Hi Jowel,
Hmmm, looks like those answers require my services again, please see below;
Quote:
Originally Posted by Jowel
Just looking at the specifications for the Sky Watcher 200mm dobsonian, solid tube (SW680)...
Focal length is 1200mm. Is that decent? Some other 8" telescopes have it more? Would more be any better? This is fine, more than I have with my 200mm BDN200, which is only 1000mm.
Eyepieces listed are: S20, S10(31.7mm). What the hell does this mean? And are these decent eyepiece sizes to start off with? They are a 20mm and a 10mm eyepiece. Which in this scope give you magnifications of 60x and 120x respectively. The 31.7mm refers to the barrel size which equals 1 and 1/4 inches (standard focuser size).
Focal ratio is "f/6". I have no idea what this means? Focal ratio is the result of the equation FL of scope divided by the aperture. In this case 1200mm/200mm equals 6. Therefore F6. Small Focal ratios of F6 and below mean the scope is "fast" which gives bright images in a WIDER field than in a longer FL scope such as a compund scope or refractor where the FL can be F7, to F15 (normally a Schmidt Cassegrain). MORE focal length means you can theoretically magnify much more, BUT the view is narrower.
Finderscope is 9 x 50. What? This is the little telescope mounted on the main barrel of the scope which you look through to point the mainscope to the object in the sky you want to "find" in the main scope. Hence the name "Finderscope". The 9 x 50 refers to the magnification level (9x) and the aperture (size of the scope - 50mm). This is a good finderscope.
Barrel diameter is 50mm/31.7mm. What? The focuser accepts 2 inch (50mm) as well as 1 and 1/4 inch (31.7mm) eyepieces. This is normal and good also.
Also, would this dobsonian telescope easily connect to an equatorial mount if I buy one later? Yes, you take the tube off the base (unscrew the two handles - thats it.) You will have to buy some tube rings later (which wrap around the tube and hold it) and a dovetail bar which these two rings screw into and then the dovetail bar is held onto the EQ mount head. When you do get to that stage, an HEQ5 is perfect for this (what I have)
Yes, I'm definately a beginner  Any help guys? |
Also, dont get too hung up on the details and worry that this 8" scope may not be the BEST one you can get now. There is ALWAYS going to be a better scope or a different scope which you will understand later is referred to as "scope envy" and this manifests itself in you also as "aperture fever" which means you are always on the lookout for a larger and larger scope.
The main reason that the 8" dobsonian has been recommended so highly to you is that its is REALLY easy to use for a beginner. The Skywatcher brand is great quality and value for money. Also, as explained, it is doubly good to be able to upgrade this to mount it on an EQ mount later.
Dont sweat it, you'll be fine.
Cheers
Chris