nytecam wrote:

It works at f/10 and looks like a regular LX200 so is it more than a
wide-field RC corrector plate? Intregued! See
www.telescopehouse.co.uk/

Nytecam 51N 0.1W



There has been considerable discussion about these new scopes amongst
various groups to which I belong, I have attempted to distil the
collected wisdom from these discussions below.

Calling these (and the RCX line) Ritchey Chretien designs is a marketing
ploy by Meade; by definition a catadioptric scope cannot be an RC. In
fact the design is an optimised SCT and as such is to be welcomed since
it offers improved performance (compared to an SCT) at an affordable
price. A true RC design remains expensive to realise due to the
requirement to create 2 hyperboloid mirrors to a high accuracy.

All of the Meade LX200R and RCX scopes appear to employ a spherical
primary, an aplanatic secondary and a thick corrector plate. The optics
seem to be a modification of one of the optical designs investigated by
Sigler in the 1970s. To execute the new design the optician makes the
secondary a prolate ellipsoid by removing a couple of waves of glass
from a spherical secondary, and then slightly changes the figure of the
corrector plate from the standard SCT prescription. So while they are
not an RC optical configuration, they are an advance on SCT optics. The
resultant optical design has optical correction somewhat similar to a
true RC scope, i.e. elimination of coma, but does have considerable
chromatic aberration, introduced by the corrector plate, and the
curvature of field associated with the standard SCT design remains.

So, whatever you call them, they are a significant improvement over the
standard SCT: the RCX scope are f 8 versions of this design whilst the
new scopes are f 10 versions of the same design. The new scopes have
the "pseudo RC" optics in the standard GPS tubes and are available in
fork mounted and OTA only versions.

Regards
--
Derrick Farley
http://www.lh-dome.demon.co.uk/