What kind of camera is the 2.1mm CS lens compatible with?
This lens is designed for cameras that use the CS-mount standard. This includes many dedicated all-sky cameras, security and surveillance cameras, and some specific astronomical guide cameras. It is not compatible with C-mount cameras without an adapter, nor will it work with DSLR or mirrorless cameras.
Why does the 2.1mm CS lens have two different fields of view listed?
The field of view depends entirely on the size of the camera sensor you pair it with. The lens projects a circular image; a smaller sensor captures a smaller portion of that circle, while a larger sensor captures more of it.
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On a 1/3" sensor: The field of view is 150°.
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On a 1/2" sensor: The field of view increases to 190°.
Can I use the 2.1mm CS lens to build a meteor camera?
Yes, this is an ideal application. For maximum sky coverage to capture meteor showers like the Perseids or Geminids, you should pair the 2.1mm lens with a 1/2" sensor camera. This combination achieves the 190° field of view, ensuring you can monitor the largest possible patch of sky all night.
Is the 2.1mm CS lens suitable for use as a wide-field guider?
While technically possible, it is not recommended for precise guiding. The extremely short 2.1mm focal length results in a very low image scale (many arcseconds per pixel), making it difficult for guiding software to detect the small star movements needed for accurate corrections on a long focal length telescope. It is designed for imaging the entire sky, not for high-magnification guiding.
Does this 2.1mm CS lens have adjustable focus or aperture?
Lenses of this type are typically fixed-aperture and are focused by adjusting the lens's distance to the sensor by threading it in or out of the camera's CS-mount. Once focus is achieved for infinity, it is often locked in place for dedicated applications like all-sky monitoring.
Will the 2.1mm CS lens show the entire Milky Way?
Yes, when used with a 1/2" sensor to achieve the 190° field of view, this lens can easily capture the entire visible arch of the Milky Way in a single shot, from one horizon to the other. This makes it excellent for dramatic, wide-field astrophotography and time-lapses.
