scopes are relatively quick to set up. The Bresser dob mount has holes that can be used as hand holds and so I can pick up both scope and mount as one, lift it out of the shed and put it down in the garden ready to observe. That's a two handed, power from the legs type of lift. The things that slow it down are going back to the shed to get the adjustable observing stool that is a necessity given the eyepiece height, and carrying the increasingly heavy eyepiece case that really needs splitting into two sets. For planetary observing there is some cool down time required but for lower power DSOs you can just get straight on with it. With a 28mm Nirvana I can get about 1.8° which is just large enough for targets like the Pleiades or double cluster, but a 9x50 RACI is needed for manual finding.

If, however, I do not feel like lifting the weight of the dob then I can use the 72ED. This is a much more lightweight setup although not necessarily any quicker to set up. This lives in the house in its case which has room for three 1.25" eyepieces. I can carry the case in one hand and the mount in the other and take them outside together. Once assembled the scope and mount can be lifted with one hand. As the limited selection of eyepieces are in the scope case I don't need a second trip for the eyepiece case and the tripod allows me to either observe standing or adjust the height for a garden chair so there is no need to open the shed for the observing stool. If I want maximum field of view then using 2" accessories opens the field up to about 5° but typically I have found that the 3.8° given by a 24mm 68° eyepiece is sufficient and helps with balance. With such a wide field of view no separate optical finder is required. Cool down is pretty non-existent on a 3" doublet. Maybe a few minutes are needed by it's not really noticeable. The 80ED is a bit bigger and heavier but I expect it would be similar to use.

[dweller25]

13 hours ago, doublevodka said:

Have to admit this one would be top of my list, very well spec'd for the price, quite possibly the best mass market one out there

That would be a very good choice 👍

[bosun21]

8” dobsonian definitely. You will be able to see a great deal more in the sky especially if your skies are relatively dark. There’s really no contest on which is best when it comes to a 203mm scope versus an 80mm. What you should try and do is to look through a few of these scopes at an astronomy club or meeting, and I am pretty sure you would come to your conclusion quickly. Good luck with whichever you choose.

[Alan White]

14 hours ago, doublevodka said:

Indeed it would, sadly my equipment ambitions far outweigh my current budget 🤣

I think that applies to many others, myself included.

On your question, the answer is not quite as clear cut in my book and I have both types of scope and have owned an ED80 in the past as well.

For grab and go with no thermal cooling issues as will be a problem, the 80mm wins hand down, but only for the maximum of half an hour.
Then the Newtonian is far better value as its bigger apperture wins as does the focal ratio.

But you mention the ease of finding things with the GOTO that you will forgo with a fully manual Dob,
which in my book is not a problem, but I have been looking upwarsd for very many years and like manual finding and manual mounts.

I think the real initial answer only you can provide.
The question firstly is, Will you enjoy manualy finding things and tracking?
Then the second question of which of the choices you make becomes easier.

But my biased answer is get the Dob and go find things, concentrates the observing somewhat.

Hope this helps rather than hinders.

The Stella Lyra scope is well made and good value, smooth in action, I played with the range at the IAS last year.

Edited February 26, 2023 by Alan White

[Naughty Neal]

 Another 8" Dob candidate is the offering from Ursa Major and a ton under the Stellalyra asking , though the Lyra spec is a it better hence the price differential.  Raci finder , superview plossal and dual speed focuser.  One expects it depends on how tight the budget is.

Edited February 28, 2023 by Naughty Neal
spelling

[IB20]

I have both an 8” dob and 76mm APO, quite frankly I love and need both. I’d say eventually get both, but if it’s for quick, wider viewing, you probably want the APO. Had the dob out a few evenings ago and it was great, but this time of year in the UK, I’m looking at a good 60-90 minute cooling time for it to be at its best; the views are stunning though.

I’ve probably used the 76mm 10 times the amount I’ve used the dob in the last observing year. In fact it’s more likely double that when I think of my white light solar viewing too. 

Edited March 1, 2023 by IB20

[RT65CB-SWL]

Also dependent on whether you want to travel with a 'scope, spend more time viewing than setting up, etc.

[Mr Spock]

There's a huge performance difference between 200mm and 80mm. I'd go for the Dob without hesitation.

I keep my 12" in a shed, so it's almost grab and go 

[Stu]

On 25/02/2023 at 22:04, doublevodka said:

I find myself going round in circles so looking for some opinions from people who've had both if possible?

First the background, I'm a visual observer and likely to stay that way, I usually have limited time so quick setup and go is important to me. I love the az-gti for this, up and running in minutes, but I find myself hankering for a wider field of view than the skymax 127. The az-gti is also a plus for finding objects quickly.

I have been nearly there with the apo decision, a skywatcher 80ed specifically as generally comes with a 2 inch diagonal and eyepiece and a nice field of view, but then I've seen a well priced 8 inch gso dob locally and I'm a bit torn, many of the YouTube channels I like heavily recommend a dob, so should I just bite the bullet and go manual with a larger scope?

I have had a couple of long fl refractors and do like the contrast they provide.

My budget would be max £400 which would get me a used 80ed or a dob and change, any opinions gratefully received 👍

 

This is one of those questions that I think needs more info before answering. What are your circumstances? Do you have somewhere convenient to store the dob? Can you physically manage to lift the dob, easily enough that it won’t be a deterrent to use? What are your favourite observing targets? What are your skies like? What are you eyes like?

Its very easy just to say ‘get the Dob’ and I’m not disagreeing that they give significantly better views of DSOs than an 80mm, but as they say, the best scope is the one you use most. How often has the forum wisdom of ‘get the Dob’ led to people ending up with a big lump of a scope they don’t use much? We don’t know but I bet it happens. I reckon more than 80%+ of my observing is with a 100mm scope, probably 15% with a 200mm and 5% with a 400mm, very roughly.

