Mr Yoshida's Refractor Rankings

[Louis D]

31 minutes ago, Andrew_B said:

I think you'd struggle to get the best out of a big scope of any kind here in the UK compared to many places in the US.

I'm sure that's what's going on.  During the dead of summer here while we have a stationary high pressure dome parked over us for months (can you say drought?), the seeing is rock steady and temperatures drop slowly at night.  As such, it's quite easy to bump up the power on large Dobs to have the same exit pupil as that of a smaller frac.  Under these conditions, it is so much easier to make out fine planetary details at the larger image scale and higher theoretical resolution of the big Dobs than in nearby fracs.  UK seeing conditions are probably the dominant reason for the lack of popularity of big Dobs there.  They would probably just show a boiling mess of turbulent atmosphere.

[John]

Well that generated some interesting comments

I'd never heard of these ratings before so my post was in good faith and not intended to stir things up

I'm very happy with my scopes, even the ones that are "off the chart"

 

 

 

 

[John]

22 hours ago, RobertI said:

Interesting John. I wonder where the Skywatcher 120ED would come on his table?

Mr John says 70 points

[dan_adi]

On 15/10/2021 at 05:00, Louis D said:

I look at it this way.  If you've got $10,000 to spend toward getting the best planetary views, a decent sized Dob with a Zambuto mirror will blow the doors off a similarly priced APO and quality mount on most nights here in Texas.  Perhaps things are different in the UK, but I've always been underwhelmed by the planetary views through high end APOs when compared to the views through high end Dobs of similar money at star parties here.  We are generally pretty far south of the jet stream, though.

I don't know why, but it is strange for me to compare same price but different apertures. If I want to compare, I will compare 8 inch SCT vs 8 inch newt vs 8 inch APO, more apples to apples. Even so, there will be a big difference in quality between them, made on order vs Chinese mass production.

So it's more like home grown apples vs supermarket apples. All apples but different flavors 🤣