ED80 fully illuminated image size?

[JamesF]

My search skills have failed.  Perhaps I'm just too tired this evening.  Does anyone have any information on the size of the fully illuminated image circle of a Skywatcher ED80?

Thanks,
James

[vlaiv]

Have no idea but my bet is on APS-C size...

[pete_l]

I use my ED80 with the 0.85 reducer corrector and an 1100D DSLR.

So the reduced image size is 22x15mm. That gives a diagonal of 26.7mm. So the unreduced, image circle is at least 31.4mm

HTH

Edited September 19, 2020 by pete_l

[Merlin66]

James,

I think it will depend on the effective open aperture close to the image plane.

Baffles, focuser size, filter size can all cause vignetting and reduce the fully illuminated circle.

[JamesF]

On 19/09/2020 at 04:27, pete_l said:

I use my ED80 with the 0.85 reducer corrector and an 1100D DSLR.

So the reduced image size is 22x15mm. That gives a diagonal of 26.7mm. So the unreduced, image circle is at least 31.4mm

HTH

That's useful empirical evidence to work from, Pete.  Thank you.  I guess I should have thought of playing with a DSLR to see what happens myself :)

James