Still undecided an confused about resolving power?

[justme (Cathy)]

Hello again,

So I'm still trying to figure out which scope to get.

I've narrowed it down to an 8" dob now I just have to figure out where from and which brand comes with the best inclusions and so on.

I'm looking at a Bintel which comes with a moon filter, an eyepiece tray, a cooling fan, 15 and 9mm plossl eyepieces, Crayford finderscope and dust cap (which I assumed any scope would come with?) for $499.

I'm also looking at Skywatchers which just come with the 25 and 10mm plossl eyepieces and a Crayford finderscope. Nothing else is listed as an accessory. It is $479.

Then there is a Saxon which waffles a lot about it's "tension control knob" and comes with a Crayford focuser and 25 and 10mm plossls. It is selling for $459 marked down from $499.

The specs appear much the same on all of them but the resolving power on the Skywatcher is listed as .96 while the resolving power on the other two is .56 and .58. I understand what resolving power is about, but don't know about how it is listed. Is the .96 better than the .56? Or the other way around? Is the Skywatcher being so different likely to be listed incorrectly?

Edited to add: Actually, just used my common sense and went directly to Skywatcher website to have a look. It lists the resolving power of the 8" dob as .56 so I guess that solves the problem of choosing based on resolving power.

All help and suggestions on which way to jump appreciated.

Thanks
Cathy

[PCH (Paul)]

Cathy,

the Bintel model gives a 2" ep and two 1.25" eps, plus the right angle finder scope PLUS proper collimation knobs on the primary mirror. Along with the moon filter and other bits and pieces that's a great deal at $499

You'll find the finder scope on the skywatcher a real pain in the wotsits to use, as you won't be able to get behind it properly. So that's another $80 value included with the bintel option.

[justme (Cathy)]

Thanks Paul.

I thought the Bintel sounded like a good deal but being new to this I wasn't sure. It's hard to compare when you don't really know what's useful and what's just a gimmick they've thrown in to trap the unwary.

I'm leaning towards the Bintel now.

I've certainly seen plenty of recommendations on here for Bintel's great service and so on, so it seems like a safe bet.

Cheers,
Cathy

[wasyoungonce (Brendan)]

Pretty sure the resolving power of what they speak of is the ability to resolve in arc seconds (angular resolution). That is.... ".56" can resolve objects .56 arc seconds apart or size.

Obviously smaller resolution is better although not always. In general atmospheric conditions and light pollution will scintillate the air so (and illuminate the air with scattered light on dust particles) much so that resolving below around 2 arc seconds is probably the limit of Atmospheric seeing for most.

What's best...they are all good.