The dream machine for imaging is here! The NP-101 is now picture-perfect! This telescope retains the exemplary wide field and planetary visual capability of the original, but sports new features to make imaging easier and more flexible. The re-designed Televue NP101is features new optics with larger rear lenses for chips up to 50mm diagonal. Includes a larger focuser with Focusmate installed. Quick change from visible to imaging operation with new re-designed draw tube, which also allows full camera rotation without focus change. Comes with hard case and adapters to accept imaging accessories or a 2 inches diagonal (sold separately) for visual use. The Tele Vue-NP101(Nagler/Petzval) represented Televue's closest realisation yet of the ideal multi-purpose photo/visual telescope. Its snap-to-focus sharpness across even the widest true fields, and rich planetary contrast earned it a reputation as the best 4 inches APO in its class. Now the NP101is is a redisigned telescope to accomodate the needs of imaging with CCD chips up to 50mm. The original NP101 showed slight light drop towards the edge of a 35mm film plane - no longer the case with the NP101is. 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. The draw tube has a 3 inches front aperture and 2.4 inches rear aperture. This new draw tube 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 Televue's digital micrometer to allow repeatable focus measurement to 0.00254mm. 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. This insert is threaded to accept Tele Vue's 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 included as standard provides extremely sensitive focus adjustment, measurable with the optional Digital Micrometer Kit to better than 1/10,000 inches. 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 button permits vibration-free focusing in steps as small as approximately 0.0005 inch. The Focusmate Driver will be able to be remotely computer controlled with software under development. Specifications: 101mm f/5.4 Apochromatic Refractor Nagler/Petzval design incorporating full aperture doublet (front) and sub aperture doublet (rear) Focal length: 540mm Weight: 4.9kg Max visual field: 4.9 Supplied with: Custom Hardshell case, screw-on lens cover sliding dew shield, indexed 2 inches accessory adapter and imaging insert threaded for imaging system components. Ivory powdercoat finish