New scope

[Beulah]

43 minutes ago, Dayleh said:

Are there any cons to a collapsible dob?

 Adding to Estwing's comment and fully agreeing to it!

Other disadvantages to consider is the truss poles have a slight side-to-side play in them when retracting the top portion of the scope (once the poles are fully retracted and screws tightened, they are rigid). This means more collimation, meaning the scope needs checking and collimating every time. When I was using the solid tube 8" (200p), I would check collimation every time and it seemed that I only had to make adjustments one in every three sessions!

It has not been a problem with me (well, I lie, it bothers me sometimes); larger apertures sometimes need a bit more attention!

The other thing to think about is having to acquire a light shroud to prevent stray light from getting onto the primary. Again, not a problem with me, I just got my sewing machine out... 

If I could do it all again I'd plump for the full truss telescopes for the larger apertures so I can throw it in the car to access a super dark site...anything lower than 14" would be a solid tube...

[CraigT82]

You could also consider getting the 8" version (skyliner 200p) it's £150 cheaper so would leave cash for a couple of decent EPs and a cheshire eyepiece (if you don't already have one).  The 8" is an f6 compared to the f4.7 of the 10", so it's easier on eyepieces (optical aberrations of EPs become worse the faster the scope).

[Jimtheslim]

53 minutes ago, CraigT82 said:

You could also consider getting the 8" version (skyliner 200p) it's £150 cheaper so would leave cash for a couple of decent EPs and a cheshire eyepiece (if you don't already have one).  The 8" is an f6 compared to the f4.7 of the 10", so it's easier on eyepieces (optical aberrations of EPs become worse the faster the scope).

This is good advice. I have not used an 8" but very nearly went for one. Having the spare change and a winder range of eyepieces to choose from (as they are a little more forgiving) would be nice. However I knew deep down that if I did I would always wonder if spending the extra money would have been worth it. I occasionally wonder if I should have gone up to a 12" and wish I had, that is until I start lugging everything in and out the garden room at which point I think the 10" is absolutely spot on.  

[Louis D]

1 hour ago, estwing said:

Any over a 12" are quite heavy 

If you were answering the question of collapsible dob disadvantages, then weight would be an advantage over solid tube designs.  I've helped lug a 17.5" inch Coulter solid tube dob out of the back of a full size van, and I can tell you it is both very heavy and awkward to move.  On the other hand, a similarly sized modern 18" truss dob is not a problem for a single person to wheel out with wheelbarrow handles and set up.

To answer the question about collapsing dob disadvantages, there is some possibility the primary will need to be collimated more often than a solid tube design.  It is also a more expensive design.

[estwing]

2 hours ago, Beulah said:

 Adding to Estwing's comment and fully agreeing to it!

Other disadvantages to consider is the truss poles have a slight side-to-side play in them when retracting the top portion of the scope (once the poles are fully retracted and screws tightened, they are rigid). This means more collimation, meaning the scope needs checking and collimating every time. When I was using the solid tube 8" (200p), I would check collimation every time and it seemed that I only had to make adjustments one in every three sessions!

It has not been a problem with me (well, I lie, it bothers me sometimes); larger apertures sometimes need a bit more attention!

The other thing to think about is having to acquire a light shroud to prevent stray light from getting onto the primary. Again, not a problem with me, I just got my sewing machine out... 

If I could do it all again I'd plump for the full truss telescopes for the larger apertures so I can throw it in the car to access a super dark site...anything lower than 14" would be a solid tube...

Won't read a better post on the subject....

[estwing]

23 minutes ago, Louis D said:

If you were answering the question of collapsible dob disadvantages, then weight would be an advantage over solid tube designs.  I've helped lug a 17.5" inch Coulter solid tube dob out of the back of a full size van, and I can tell you it is both very heavy and awkward to move.  On the other hand, a similarly sized modern 18" truss dob is not a problem for a single person to wheel out with wheelbarrow handles and set up.

To answer the question about collapsing dob disadvantages, there is some possibility the primary will need to be collimated more often than a solid tube design.  It is also a more expensive design.

Sorry I thought collapsible dob was being in the skywatcher type not a truss like mine...and I can just about put mine in the back of a car 

[CraigT82]

1 hour ago, Jimtheslim said:

This is good advice. I have not used an 8" but very nearly went for one. Having the spare change and a winder range of eyepieces to choose from (as they are a little more forgiving) would be nice. However I knew deep down that if I did I would always wonder if spending the extra money would have been worth it. I occasionally wonder if I should have gone up to a 12" and wish I had, that is until I start lugging everything in and out the garden room at which point I think the 10" is absolutely spot on.  

Yeah I can agree with that. No matter what size scope you go for, you will always have those 'what would I see if I'd gone even bigger' thoughts! That my friend is aperture fever and there is no known cure ?.

It's often said that an upgrade of one scope size (ie 8" to 10") is not worth doing. The extra aperture would give you slightly finer lunar/planetary detail for the eagle eyed on very good nights, but the extra light gathering power would be barely noticeable for DSOs, especially for the beginner observer. People generally say to go up two sizes minimum (which roughly equates to a 1 magnitude increase in the scopes limiting magnitude). 

 

[Charic]

I bought a couple of Televue Delos in preparation for my new 12" solid tube, which are not so easy to come by these days.

The scope has still not arrived, not sure it will for a while yet, and i'm sure a 10" would be just as good, but I would still opt for the slightly bigger  12"

They say from a dark site?.......... well my 8" Skyliner is no exception, its truly a different beast, without any light pollution, and given that more aperture can work better on  fainter objects, its my assumption that I would benefit a 12" over a 10" from my garden, yet have the burden of moving the 12" in a smaller car, to some of my darker sites. There's just no satisfying some of us folk, nothing is straight forward with this amazing hobby.

[Louis D]

36 minutes ago, CraigT82 said:

Yeah I can agree with that. No matter what size scope you go for, you will always have those 'what would I see if I'd gone even bigger' thoughts! That my friend is aperture fever and there is no known cure ?.

It's often said that an upgrade of one scope size (ie 8" to 10") is not worth doing. The extra aperture would give you slightly finer lunar/planetary detail for the eagle eyed on very good nights, but the extra light gathering power would be barely noticeable for DSOs, especially for the beginner observer. People generally say to go up two sizes minimum (which roughly equates to a 1 magnitude increase in the scopes limiting magnitude). 

 

I use the rule of roughly doubling diameter size between scopes.  I have a 72mm refractor, an 8 inch tube dob, and a 15 inch truss dob.  The differences between each are quite noticeable in observing, weight, and setup ease.  I tend to use the two smaller scopes more than the big one due to the latter two reasons.  I know I can get better views, but it's a lot more work to get them with the big scope.