Recently I received a unique Hikvision HV0733D-6MP lens for testing. It is designed for security cameras with CS mount. The main feature is F number (F0.95) over the entire focal length range (7-33 mm), as well as support for a 1 \ 1.8 “sensor and a resolution of 6 Mp. Of course, you can use sensors with a smaller size and resolution. With excellent F number it is desirable that the matrix was back-illuminated. It feels like the lens was specially designed to work with the Sony IMX178 CMOS sensor. What could be such an interesting lens for astrophotography? Of course, this is a shooting of meteors in real time. When using 1\1.8 ” matrix and focal at a distance of 7 mm, the field of view of the lens is 51×35 degrees (60 degrees diagonal). Also, with such aperture, shooting of extended nebulae with narrow-band filters looks very tempting, but the filter will have to be installed in front of the lens. Testing will show how good this lens is by the stars.
The lens itself is atypically large and heavy for a CS lens. Lens weight – almost half a kilo (478 grams). Metal body. The diameter of the front lens is 62 mm. IR correction is not declared. On the case there are two rings with locking knobs – to adjust the focal length and focus. Everything runs smoothly and without jams. In the middle of the lens protrudes a diaphragm control unit with a cable.
Focusing and zooming are internal; the lens does not change dimensions when these parameters change. When focusing on infinity, the rear lens unit protrudes slightly, while focusing near it, it slightly goes inside.
The lens has a feature – by default, the diaphragm is closed. In order to open the aperture, you must connect the lens to the security camera with the appropriate connector. Since there is no connector for controlling the diaphragm on astronomical cameras, we need an appropriate “opener” – a separate camera powered by 12 V.
The QHY5III178m camera (1\1.8 “, 8.92 mm diagonal, 2.4 micron pixel) was used to test the lens across the sky. The lens was attached to the Sky-Watcher Adventurer mount. Location: central part of Anapa, the backyard. The Moon is 75% phase.
Test with 7 mm FL:
Full size – at link.
Test with 33 mm FL:
Full size – link.
The test results. With a monochrome camera, the lens makes a very high-quality image for its parameters. The field is flat. There are aberrations, but they are noticeable closer to the edge of the field of view. Spherical aberration is moderate. Vignetting is noticeable only in the corners. The nearest Computar 8 mm F0.8 and Computar 4.5-12.5 mm 1: 1.2 lenses showed much worse image quality across the field.
Hikvision HV0733D-6MP – perhaps this is a kind of “king” of CCTV lenses. An excellent choice for lovers of shooting meteors and unidentified flying objects in real time – in half an hour of testing, 10 satellites flew in sight. Also, this lens may be of interest to owners of mirrorless cameras with a small matrix – for example, Pentax Q7 or Pentax Q-S1.
The disadvantages of the lens carry the high cost and the need to use the “opener”.