Minimum diameter for DSO?

[zoneca]

Hi, I don't know which scope to chose if I want to observe dso for at least 1/3 of the fov? Please suggest any scope but not a dob, because I cannot find any dob retailer in my country (indonesia). And what is the minimum diameter & f length for this purpose? Does it concern to f ratio aswell?

Thx.

[brantuk]

You can view dso's with most any scope - but the bigger diameter the better and the more and deeper you'll see. If this is your first scope then the 200P is hard to beat for a good value all round "view of everything" starter ota. Just pop it on an NEQ6 or HEQ5 if you don't fancy dob mounting. And with fl-1000 at f-5 it has great imaging potential too.

[zoneca]

Thanks brantuk. Today I just found out that there is a seller of skywatcher 12" here. I think I'm gonna get this one for fulfilling my curiosity to see the dso by my own eyes...

[E621Keith]

Thanks brantuk. Today I just found out that there is a seller of skywatcher 12" here. I think I'm gonna get this one for fulfilling my curiosity to see the dso by my own eyes...

The Skywatcher 300p dob will be very nice. However, if you have never observed DSO before, just remember they are all fuzzy grey blobs and look nothing like what you see in photos.

[Stargazer_00]

12" dob will last you a lifetime, too. Just ensure your expectations are measured. Look at people's sketches/hand drawn representations of DSOs to get a feel for what to expect at the eyepiece.

Bear in mind that it is your eye, not the telescope, that is the limiting factor here. If we had eyes that could soak up photons over time we'd see the DSO exactly as you see them in books. But we can't

[zoneca]

No wonder I saw m42 in greyscale with my newly bought 12" dob. I was so lucky to be able to spot m42 in my first jurney last night. Most of the people said that galaxies are best viewed at lower power ep like 25mm, but I think the appearances of the galaxies will be very small for my eye to notice. Seeing m42 is consider small enough, how to use it even for more further galaxies? No point if the appearance only as a dot.

[mdstuart]

Galaxies are large objects so many appear larger than a dot in a 10mm eyepiece.

Have a go at spotting M65/M66 under leo. They are bright for galaxies and its nice to see them in the same field. Start with the 25mm eyepiece.

You are looking for two VERY dim grey smudges one of which is next two a star. They are MUCH harder to see than the orion nebular but they are much bigger than a dot!

Amazing though to see other galaxies millions of light years away with the naked eye.

Mark

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