Imaging circle question

[Anthonyexmouth]

does a larger imaging circle eliminate vignetting? Anyone know how much bigger the SW esprit 100 is compared to the ED80? Thinking the esprit is going to be my next scope and wondering what the improvements are going to be over my humble ED80. 

[vlaiv]

Although large imaging circle refers to optics correction rather than vignetting - in most cases larger imaging circle means larger unvignetted portion.

You should not concern your self with corner vignetting - it is not related only to telescope, sometimes other parts of system can introduce a bit of vignetting - like correctors and filters unless they are very large, but in any case - flat fielding solves that.

[Anthonyexmouth]

15 minutes ago, vlaiv said:

Although large imaging circle refers to optics correction rather than vignetting - in most cases larger imaging circle means larger unvignetted portion.

You should not concern your self with corner vignetting - it is not related only to telescope, sometimes other parts of system can introduce a bit of vignetting - like correctors and filters unless they are very large, but in any case - flat fielding solves that.

not that concerned but just looking at and counting the advantages to justify splashing out £1600. 

[ollypenrice]

42 minutes ago, Anthonyexmouth said:

not that concerned but just looking at and counting the advantages to justify splashing out £1600. 

Much better colour correction, particularly in blue. Smaller, tighter stars. Fascinating black hole in your bank account. What astronomer could resist such temptations?

Olly

[Anthonyexmouth]

8 minutes ago, ollypenrice said:

Much better colour correction, particularly in blue. Smaller, tighter stars. Fascinating black hole in your bank account. What astronomer could resist such temptations?

Olly

So is it a very noticeable upgrade or one of those "expert eyes" can tell the difference?

[ollypenrice]

Just now, Anthonyexmouth said:

So is it a very noticeable upgrade or one of those "expert eyes" can tell the difference?

Probably somewhat target dependent. I think your camera is colour so you won't be a narrowband specialist? It is easier for more basic optics to give a good image through NB filters because the light is almost monochromatic. In colour imaging you'll see the biggest difference with the upgrade. Images including insistent starfields will give an easily perceptible difference. For all that, the ED80 is no slouch and punches above its weight. Then again, in the Apo world, the Esprits punch above their price.

Olly

[Anthonyexmouth]

6 minutes ago, ollypenrice said:

Probably somewhat target dependent. I think your camera is colour so you won't be a narrowband specialist? It is easier for more basic optics to give a good image through NB filters because the light is almost monochromatic. In colour imaging you'll see the biggest difference with the upgrade. Images including insistent starfields will give an easily perceptible difference. For all that, the ED80 is no slouch and punches above its weight. Then again, in the Apo world, the Esprits punch above their price.

Olly

I think the thing i'm looking forward to the most is a nice focuser, my ED80 was second hand and struggled with slipping/shifting since i owned it. tried all the usual tweaks