Prism Diagonal Anti Chromatic Aberration Effect?

That's true, Alan, from what I've seen in other's refractors....
somehow the refractor does seem to benefit from a slightly sharper
(and perhaps a tad more contrast) pin-points than our
'mack truck' reflectors of much larger size....but I wonder
if a larger refractor...say a 20 or 30 inch glass, would
still hold those sharp pin-points for stars?
I really don't know, never having had the priviledge of looking
thru one.
But have to admit, you are correct. (But I could have never afforded
a 30 inch portable refractor.....even if they made them!)
Clear Skies,
Tom W.




Alan W. Craft wrote:
On 15 Jul 2003 12:57:26 GMT, (Jon Isaacs) ...reflected:


Just wondering if we, who use Newtonian reflector telescopes, are
somehow missing something.
Clear Skies,
Tom W

False color???


Razor-sharpness and contrast second to none?

...precisely.

Alan

The term for the above change of focal points for different
wavelengths is called Spherochromatism, right

It's called primary color error.

Roland Christen

Razor-sharpness and contrast second to none?

...precisely.

Alan

Actually a newtonian normally does provide both "razor sharpness" and contrast.
What is missing most often with a refractor is aperture. Aperture provides
detail. It also provides contrast, though the brightness may mask brightness.


jon

On 16 Jul 2003 10:54:01 GMT, (Jon Isaacs) ...reflected:

Razor-sharpness and contrast second to none?

...precisely.

Alan

Actually a newtonian normally does provide both "razor sharpness" and contrast.

I certainly hope so, as I'm planning on buying one.

I'm tempted to try the 10" Parks 'Nitelight' on a Vixen GP-DX mount,
though that might be pushing the mount just a tad.

What is missing most often with a refractor is aperture. Aperture provides
detail. It also provides contrast, though the brightness may mask brightness.


jon

Alan