6" or 8" or 10" Dobsonian

ddakers · Guest

I am trying to determine how much I will be able to see from my light polluted backyard with a 6-8-10" dobsonian. I know planets and star clusters will not be a problem, but will I be able to see many DSOs? Will I see just as much in a 6-inch dob as I can see in a 10-inch dob given the light pollution?

Jne_K · Site Admin Joined: 24 Sep 2003 Posts: 5621

Hi

You could make an argument either way, but, all else equal, the 10" scope is going to offer the most performance, even in a light-polluted area. In other words, the 10" will get you more performance, but will lose more of its potential. Just dpends on how much light pollution we are talking about, here. Unless portability is an issue, though, I would still go for the 10" if you can afford it.

ddakers · Guest

I should have stated in the original post that in my area the best you can see is magnitude 3 with the unaided eye. Does this change your recommendation at all?

Jne_K · Site Admin Joined: 24 Sep 2003 Posts: 5621

HI

That's about what I deal with, but I would still opt for the 10", if for no other reason that you may find yourself observing from another location, someday. Even here in the Chicago area suburbs, though, you can see an improvement when going to a larger scope on deep-sky objects. I have experienced this at many an astronomy club outing and when observing with friends. The oft repeated idea that big scopes are useless in the city is overstated. Light pollution may affect a big scope more than a small scope, but I don't believe it will ever completely eliminate the advantages of the big scope. Then too, big scopes handle aggressive LPR and nebula filters better than a small scope and filters are quite useful for fighting light pollution. I still say go with the big scope if you can afford it and portability is not an issue.
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