Skywatcher Skyliner 10" or 12" Dob?

[Stormwatch]

Hi all, I've been looking at Dob prices lately and the Skywatcher range is by far and away the cheapest around, yet it always seems to get good reviews so I'm happy to go with them.

I noticed there is now a new 12" version available for £530, compared to the 10" for £350.

Question is: is the extra 2" really worth the extra £180? I could get an exceptional eyepiece for that £180!

I tend to think I'd be better off getting the 12" as the 10" will probably be crying out for an upgrade in six months time. But still, that £180 is a significant extra amount of money for what seems a small extra aperture gain....

[Stormwatch]

One more thing - will I need a dedicated observing chair for use with a big Dob like this? I understand they're very big 'scopes!

[Akyra]

I find it most confortable to use a simple dining room chair, or a collapsable camping chair is ideal!

Its only uncomfortable when looking straight up (should you ever need to....)

[Stormwatch]

Thanks Akyra, I have been using a simple plastic garden chair for use with my Celestron refractor, I guess that will do the job. I was worried I'd be up and down constantly with such a big 'scope.

[Astronut]

That extra 2" brings in 44% more light than the 10"

I'll be ordering a 12" Skyliner dob very shortly but the 10" seems to be the more popular choice. Bear in mind that the 10" mirror will have a shorter cool-down (thermal stabilisation) time than the 12" but I have no idea by how much. I believe the 10" mirror is made from pyrex glass too which has a lower thermal expansion coefficient and lower specific heat ie. it cools down quicker than plate or bk7 glass.

Here's a link explaining the different types of glass used in mirror manufacture: http://www.oldham-optical.co.uk/Glass.htm

A cooling fan can always be fitted to speed things up if needed.

BTW they're not that big on a dob mount - here's some pics of the 10" and its owner: http://stargazerslounge.co.uk/index.php?topic=12684.0

[Stormwatch]

Thanks for the links, that guy's HUGE though! Sizes of scopes is always a hard one to judge for beginners I think - it's easy to adjust a tripod for a refractor, but that's not possible with a dob so it's a big worry for potential buyers who don't have a local showroom to look in for scopes.

That extra 2" brings in 44% more light than the 10"

I'll be ordering a 12" Skyliner dob very shortly but the 10" seems to be the more popular choice. Bear in mind that the 10" mirror will have a shorter cool-down (thermal stabilisation) time than the 12" but I have no idea by how much. I believe the 10" mirror is made from pyrex glass too which has a lower thermal expansion coefficient and lower specific heat ie. it cools down quicker than plate or bk7 glass.

Here's a link explaining the different types of glass used in mirror manufacture: http://www.oldham-optical.co.uk/Glass.htm

A cooling fan can always be fitted to speed things up if needed.

BTW they're not that big on a dob mount - here's some pics of the 10" and its owner: http://stargazerslounge.co.uk/index.php?topic=12684.0

[Whippy]

I popped into Green Witch on Saturday and they had a 16" Meade Lightbridge set up, that's a big scope!

[GazOC]

12" is a pretty noticable step up visually from a 10".

[SteveL]

I popped into Green Witch on Saturday and they had a 16" Meade Lightbridge set up, that's a big scope!

The big white one in the corner... which takes up the ENTIRE corner

[Whippy]

That's the (big) boy. Impressive thing, you'd need to get a step ladder for that! Makes everything else in there look decidedly dinky. £1500 for it isn't that much for it really!