Re: Do you reviewed the RCX 400 ?


"Thierry" <-> wrote in message news:428b8df9$1@xxxxxxxxxxxxx
>
> "Paul Winalski" <prune@xxxxxxxxxxxxxxxxxxxx> wrote in message
> news:60vm81pra5m453849revssuibdt04jk0hg@xxxxxxxxxx
>> I think he meant that, strictly speaking, the Meade
>> RCX line of telescopes is not a true Ritchey-Cretien
>> design. A true R-C has hyperbolic primary and secondary
>> mirrors. The Meade design has a spherical primary working
>> with a corrector plate to deliver an image to the secondary
>> that is nearly identical to what the hyperbolic primary of
>
> Right sir ;-) hence my question : is the result better or not (even vs.
> a
> SCT or a MCT)
>
> Thierry
The problem is that nobody really knows, and even if they did on the
individual early examples, this would be no proof of what is going to
happen on latter production quantities of the scopes...
Basic on some guessing, and ray tracing, my expectation is that the scope
will display images similar to those on the centre field of an SCT, with a
_curved_ field, across a reasonably large area. This means it'll show a
little chromatic aberration (with a true RC does not), and the same curved
field as an SCT or RC, but like an RC, without the coma that is apparent
as you move out across the SCT field. My description was 'SCT-GT', and as
such (and given just how good some SCT images can be at the centre field),
it'll work well for a lot of imaging. If you refocus for each filter for
colour images (which will correct for the CA), results should be
approaching those from a normal RC, provided the accuracy of the optics is
good.
How well the mechanisms will really work, will unfortunately take a while
to find out, with problems only being seen once the scopes exist in
quantity, and are put through the wide range of conditions that exist in
the real world...

Best Wishes

>> a true R-C would deliver. The Meade design makes the optics
>> easier to mass-manufacture, at the expense of another piece
>> of glass in the light path.
>>
>> Meade has a clever design here, but it really shouldn't be
>> called a Ritchey-Cretien, because it's not.
>>
>> -Paul W.
>>
>> On 18 May 2005 00:36:32 -0700, "Vader" <aries@xxxxxxxxxxxxxxxxxx>
>> wrote:
>>
>> >Hi Chuk,
>> >
>> >I didn't understood what you did you reaaly meant.
>> >
>> >Valery


.

Relevant Pages

  • Re: Do you reviewed the RCX 400 ?
    ... I think he meant that, strictly speaking, the Meade ... RCX line of telescopes is not a true Ritchey-Cretien ... A true R-C has hyperbolic primary and secondary ... The Meade design has a spherical primary working ...
    (sci.astro.amateur)
  • Re: Rules of Evidence (S&T January Editorial)
    ... Meade could have called this telescope an "optimized SCT," an "aplantic ... I agree it is all about marketing. ... trademarl of the design itself is in having that specific feature. ...
    (sci.astro.amateur)
  • Re: Rules of Evidence (S&T January Editorial)
    ... Meade could have called this telescope an "optimized SCT," an "aplantic ... I agree it is all about marketing. ... trademarl of the design itself is in having that specific feature. ...
    (sci.astro.amateur)
  • Re: Rules of Evidence (S&T January Editorial)
    ... Azari's apparent lies to the Court about being misled by the Meade ... The 4-element Plossl eyepiece design has over decades built up a well- ... "Super-Plossl", so that you piggyback on the reputation that the real ...
    (sci.astro.amateur)
  • Re: New Meade Series 5000 Eyepieces - Taking a run at Televue
    ... > eyepiece game. ... I notice that Meade has gone back to the 5-element ... This is a Masuyama design (i.e. Takahashi LE ... advantage vs typical "plossls". ...
    (sci.astro.amateur)