Celestron versus Meade

Home Forums Spectroscopy Focal reducers for Alpy! Celestron versus Meade

Tony Rodda


Slightly confused… Given the discussion at the workshop i was left with the distinct impression that I need a focal reducer for my f10 SCT to get the best Aply match.  I have both Meade and Celestron reducers.  I’ve copied the following from an old community discussion and there appears to be a big difference in the respective focal lengths.

Which one is the best match for mating the f10 SCT to the Alpy?  Am I right in assuming the longer FL will produce less chromatic aberration? but if so what does that do to the SCT/Alpy focal length match?

“I recently measured the focal length of a Meade 0.63x and a Celestron 0.63x focal reducer – the Meade had a focal length around 145mm and the Celestron around 235mm. So the “optimal” distance between lens and focal plane is greater for the Celestron; about 50-55mm for the Meade and around 85mm for the Celestron. The focal length measurements were pretty crude (+/- 5mm?) but clearly a difference.”