The more I read, the more confused I get.

[Daz Type-R]

Hi all.

Total newbi here, so sorry for what could be a list of really dumb questions.

As my title states, I have been reading up on astonomy and telescopes etc, haveing been interested for years but not really had the time and the more I read the more confused I get.

I have looked around the site in the newbi section to try and reduce the ammount of repeat questions but can't find the answers to some. Also some advice about a 1st scope would be great.

My main concern is that I have set my sights too high, I would like to be able to see Jupiter, the cloud bands, red spot if really lucky plus the moons, as well as nebula, Andromida galaxy etc, I`m just wondering if that is poosible with the scope I have in mind for the budget I have.

I was thinking about the 8" dob: Dobsonians - Skywatcher Skyliner 200P Dobsonian as I have read the dobs are perfect for beginners. Can any body confirm if this scope (or even the 10 inch, I`m sure my budget could stretch that far) can show me the above?

Or can any body suggest something else and how big is the above scope, it's hard to tell in the picture?

Also, why to scopes need to be cold?

Sorry if these are all repeat questions, and thanks for you time.

Darren.

[russ]

The scope you have in mind is perfect and will tick all the boxes of what you hope to get from it.

The scope needs to be cold to remove the thermal currents from the tube, which degrade the image. But with this telescope, especially if stored outside in a shed or garage, it will cool very quickly when placed outside.

On nights where the seeing allows, the scope will show Jupiter in all the glory you are hoping for. And Saturn will be fantastic. Make no mistake, the Skyliner 200P is a truly superb scope that belies it's relatively low price. And that's from experience.

It's not too big or heavy. Easy to transport, fits across the back seat of an average car. Unbelievably easy to setup and use. Only downside for some is the fact it can't track and has to be nudged constantly to keep the object in view.

I personally believe, providing you don't want to image with it, there's no better scope at this price range. Plus if the planetary imaging bug does bite, you can re-mount the tube on an equatorial mount later......very easily.

[John]

I agree with Russ, these are excellent scopes - probably the best "bang for your buck" you can get currently.

They need 30 mins or so to cool from a house temperature - the warmer air in the tube disturbs the images until it's escaped and the scope has reached the outside temperature.

[Moonshane]

another vote for the 200p dob.

re cooling, think of a warm summer day, creating a heat shimmer in the distance and making everything blurry. this is very like what happens on your mirrors before they cool down.

[Daz Type-R]

Brill, thanks guys, suppose the warm air in the scope makes sense, never thought of that.

Would you also suggest 4 ep?

Haveing looked on some of the newbie stickys, it's suggested 10mm, 16mm, 20mm and 25mm, should those 4 give me a wide choice, or for the likes of looking at nebula etc will i need a wider ep?

Also, what would be the best make of ep, I`m sure quality is paramount?

Another question, mounts?

Are dobs the type of mount, i.e, the cannon type as per the link above? and are equatorial mounts similar to tripods?

Cheers.

[russ]

Widefield eyepieces are a huge boon with dobsonians as the wider field means less nudging. And the 200P will tolerate slightly lesser quality eyepieces due to its slower focal ratio of f6.

Not sure what you budget is but these eyepieces go from £20 to £600 each. As you can imagine, the difference in quality and features from each end of the scale is huge.

But there are some good value options if the budget is limited somewhat. Although remember there is no free lunch and that really does apply to astro gear. But there is also a case of diminishing returns. Some big leaps in quality at the bottom to middle range and then only very slight improvements at the top end.

[John]

The cost of the "best makes" of eyepiece may be the shocker - a number of them cost more than the price of your scope for each eyepiece !.

However good ones are available at much more reasonable prices. My suggestion would be to get the scope, a collimation tool (eg: a cheshire eyepiece as it's known, rather than the laser type) and a good guide book to the skies.

You get 2 eyepieces with the scope to get you going - there are so many choices, once you have used the scope a few times you will be able to better decide which ones next.

[Daz Type-R]

I thought the lower the focal rate the better, is that not the case or am I getting too technical for my myself?

[Daz Type-R]

Also thanks for the reply guys, much appreciated.

[russ]

Depends what you have in mind. A planetary observer will not be interested in low focal ratios at all. While for a deepsky observer or imager, low focal ratios are very important. The 200P is nicely judged for both.

In a newtonian fast focal ratios mean very large central obstructions. Very large central obstructions mean diminished contrast. Definitely not a planetary or lunar observers friend. In a very slow focal ratio scope the central obstructions are so small that they are no longer having any impact.

[Daz Type-R]

Russ, thanks for all your replys, I`m sure you get this all the time?

One last question, best place to buy all your kit from, any recomendations?

[Moonshane]

all good advice. yes, BTW a 'dobsonian' is a newtonian scope (reflector like the one we are talking about) on a mount like the one in the pic. this is a very stable but inexpensive mount and therefore the spending is in the optics. the reason they are called dobsonians is that the inventor of the original was called John Dobson.

[russ]

Ah yes, thanks Shane, should have expanded to say the dobsonian was a newtonian in a box.

One last question, best place to buy all your kit from, any recomendations?

Why not try the forum sponsor, First Light Optics. Banner at the top of the page.

[KenG]

Darren, before you do anything else, get yourself a copy of "Skywatch" by Terence Dickinson, and a copy of "Star-hopping for backyard astronomers" by Alan MacRobert, and read them. They are non-technical publications and will give you a really good overview of the hobby - telescope types, eyepieces, finderscopes, mounts, stars, the universe - which will enable you to make informed decisions about what you want to see, and the best way to see it. Don't buy a telescope, in fact, don't even go and look at any, until you've done this.

[perrin6]

Brill, thanks guys, suppose the warm air in the scope makes sense, never thought of that.

Would you also suggest 4 ep?

Haveing looked on some of the newbie stickys, it's suggested 10mm, 16mm, 20mm and 25mm, should those 4 give me a wide choice, or for the likes of looking at nebula etc will i need a wider ep?

Also, what would be the best make of ep, I`m sure quality is paramount?

Another question, mounts?

Are dobs the type of mount, i.e, the cannon type as per the link above? and are equatorial mounts similar to tripods?

Cheers.

Hi Daz,

I would suggest your highest power should be about X200 for an 8 inch which means a 6mm focal length eyepiece.

[pvaz]

If you're going for the 4 EP set, the ones that work best for me with an 8" dob are: 30mm, 15mm, 10mm and 5mm (or 7mm when seeing doesn't allow me to use 5).

So I'd cut the 20mm and get a 5, 6 or 7mm instead. 10mm is not that much for planets and moon so a bit more magnification will give you a closer look when seeing conditions allow.

Maybe it's a better idea to try the 2 supplied EPs and barlow, before you start adding gear you may not need.