The ZWO LENS-2.8-12 with a 2.8-12 mm variable focal length and f/1.4 aperture is designed for CS-mount cameras such as the ASI120MM/MC , ASI290MM/MC and ASI224MC . With a larger effective diameter than the 2.1 mm lens that comes standard with some ZWO models, it provides a wider field of view and higher light efficiency. It is often used for photographing meteors and the night sky, especially in combination with sensitive monochrome cameras.

The lens has a metal body, a CS mount (also compatible with C after using a spacer adapter) and the ability to adjust the focal length in the range of 2.8–12 mm. At a focal length of 2.8 mm, it offers a very wide angle of view (about 100°).

Technical parameters

• focal length: 2.8–12 mm
• aperture: f/1.4
• mount: CS (compatible with C using an adapter)
• Active diameter larger than in the 2.1 mm ZWO lens
• total length: 41 mm
• Maximum diameter (body): 31 mm
• weight: 56 g

Question : What is C-mount?

Answer: C-mount is a thread found in industrial camera lenses and connectors, an external thread with a diameter of 1 inch (25.4 mm) and 32 threads per inch. This internal thread is found in industrial cameras and some adapters for astronomical cameras (Imaging Source, ZWO ASI, etc.). The CS mount differs from the C mount only in the distance from the sensor, it has the same thread.