This TeleVue 0.8x magnification auxiliary multicoated lens system reduces the focal length of all TeleVue Petzval-type refractors. These include the Genesis, Genesis SDF, TV-101, NP-101, NP-127, TV-140, NP-101is, and NP-127is. The reducer provides wider field imaging with APS format film cameras having a 34.5mm diagonal film size. It also works with standard 35mm film cameras, although with some vignetting of the film corners possible.
The reducer is optimized for the 55mm back focal length typical of 35mm SLR cameras that accept T-rings. To attach an optional T-ring to the back of the reducer, you will need either optional adapter #13TRA to use a standard T-ring or optional adapter #13CAW to use a Canon T-ring (the #13CAW eliminates the inner portion of Canon T-rings to provide a larger diameter opening for reduced vignetting).
For telescopes with 2" focusers (such as the NP-101, NP-127, and TV-101) you will need to attach optional adapter #1363 to the front of the reducer to connect to your scope’s 2" focuser drawtube in place of the imaging system adapter supplied with the IS scopes and indentified as part A in the system chart feature image below.
With the TeleVue NP-101is or NP-127is, you will need to connect an optional 0.50" long threaded extension tube #13T050 between the reducer and the Imaging System Adapter supplied with these scopes, as shown in the feature diagram from TeleVue shown below.
Optimum performance is obtained with the NP scope models and cameras using APS size format film (which has an approximately 34.5mm diagonal image). Standard 35mm film cameras having an approximately 44mm diagonal will also work, although there will be some vignetting of the image. In all cases, the field of view and lens speed increases by 25%. For example, with an NP-101 and a 30mm diagonal format camera, the focal length decreases from 540mm to 432mm, the focal ratio shortens from f/5.4 to f/4.3, and the field of view increases from 3.2° to 4.0° across the 30mm film diagonal.
|Name||TeleVue - 0.8x Reducer for NP Scopes|