If widefield views are a favourite for you, or your observing habits are largely made up of short 15 to 30 minute sessions then the 80mm may serve you better. If you can handle the dob, want some great views of a wide range of targets and have time to put it out to cool and enjoy the session, why not get the dob?

How about the dob and something like a cheap ST80 for widefield/quick sessions as the best of both worlds?

[doublevodka]

48 minutes ago, Stu said:

This is one of those questions that I think needs more info before answering. What are your circumstances? Do you have somewhere convenient to store the dob? Can you physically manage to lift the dob, easily enough that it won’t be a deterrent to use? What are your favourite observing targets? What are your skies like? What are you eyes like?

Its very easy just to say ‘get the Dob’ and I’m not disagreeing that they give significantly better views of DSOs than an 80mm, but as they say, the best scope is the one you use most. How often has the forum wisdom of ‘get the Dob’ led to people ending up with a big lump of a scope they don’t use much? We don’t know but I bet it happens. I reckon more than 80%+ of my observing is with a 100mm scope, probably 15% with a 200mm and 5% with a 400mm, very roughly.

If widefield views are a favourite for you, or your observing habits are largely made up of short 15 to 30 minute sessions then the 80mm may serve you better. If you can handle the dob, want some great views of a wide range of targets and have time to put it out to cool and enjoy the session, why not get the dob?

How about the dob and something like a cheap ST80 for widefield/quick sessions as the best of both worlds?

Lots of good answers and opinions in here but @Stu probably has raised the most on on-point questions so I'll answer them as it may help someone else with a similar dilemma in the future.

I store all my current scopes in the shed (so cooling time is very minimal), so whatever is added would join them. I previously owned an 8 inch on a eq3-2 and could lift that fully assembled at a push (with the counterweights) so I don't think a dob would be an issue. It went in the end because the mount was not up to the task and was frustrating to use but I did enjoy the views when I could get it on target. Targets - like a bit of everything really. Skies - Bortle 4. Eyes - ok, only need reading glasses, not needed for observing.  Sessions are a mixture from 30 mins to a couple of hours.

Having just picked up a RACI for a bargain price I have to admit I'm leaning towards your idea of dob and ST80 although picking up the latter used seems fairly difficult (so people must like them), will need to sell some bits first to keep the wife on side, but I'm pretty sure I know what I'm going to get rid of.

The StarSense idea raised above by @Peter Drew has also got me thinking. Having previously owned a Nexstar 4SE I know I like their way with software, yeah it was a bit clunky, but "Tonight's Best" was really useful to me, easier to access that the Synscan version and gave better info. Having looked at StarSense Explorer more I really like the look of it, seems right up my street so I may have to DIY it in future.

Thanks to everyone who's contributed so far, really appreciate the effort 👍

 

[Stu]

52 minutes ago, doublevodka said:

Lots of good answers and opinions in here but @Stu probably has raised the most on on-point questions so I'll answer them as it may help someone else with a similar dilemma in the future.

I store all my current scopes in the shed (so cooling time is very minimal), so whatever is added would join them. I previously owned an 8 inch on a eq3-2 and could lift that fully assembled at a push (with the counterweights) so I don't think a dob would be an issue. It went in the end because the mount was not up to the task and was frustrating to use but I did enjoy the views when I could get it on target. Targets - like a bit of everything really. Skies - Bortle 4. Eyes - ok, only need reading glasses, not needed for observing.  Sessions are a mixture from 30 mins to a couple of hours.

Having just picked up a RACI for a bargain price I have to admit I'm leaning towards your idea of dob and ST80 although picking up the latter used seems fairly difficult (so people must like them), will need to sell some bits first to keep the wife on side, but I'm pretty sure I know what I'm going to get rid of.

The StarSense idea raised above by @Peter Drew has also got me thinking. Having previously owned a Nexstar 4SE I know I like their way with software, yeah it was a bit clunky, but "Tonight's Best" was really useful to me, easier to access that the Synscan version and gave better info. Having looked at StarSense Explorer more I really like the look of it, seems right up my street so I may have to DIY it in future.

Thanks to everyone who's contributed so far, really appreciate the effort 👍

 

Sounds like the Dob would be quite manageable and worthwhile then, and if you can find an ST80 or similar then that would be the cherry on top! 👍

[Carbon Brush]

My first proper scope, almost 20 years ago, was an 8" reflector on EQ.
Since then I have owned various scopes, but always had a biggish reflector in the collection.

A used 8" dob won't set you back too much, giving a good start on saving up for the next scope😁

[doublevodka]

1 minute ago, Carbon Brush said:

A used 8" dob won't set you back too much, giving a good start on saving up for the next scope😁

This is my thinking currently, although I'm about 6 scopes into the "next scope", the astronomers curse 😂

[Guest]

A 8 inch dob could be a lifetime scope and is for many people.  Given the choice i always opt for aperture so the 8 inch is a no brainer for me. I would add a setting circle and angle gauge to make finding stuff easy. 

[faulksy]

dob would be the best. but like peter drew said 80mm apo would be good. you could use that as a finder or counter weight 🤣

[Xilman]

2 hours ago, faulksy said:

dob would be the best. but like peter drew said 80mm apo would be good. you could use that as a finder or counter weight 🤣

Don't knock the counterweight proposal.  Two scopes on the same mount have a long and productive history. Both can be used at the same time, with different filters perhaps, or  one as a guidescope , or separately where one is more suited to the target than the other.

FWIW, I have three scopes on the same mount, not counting a small and crude finder. The reflector is used for deep sky, photometry, etc. The 120mm achromat for lunar and planetary, and the 80mm apo for solar.  None of them are counterwieghts because the mount is a fork, not a GEM.