美国750mm望远镜

2014-08-01|来自：梦溪|发布：望远镜

美国PLANEWAVE公司由原MEADE公司员工成立，有效的解决了MEADE公司不制造大口径望远镜的瓶颈。作为有效的补充，PLANEWAVE公司制造的大口径（750mm）望远镜系统尤其适合应用于科研型场合，同时适用于科普天文台、科技馆、大学天文系等机构。

CDK系列望远镜采用独特的光学设计，CDK的设计的轴外性能远远超过绝大多数商业望远镜包括RC设计。对于当今最高级的适合业余爱好者的CCD相机，在35mm口径CCD成像面板的边缘，RMS光斑尺寸仍然小于一个像素。

Features and Specifications

System

Aperture 20 (.51m)

Focal Length 3454 mm

Focal ratio f/6.8

Central Obstruction 39%

Back Focus 8.9 from focuser mounting surface, 5.81 from racked in focuser

Weight 135 lbs

OTA Length 47

Upper Cage Carbon Fiber Truss

Lower Cage Carbon Fiber Truss with Carbon Fiber light shroud

Performance Optical Performance - Vignetting and Spot Performance

Dimensions Overall Dimensions

Primary Mirror

Diameter 20.5

Aperture 20

Focal ratio f/3

Mounting Laser Collimated and Permanently Fixed

Material Precision Annealed Pyrex

Shape Prolate Ellipsoid

Coating Enhanced Aluminum - 96%

Secondary Mirror

Diameter 7.5

Material Precision Annealed Pyrex

Shape Spherical

Coating Enhanced Aluminum - 96%

Lens Group

Diameter 90mm

Number of lenses 2

Coating Broadband AR Coatings (less than .5% from 400 to 700nm)

Standard Features

Dual Carbon Fiber Truss Design Minimizes thermal expansion which causes focus shift with changes in temperature

Carbon Fiber Lower Light Shroud Protects the primary mirror from damage and from stray light

Dovetail expansion joint Allows for the difference in thermal expansion between carbon fiber and aluminum. The expansion joint allows the aluminum dovetail expand and contract without stressing the carbon fiber lower truss

Dovetail The CDK20 comes with one of two dovetail designs. The first is the massiveand the second is a dovetail compatible with Software Bisques Versa Plate, Both utilize the expansion joint listed above.

3.5” Hedrick Focuser Heavy duty no-slip focuser. The focus tube runs on 5 bearings and is driven by a leadscrew so there is no chance of slipping. It accepts an optional dial indicator and PlaneWave’s EFA Kit to control many electronic accessories.

Cooling Fans Three fans blow filtered air onto the back of the primary mirror to help it quickly equibrate to the ambient temperature. The fans are controlled by a switch on the optical tube or can be controlled by a computer if the optional EFA Kit is purchased.

相关标签：大口径望远镜、750mm、低成本

与 美国750mm望远镜 相关的内容

Aperture	20 (.51m)
Focal Length	3454 mm
Focal ratio	f/6.8
Central Obstruction	39%
Back Focus	8.9 from focuser mounting surface, 5.81 from racked in focuser
Weight	135 lbs
OTA Length	47
Upper Cage	Carbon Fiber Truss
Lower Cage	Carbon Fiber Truss with Carbon Fiber light shroud
Performance	Optical Performance - Vignetting and Spot Performance
Dimensions	Overall Dimensions

Diameter	20.5
Aperture	20
Focal ratio	f/3
Mounting	Laser Collimated and Permanently Fixed
Material	Precision Annealed Pyrex
Shape	Prolate Ellipsoid
Coating	Enhanced Aluminum - 96%

Diameter	90mm
Number of lenses	2
Coating	Broadband AR Coatings (less than .5% from 400 to 700nm)

Dual Carbon Fiber Truss Design	Minimizes thermal expansion which causes focus shift with changes in temperature
Carbon Fiber Lower Light Shroud	Protects the primary mirror from damage and from stray light
Dovetail expansion joint	Allows for the difference in thermal expansion between carbon fiber and aluminum. The expansion joint allows the aluminum dovetail expand and contract without stressing the carbon fiber lower truss
Dovetail	The CDK20 comes with one of two dovetail designs. The first is the massiveand the second is a dovetail compatible with Software Bisques Versa Plate, Both utilize the expansion joint listed above.
3.5” Hedrick Focuser	Heavy duty no-slip focuser. The focus tube runs on 5 bearings and is driven by a leadscrew so there is no chance of slipping. It accepts an optional dial indicator and PlaneWave’s EFA Kit to control many electronic accessories.
Cooling Fans	Three fans blow filtered air onto the back of the primary mirror to help it quickly equibrate to the ambient temperature. The fans are controlled by a switch on the optical tube or can be controlled by a computer if the optional EFA Kit is purchased.