In the construction of solar filters and associated instrumentation,
Coronado takes enormous care to optimize contrast by minimizing the
number of components and designing them so that they do not result
in creating residual reflections and spurious light near the image.
Until recently, the only component not included in this overall
approach was the eyepiece. Now the new CEMAX (Contrast Enhanced)
series eyepiece fills this need. Specifically designed for use at
H-Alpha and multi coated on every surface (including cemented
surfaces), the CEMAX eyepieces are the ultimate in contrast
enhancement for the solar observer.
Properly designed Barlows do wonderful things: They amplify power,
slow the telescope’s f/# (improving eyepiece sharpness), and give
designers the opportunity to compensate for eyepiece aberrations.
Tele Vue Barlows use multi-coated high index glasses for optimum
aberration correction, exceptional contrast with virtually no light
loss. Observed performance is aberration free, even when tested with
f/4 scopes. They even improve our competitor’s eyepieces and
telescopes!
Powermate™ vs. Barlow
To understand the Powermate, we must first understand the Barlow
lens. Barlows amplify the power of a telescope. They can be
considered ”focal reducers” for eyepieces, or ”focal extenders” for
objectives. Terence Dickenson, in his Barlow test report in Sky and
Telescope, July 1997, says: ”Technology has erased the old
objections. A modern Barlow will not degrade your telescope’s
optics. Anyone telling you otherwise is using outdated information.
Moreover, the highly regarded Nagler eyepieces and their clones have
built-in Barlows, ample evidence that the lens is not some
detrimental intruder.” Thanks, Terence, for laying the myth of the
degrading Barlow to rest.
