np101和他兄弟np127的全部英文资料，规格。
np101： The new TeleVue NP101 represents our closest realization yet of the "ideal" multi-purpose/visual telescope. Its snap-to-focus and extremely sharp, flat-field are sure to take your breath away. It is also the best and toughest test platform to showcase all our new eyepiece introductions.
The successor to the Tele Vue-101 - The NP-101 (Nagler-Petzval) is more compact with the same 4-element, 540mm, f/5.4 specifications. The new scope is 4" shorter and feature both optical and mechanical enhancements over the previous model.
Features:
Telescope type: 4-element apochromat refractor using special dispersion glasses
Clear aperture: 101mm (4 inches)
Focal length: 540mm (21.3 inches)
Focal ratio: f/5.4
Resolution (visual): 1.1 arc-sec (Dawes limit for a 4" aperture)
Resolution (photo): 260 line pairs per mm
Field (35mm film): 2.5 degrees by 3.8 degrees (4.5 degrees diagonal)
Image scale: 2.7 degrees per inch
Magnification: 10x to over 250x using Tele Vue eyepieces and Barlows
Star diagonal: 2 inch, "everbrite" mirror type, with 1-1/4" inch adapter, both with brass clamp rings.
Focuser: 2 inch, rack and pinion type with brass clamp ring.
Mounting: Adjustable mounting ring with 1/4-20 tapped holes for standard (heavy-duty) photographic tripods or optional Tele Vue mounting systems
Weight: 10 lbs. O.T.A.
Length: 29", 26" O.T.A.
Accessories: Included as standard: custom-fitted case, screw-on lens cover, sliding dew/glare shield, 2" everbrite, 1 1/4" adapter.
Tube color: Ivory color powder-coated aluminum tube, black anodized lens housing, focuser assembly and mounting ring.
Aperture gain: 208 (compared to a 7mm exit pupil)
Dew Shield: Captive/Sliding, with Moisture Absorbent Lining
Mount Ring: Captive/Sliding with (3) ?20 attachment holes and 2 accessory slots.
Case: Custom Hard Shell std. Soft airline carrying bag as optional accessory.
np127：Custom NP-127 Hardshell Carrying Case featuring accessory storage in the lid and hand notches for a sure grip when lifting the scope. Case is the same size as the TeleVue NP-101 / -102.
Accessory storage area in hardshell case houses the standard 2" Everbrite star diagonal and 1-1/4" reducing adapter, plus three 1.25" eyepieces.
TeleVue is excited to bring a regular production telescope larger then 4" to market. TeleVue has been working on the NP127 for longer then you can imagine and they feel it is finally where TeleVue wants it both optically and mechanically. The NP127 certainly faces some stiff competition. However, TeleVue believes there is not another instrument that combines its fast f/5.2 focal ratio, 4 degree field and delivers all of TeleVue's acknowledged benefits. For the most discriminating refractor aficionado the NP127 is on the leading edge of apochromatic refractor technology.
Features:
OTA with sliding, captive dew shield
Included tube rings
Includes 2" Everbrite Star Diagonal and 2" - 1.25" reducing adapter
Includes custom fitted hardshell carrying case
Clear Aperture: 127mm (5")
Focal Length: 660mm
Focal Ratio: f/5.2
Visual Resolution 0.9 arc-sec.
Weight: 14 lbs. (O.T.A.)
Length: 33" (O.T.A.) |
etzval的结构镜子，固然有很短的焦距，但是镜桶最小长度却都大于焦距，这是结构所致，Petzval的后组镜片，其实有两个最主要的功能1缩短焦距2平坦像场。就Petzval结构的前组两片物镜焦距而言，实际焦距都比较长（后组相当于0.6X的减焦距镜子），所以色散容易得到纠正，这也是NP镜子可以做到无色散的原因。
置顶卡
变色卡
千斤顶
显身卡