Eyepiece or focal reducer

[oscar_camilleri]

Hi all

I have an 8 inch sct. I'm trying to get the pleiades in the whole field of view. Was wondering which would be the best way to go about it? Get a wide field eyepiece like a 32 or 40 with an 85% fov or get a reducer. Or combination of both?

[Louis D]

I don't think it's possible with the maximum field of view of an 8" SCT being about 1.4 degrees and the Pleiades being about 1.8 degrees.  Even in an 8" Dob with a 1200mm FL, it's a bit of a tight fit.

You can't combine an F/R with a 2" diagonal and widest field 2" eyepieces without severe vignetting.

The cheapest route is generally the F/R if you've already got a 32mm Plossl or 24mm SWA eyepiece.

[KP82]

The cheaper way is to pick up a ST80 and use it with your existing eyepieces.

Edited April 9, 2021 by KP82

[oscar_camilleri]

Thanks for the input. Will invest in an F/r and see how that goes. 

[John]

A F/6.3 focal reducer used with the widest field 1.25" eyepiece will give you a true field of about 1.3 degrees I think. Not enough to fit the whole of the Pleiades in, unfortunately.