CCD cameras have challenged telescope optics beyond anything ever placed
at the focal plane. I knew our APO objectives were up to the challenge, and with
the proper tweaks would be extraordinary tools for the imager. With Tele Vue
Imaging System (is) telescopes, we have refined our instruments and
optical equipment beyond anything a CCD chip has seen. ...We were encouraged to
further develop is telescopes and accessories to maximize aperture, real
field coverage and performance, and make the processes easier for the imager.
-Al Nagler



We were determined to make the NP series optically, mechanically and
functionally as perfect as possible for imaging up to 50mm diagonal chips
without penalty to its near ideal visual operation. How? By applying the
developments created for the Tele Vue 60is to the new NP101is and
then going beyond.



The NP101 (101mm aperture, 540mm f.l., f/5.4) maintains its optical
specifications with redesigned 4-element optical systems. Larger rear lens
groups absolutely minimize vignetting in formats up to 50mm diagonal. For these
large chips an optional field corrector was developed so the corners of the
newly brightened edges would virtually be as perfect as the center of the field.



In order to take full advantage of the larger lenses, a non-vignetting focuser
was developed to prevent any restriction of the larger converging light cone.
The draw tube has a 3-inch front aperture and 2.4-inch rear aperture. This new
drawtube also permits quick change from visual to imaging operation and allows
full camera rotation without focus change. In addition, it has the capability to
correct for any residual focal plane tilt and accepts a position stop for our
digital micrometer to allow repeatable focus measurement to 0.0001 inches.



To maintain squareness to the optical axis while changing camera orientation,
the draw tube has four lock screws that tighten against a taper on the imaging
insert ring. The insert is threaded to accept the new Tele Vue new Imaging
System accessories including large diameter extension tubes, optical
accessories, and camera and CCD attachments, all with mating threads.



The FocusMate 6:1 planetary ball type reduction focuser is supplied standard and
provides extremely sensitive focus adjustment, measurable with the optional
Digital Micrometer Kit to better than 1/10000 of a inch. Also, the optional
FocusMate Driver permits electronic motor control of the focusing process. The
FocusMate driver has direction push-buttons and adjustable speed. A tap on the
push button permits vibration-free focusing in steps as small as approximately
0.0005 inches. The FocusMate Driver can be remotely computer controlled with
software under development.



Tele Vue has been known for producing visual instruments even better than you
imagined. We aim to achieve the same with our imaging equipment. Our
dedicated local machinists and in-house staff are as committed as ever to
delivering on these quality and performance goals.