8" or 10" Dobsonian

I'm picking up my first scope later this month and I still cannot decide between an 8" or 10" dobsonian. Does the extra 2 inches of light gathering ability really make a huge difference?

I'm a 22 year old student, so money is a major factor in my leaning towards an 8" but if a 10" really makes a major difference I guess I can shell out the cash for it.

Any help would be appreciated,

Thanks.

Will you be moving this scope much? That would make a big difference. An 8" is on the edge of what you might call portable. As you've prabably heard, the best scope is the one that gets used.

Charlie

Pete,

Yes, the ten incher is better than the 8, and at your age, just as portable. Remember the 8 incher is probably an F6, and the 10 is probably F4.5. SO, the eight incher may be actually three inches longer.

Besides, remember that 10 inches squared is nearly half again as large as 8 inches squared--so you get a whole lot more that "2 inches."

Alex

The portability issue has been well addressed by the other respondees.

A 10" catches 56% more light than an 8".

If you are going to do most of your viewing from a relatively dark site, then the 10" is definitely the way to go.

If you're going to be doing a lot of viewing from a relatively light polluted backyard, the image in the 10" may be a bit less pleasing than in the 8". You'll still see more with the 10", but the brighter background can be annoying. To get to the background level of an 8", you'd have to bump up the magnification - which may then make the 10" dob a bit harder to use than an 8".
Renato

Hi Pete,

An 8 inch is still a lot of scope and fairly easily to handle... I bought the 8" skywatcher with the tension handles from Joe O'neil... It's a great scope... The inside is painted flat black, the inside of focuser is flat black. The end cap comes with at least a 2 inch aperature mask. It holds it's collimation really well ( I bought in June and still haven't had to touch it).. these are just a few of the NON advertized features... Canadian price was around 550.00 including tax.. (350 American )Also exchanged straight through for right angle 9 x 50 finder free of charge and had a chesire collimation tool thrown in..

At that price you would have room for a nice two inch eyepiece to boot !!

If your from out West then Manoj Sood is good to deal with along with TELHOON.

OF course if you have the money and strength then aperature always rules. The 8 inch Skywatcher is just another good alternative to think about is all.

JUST my 2 cents

Mark V