Why is Skywatcher dobsonian 8" OTA so much bigger than SKYWATCHER EXPLORER-200 ?

[tenbyfifty]

...or is it just the photographs making them look bigger?

Are they good for planets as well as DSOs?

Anybody got a pic of the 8" dob with a person next to it for scale?

[GordonCopestake]

Depends on the focal length or f/ratio. Not sure what the f/ratio's are of both scopes but if the aperture is the same then the only thing that can be different is the length of the tube. The dob has a wooden base whereas the explorer-200 is just the tube and designed to be used with a EQ mount

[The Warthog]

Looking at one of the local dealer's web pages (khanscope.com), both the scopes offered on EQ mounts are f/5, while the dob is f/6, and would therefore be about 8" longer. Either scope is probably OK for planets. My f/5 6" scope gives me a nice view of Jupiter, and people here with the 8" f/5 Skywatchers have reported good views. An acquaintance of mine has the 6" f/8 Skywatcher Dob, and it gives nice excellent views of Jupiter.

[tenbyfifty]

found a pic here: http://www.astrosurf.com/jventura/equip.htm

It seems quite dinky when you see it in the real world....

hmmmm.. a little red guy with a fork just appeared on my shoulder

[FLO]

The current 8" Skyliner (Dobsonian) tube has 1200mm focal length.

The 8" EXPLORER-200 has 1000mm.

(Your picture shows an earlier Dobsonian that was supplied with the shorter EXPLORER-200 tube)

Good optics - both of them 8)

[tenbyfifty]

What do people do when moving these things round the garden - can you pick em up and carry them

or is is best to put them on wheels? And how good at DIY do you have to be to assemble the mount -

at this point I am more trusting of skywatcher than revelation in this department but I may be mistaken?

Why are the Celestron dobbos so much more expensive - are they any better?

Why does the universe have more questions than answers? Isn't this flouting some sort of conservation law!

Have I just come back from the pub? YES!

[GazOC]

You can pick the whole scope up (base and all) in one go. They arn't that heavy.

The Celestron scopes are produced by the same manufacturer, its the same scope re-badged.

[GordonCopestake]

Skywatcher is Synta and revelation is GSO, i would say the GSO scopes have better optics but i can't vouch for eithers engineering. From what others have said the base is very easy to put together as long as Ikea flat packs dont scare you. Individually the components are not heavy you move the base and the ota seperatly. You can mount the base on a small wheeled truck if you like but most people dont need to for an 8". Once you get to 12" and higher then you might start to have problems, but 8" is fairly small and light weight really, if you are fit/strong you could probably pick it all up in one go.

[GordonCopestake]

I thought revelation was GSO gaz not synta? I could be wrong though

[GazOC]

Revelation is GSO, Celestron is Synta .

[GazOC]

I think.....

[GordonCopestake]

thats what i thunked too.... IMO GSO is better than Synta in the newt arena

[GazOC]

Yep, I'd rather a 8" f6 than a 8" f5. Theres not much size difference and the f6 will be easier on the budget eyepieces.

[GordonCopestake]

You dont want an 8" f/8.... trust me hehehe

[GazOC]

You dont want an 8" f/8.... trust me hehehe

I had to talk myself out of buying that scope more than once. I was sorely tempted.......

[FLO]

Skywatcher is Synta and revelation is GSO, i would say the GSO scopes have better optics but i can't vouch for eithers engineering.

I have owned/used both Synta and GSO....

GSO are alleged to have better mirror-sets; if so, the difference must be slight. Orion (US) switched from GSO to Synta mirror-sets ... did anyone notice?!

GSO Dobs often have 'lazy Susan' style roller bearings for the azimuth - they are OK at low/medium magnifications but a bit 'lumpy' at high mag. (Synta use standard Teflon pads).

The Synta azimuth friction adjustment works well and doubles as convenient carrying handles.

GSO Dobs have a Crayford focuser - silky smooth in use but perhaps a little out of place on a Dobsonian? The Synta rack-and-pinion focuser works well enough once the sticky Chinese grease has been replaced.

[edit] The collimation springs on the larger GSO's are a bit weak. Some of the 6" and 8" Synta tubes use rubber rings/washers in place of springs...

In truth, the differences are minor; there is no 'wrong' choice.

[GazOC]

If I was buying a 8" Dob, the focuser would probably be enough to make my mind up in favour of the GSO. The R&P is OK but if you can get a Crayford then why not?

[FLO]

Phil (Geppetto) posted a good 'fix' for the GSO bearings. If I find it, I will post a link.