8" vs 10" dob

I've been reading much information about different scopes. On the astronomics.com site it states a 10" dob is not very well suited for planetary and lunar viewing, especially from a light polluted location.

I'm ready to purchase a dob and I was all set to get the new Orion 10" Intelliscope but now I'm wondering if I should get something smaller. I live in a light polluted metro area (DFW) and want to view lunar detail and planets. I'm also interested in galaxies and DSOs. I know I will have better luck with some of these when I go camping and get to dark skies.

I've always heard buy the biggest aperture. The price difference between and 8" and 10" is not much. What can I expect to see with a 8" or 10" in a suburban area?

I think they say that because f/5 dobs usually have not much extension of the tube past the eyepiece so lots of stray light gets in.

I'd say go for the 10" but baffle the heck out of it -- get or make some sort of tube extension to extend the tube well past the eyepiece / diagonal zone, this will do much to cut down the ambient light getting in your eyepiece that ruins contrast in observing from a metro area. Maybe get some flocking paper too and light the inside of the tube.

Personally, I don't think that you would go too far wrong with either an 8" or 10". I wanted to build a 10" and then had really fine 8" crop up at a price that I couldn't refuse. Thus far I have been living happily ever after. I would pay more attention to the quality of the optics and the size and weight issues than anything else. There are a number of good choices, and strong opinions (mine are the only correct ones of course). I find that I can carry my 8" (38lbs) out of the study through the living room, out the door and across the street in one piece. It makes it almost a grab and go scope. When i first bough the scope it weighed 46 lbs, and I lightened it with a saber saw--that 8 lbs was a big difference in comfort. It's easier to carry out than my 5" Mak Newt on a GP mount (and slightly lighter as well). When I looked at the Discovery 10" PDHQ the weight was double. I think the Orion is somewhat lighter. In the end, it's what you are able to happily carry what distance and around what obstacles. Thus, having the garage well cleaned out or living on a third floor, is far more significant than the absolutes put forward by us blowhards.

I know globulars will look better in a 10 inch, and you should see noticeable differences in many DSO's, but nowhere near as much difference as a good dark sky will make, or even careful flocking and use of a dew shield, or really good optics vs so-so optics.

One of the main things to consider when viewing planets with medium to large aperture is the quality of the optics and the size of the obstruction. If you have superb optics with a small obstruction (less then 20%), the best planetary views I've seen are in scopes with 10 to 14 inches of aperture. If the optics in a scope are not extremely well figured or the micro finish is a bit rough or you have a scope with a larger obstruction, the detail on the planet can be a bit washed out for a myriad of reasons. In these conditions, observers may need to resort to an off-axis mask or filtration to see the detail.

The Orion scope will have decent optics, but I've never looked at planets through them. However, I'd get the 10" if I had the choice--regardless of light pollution.

The 10 inch is a suprisingly big leap in bulk and weight, so if you, say, live in an apartment, the 10 inch dob will be a big pain.

The 8-inch will be easier to take to dark skies, too. But you aren't exactly going to be taking either on a hike with you, anyway.

I'd recommend the 10-inch, too, but people seem to often be suprised at their bulk, so just keep that in mind.