Can I use a Barlow lens on a Saxon 8" dob

[outbacknick]

Hello all I have just purchased a Saxon 8" dob and have been told that I can not use a Barlow lens on this scope is this correct? I would appreciate the help thanks nick

[torana68]

dont know about cant? is there a model number? cant might mean not high enough quality mirror to use the higher magnificaiion with some eyepieces, other than that dunno, who said cant and did they quantify their answer in any way?

[Rockah]

That seems a bit odd - "can't"? I don't see why you couldn't? Have you got a model number for the dob that someone can look up? If it's one like this, I don't see any reason why you couldnt http://www.ozscopes.com.au/dobsonian-telescope-saxon-8inch.html

It could be a focus issue, but that'd be about it. Seems to have a 2inch focuser with a 1.25 inch adapter so looks pretty normal.

[outbacknick]

Hi yes it is the one mentioned I now think he means that because I have a 5mm eyepiece that I can't get any higher magnification.would that be correct?

[torana68]

possibly, could be as I said a not so high quality mirror. Any quoted specs on the mirror?

[Stu Ward]

You certainly can use a Barlow with the 8",
But at 5mm your magnification without the Barlow will be X240. This is difficult to get good viewing in all but the most perfect conditions.

When you use the Barlow (x2 i guess) then you are up to X480 Mag.
You would need to be in a very dark sky, with very little atmosphere motion or pollution.

In normal skies everything in the viewfinder will be wobbling around like a Jelly.

Look at an late evening high mag view of the moon to see what i mean

Stu