Introduction and Overview:
SBIG’s new All-Sky camera, the AllSky-340, is SBIG’s
third version of a weatherproof AllSky camera for monitoring
weather conditions. The first had to be obsoleted when we stopped
production of the ST-237A, and the second went obsolete when the
lens we were using became unavailable, with no suitable replacement.
The third version is our best one yet! The sensor is the Kodak KAI-
340 CCD, with 640x480 pixels, 7.4 microns square, and a high gain
output stage for excellent sensitivity. The camera containing the
CCD is our SG-4 Smart Guider camera, our new autonomous guide
camera that is also available.
The All Sky 340 camera, illustrated below in Figure One,
incorporates the SG-4 Camera inside an aluminum enclosure with an
acrylic dome to protect the fisheye lens. The fisheye lens
recommended by SBIG is Fujinon’s new FE185C046HA-1, with a
1.4 mm focal length, F/1.4.
Figure One: All Sky 340 Camera
2
The image quality is excellent wide open, all the way to the horizon.
Figure Two shows an All Sky camera image with the Fujinon lens
and KAI-340 CCD. The exposure was 60 seconds from a light
polluted backyard – the first quarter moon had just set behind the
