Colour error or atmospheric dispersion?

I don't know if this will link,
but this shot of the Moon
taken with a 92mm fluorite triplet at
3500mm seems to show noticeable
chromatic aberration.

http://tinyurl.com/3rua8

Tom Davis, who owns the 92mm Burgess Fluorite refracter reported that
there was no in focus color and only faint traces inside/outside of
focus during various star tests. This is typical of a fluorite doublet.
He took several images with different settings and equipment. There was
some color when a focal reducer (designed for a SCT, IRRC) was used. If
you posted links to the other shots, you would see another lunar image
without color. In addition, this is a visual scope, so the color
correction may not match the CCD sensitivity. Go to the Yahoo Burgess
group, follow the thread and images and you'll see that this is a nice
scope.

Jim Johnson

On 8 Dec 2004 11:38:14 -0800, wrote:

Tom Davis, who owns the 92mm Burgess Fluorite refracter reported that
there was no in focus color and only faint traces inside/outside of
focus during various star tests. This is typical of a fluorite doublet.
He took several images with different settings and equipment. There was
some color when a focal reducer (designed for a SCT, IRRC) was used. If
you posted links to the other shots, you would see another lunar image
without color. In addition, this is a visual scope, so the color
correction may not match the CCD sensitivity. Go to the Yahoo Burgess
group, follow the thread and images and you'll see that this is a nice
scope.

Jim Johnson

I'm sure it is. I figured it might have been the eyepiece they
used for the projection, since eyepiece projection (as it exists
now) does not mix too well with digital cameras yet.
-Rich