26 Apr
2010
26 Apr
'10
12:26 p.m.
Chuck wrote:
Kurt, a home-made Barlow is an easy solution to customizing EFL. You can select a negative achromat to suit your needs; you might peruse the selection at Surplus Shed.
The PST really needs 1:1 teleextender to pull that wierd focal plane out of the eyepiece holder to where a camera can get at it. But it's getting to be a moot point, since the Lunt solar telescopes are the new thing to buy and do not have that design limitation.
Perfect achromatism isn't a concern since you are imaging at a single wavelength.
Good point. I hadn't thought of that. So, what's an ethalon and how does the Lunt incorporate into a refractor design? Clear Skies - Kurt