EQUIPMENT
THE PRIMARY INSTRUMENT in use at Land of Oz Observatory is an Astro-Tech AT-92 92mm aperture f/5.5 Apochromatic Triplet Refractor of 506mm focal length, used in conjunction with a Stellarvue SFFX1 field flattener and a ZWO ASI 2600MC CMOS digital imaging camera. This camera has a SONY IMX571 back-lit 23.6 X 15.6mm sensor with 3.76 micron pixels (26 megapixels). At the AT-92s native focal length of 506 millimeters, this results in a resolution of 1.53 arc seconds per pixel and a field of view of 2.6 X 1.5 desgrees. The instrument is carried on an iOptron CEM-70 center balanced GEM mount.
A RECENT IMPROVEMENT OF THE IMAGING SETUP USED AT LAND OF OZ
The photo at the left show the most recent improvement in the imaging system used at Land of Oz Observatory. Shown is the new ZWO EAF electric automatic focuser mounted on the AT-92 92mm APO Refractor.
This new electric automatic focuser has allowed us to consistently focust stars to an HFR reading of 3.6 or lower, all at the click of a mouse button!
FIRST LIGHT at the new LAND OF OZ observatory.
On June 22, 2025, the first astro image was captured at my new location in Lee's Summit, MO. Shown at right is the Astro-Tech AT-92 refractor mounted on the iOptron CEM-70 mount, with the Stellarvue 50mm Guide Scope. The first image was a 90 minute integration of 90 second exposures of M-27, the Dumbbell Nebula.
Here is a close crop of the "first light" mage. The full frame is
2.5 by 1.6 degrees, and the target looks small. This is a crop to zoom in on M-27. This image is a 90 minute integration of 90 second exposures through the Astro-Tech AT-92 92mm APO triplet refractor, using the 2600MC Pro camera, cooled to 0 degrees. Acquired in N.I.N.A, guided by PHD2, Processed in PixInsight and Photoshop.
This is a view of the N.I.N.A. imaging screen during the recent capture of an image of M-13. As can be seen from the guiding graph below the image,
the guiding during this session was very good, averaging about 1.15 arc seconds. The resolution of this scope/camera
combination is 1.53 arc seconds
per pixel. Also note that the HFR value is 4.47.
