Which 8" Dob??

[bbgg]

Hi All,

Great site as I am new to practical astronomy.

I am looking to get get a good quality 8" Dob to be used by myself as well as the odd night at my children's school.

I was initially looking at an 8" skywatcher black diamond adjustable scope but have been reading (and told by sales people) that you must collimate the scope every time you use it. True?

I have more recently been to the bintel shop here in melb and had a look at their 8". Seems to better build quality ?? using ball bearings on the base as apposed to the Teflon on skywatcher. Also this scope is not adjustable and is more money than a comparable item. Also, how to fit in the car??

Is there other brands/scopes I should be looking at?

Any help greatly appreciated

[Jazza11]

You can have a look at the zhumells they are fairly good quallity scopes

[stephenb]

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Hi Ben and welcome,

I can vouch for this ball bearing system on the new BinTel Dobsonian range. Much, much smoother and easier to use. You can literally push them with the tip of your little finger and they move 200% better than the older style of teflon pads.

I have owned a previous generation of Bintel Dobsonian which had teflon pads arrangement on the altitude bearings, before they changed them to the ball bearing system. They were a bit elcheapo, and I understand they were similar most other teflon-fitted imported Dobsonians.

As for collimation, my experience is a good collimation when you first set it up. Have a play and understand what/why you are doing with collimation routine.

But you shouldn't need to collimate everytime you set it up. Just a quick visual check, as it should hold collimation 99.9% unless it receives a large knock or similar. But that doesn't mean to say you cannot collimate everytime, but you'll find you won't have to.

[erick]

Yes, my experience of an 8" Bintel was that it held collimation well, even after bouncing around in the car boot for an hour.

[xnomad]

Aren't Bintel scopes just rebranded GSO equipment? I think the Sky Watcher collapsible dobs use bearings too. You can get GSO and Sky Watcher 8" for very cheap at Andrews. I'm not a dob owner but the ones that do own collapsible SW dobs have all said they hold collimation well.

[rmcpb]

It would be a toss up between the Bintel and SkyWatcher scopes. It would come down to the little extras included in your package as they would be optically very similar.

As for the collimation. It needs a quick check each session but that is just a couple of minutes while it is cooling down and would affect either scope.