THE PRIMARY INSTRUMENT in use at the observatory is an 11-inch (280mm) aperture Celestron Schmidt Cassegrain telescope of 2800mm focal length (f/10 focal ratio). The C-11 Optical Tube is mounted on a Mountain Instruments MI-250 German Equatorial Mount. This mount features 7.5 inch gears with matching diamond-lapped worms on both the RA and DEC axes. Tracking accuracy is + or - 4 arc seconds. Load capacity of the mount is 75 pounds. The optical tube is attached to the mount via a Casady precision tip-in saddle. In this photo, the telescope is set up for digital imaging at f/2 using a HyperStar III corrector lens mounted in place of the normal secondary mirror. Mounted on the HyperStar lens is a ZWO ASI 071 MC CMOS digital imaging camera. This camera has a SONY IMX071 23.6 X 15.6mm sensor with 4.78 micron pixels (16.2 megapixels). When using the HyperStar imaging system this gives a 2.5 X 1.5 degree field with a resolution of 1.76 arc seconds per pixel. Also used with this system is a Starlight Express SXVR H694C Color CCD imager.
Also visible in this photo are the 80mm (3.1")
ORION guiding telescope and the 80mm (3.1") ANTARES erect-image finder scope.
The MI-250 mount is controlled remotely from the adjacent control room using THE SKY 6 software in conjunction with the GEMINI I controller shown
in the photo just below the mount.
ASTRO IMAGING EQUIPMENT
The photo to the right is a closer view of the hardward used for guided astro imaging at the observatory.
The 80mm (3.1") ORION ED 80 Apochromatic guiding refractor is mounted atop the C-11 OTA using Losmandy heavy duty dovetail base and rings. Attached to the guiding telescope is a ZWO ASI 174MM CCD guiding camera, which sends guiding corrections to the MI-250 mount via an RS-232 connection.
Also shown is the MICRO-TOUCH stepper motor
focuser, which provides precise focus adjustment. Each motor step moves the focusing
screw 1/3000th of a revolution.
During an imaging session, both the imaging camera, guiding camera, and MI-250 mount are controlled remotely from the CONTROL ROOM, via underfloor cabling, using MAXIM DL 5.2 software running on an HP 15-dh-1054 OMEN
5gHz laptop computer.
Below is a closeup of the MICRO-TOUCH stepper
motor focuser on the C-11.
Pictured below is the ZWO 174mm Mini guiding camera
THE CONTROL ROOM
Shown at right is a photo of the desk in the control room at LAND OF OZ OBSERVATORY.
To the right ofthe HP Laptop Computer is the hand pad for the MICRO-TOUCH DIGITAL FOCUSER for the C-11 and the hand pad for the JMI MOTORIZED FOCUSER for the 80mm guide scope.
Below is a photo of the laptop screen during an imaging
session. The MAXIM DL screen is open, showing the down-
loaded image, the camera control box, the histogram box, and the guiding graph, which is showing excellent guiding with very small corrections.
Setting up for an evening of imaging: The photo to the left shows the C-11 telescope on the MI-250 equatorial mount with the HyperStar imaging system and the Starlight Express SXVR-H694C color CCD imager mounted. Also shown is the 80mm f/7.5 guiding telescope. This photo taken by Dave Hudgins in July of 2018.