Re: [William-Optics] Follow up to field flattener posts
- have you tried different eyepieces? That sounds like
it might be the problem.
--- langejcarl <langejcarl@...> wrote:
> I have a Megrez 80 II ED. When my pupil is perfectly__________________________________
> centered in the
> eyepiece all stars look perfect. If I move my eye
> around in the
> eyepiece the stars begin to get elongated and the
> direction in which
> they elongate moves as I move my eye. First, what
> causes that and does
> it have a name? Secondly, is that the situation that
> is addressed by a
> field flattener?
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- "If I move my eye around in the eyepiece the stars begin to get
elongated and the direction in which they elongate moves as I move my
I wear glasses to correct astigmatism, but I take them off when I
observe. What you are describing is exactly what I see with longer
focal length eyepieces. I had a 32mm Televue Plossl that was virtually
unusable, for me, with an F6 scope. With my glasses, I could get pin-
point stars, but without them, the stars would elongate in the
direction I moved my eye.
For me, I find this issue goes away with an eyepiece that provides an
exit pupil of 3mm or less. I have a 19mm Panoptic that is sharp all
the way to the edge.