[ATM] Barlow quality/testing

["tony gondola" <acgna@comcast.net>]

Does anyone have any insight into the overall quality and general aberrations of typical barlow lenses? As an avid lunar imager the barlow is a critical link in the imaging chain and I'm not convinced at this point that most of what's commercially available is really the best answer. I'm especially gun shy when a manufacturer claims to reduce aberrations when used with certain ocular designs. For CCD work that last thing you'd want is a barlow that's introducing aberrations of an a sign opposite that of the typical ocular in an effort to obtain better visual performance. What the imager needs is a pure barlow with good color correction and no introduction of spherical aberration. I've star tested several and none so far can really meet that standard. Any thoughts out there on this? I hate the idea of sweating blood to make a great planetary mirror only to be undone by the barlow.

Tony
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