User manual SBIG STV

[. . . ] PRICE $10. 00 Operating Manual STV Video Camera and Autoguider Santa Barbara Instrument Group 147-A Castilian Drive Santa Barbara, CA 93117 Phone (805) 571-7244 Fax (805) 571-1147 sbig@sbig. com www. sbig. com Santa Barbara Instrument Group 147-A Castilian Drive Santa Barbara, CA 93117 PHONE (805) 571-7244 FAX (805) 571-1147 Note: This equipment has been tested and found to comply with the limits for a Class B digital device pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. [. . . ] When the best exposure time is calculated, the STV will capture an image and select the brightest star in the frame. A shrinking box will briefly highlight the selected star. At the fast rate, the star's centroid is determined every 200 milliseconds. The fast rate is best for measuring high frequency drive or mount vibrations. At the slow rate the star's centroid is determined every 2 seconds. The slow rate is best for measuring the drive's periodic error. The video screen will show a graph similar to the screen shot below: DRIVE MONITOR TIPS When the guide star is selected the STV assigns a brightness value to the star. If the brightness falls to a low level the message "Dim" will appear on the top line of the alphanumeric display in place of the Exposure time. If the star saturates the CCD, the message "Bright" will appear. If the guide star is lost or moves too close to the edge of the CCD, the message "Off CCD" will appear. See Appendix C, page 50, for details. The alphanumeric display will report the following information: DRIVE (fast) Exp=50ms RMS xy= 2. 1, 1. 9 arcsec The graph shows the position of the star with time. In fast mode the STV reports the exposure time and the RMS (root mean square) variation in X and Y over the last 16 points. In slow mode the STV reports the peak to peak variation since you began the measurement. For a more explanation of the theory and calculations behind the Drive Accuracy Monitor mode see Appendix C, page 50. 24 Seeing (DIMM) The Seeing Monitor mode uses a Differential Image Motion Monitor (DIMM) technique to measure your seeing conditions independent of your system's optical quality and drive errors. In order to use the Seeing Monitor mode you must make a two-hole aperture mask for your telescope and follow the other special instructions found in Appendix C, page 51. When you have properly set up your telescope for this measurement, select the Seeing Monitor mode. The display will show: MONITOR SETUP SEEING (DIMM) Do It! Enter the seeing monitor mode by hitting the Value button. The software will automatically find the stars, adjust the exposure, and start collecting data. It can be quite impressive seeing how the two images move relative to each other!A graph will appear on the video screen similar to the following: SEEING MONITOR TIPS: Once the graph of the error vs. time is on the video screen you can toggle on the three dimensional stellar profile graph by hitting the Value button. When the 3-D graph is active the video update rate is slowed. [. . . ] If using Track and Accumulate you are probably using a snapshot time that is too long. If the snapshot time is longer than the amount of time your drive can track unguided with acceptable guiding errors, you will see elongated stars in your final images. If your snapshot times are getting down to 30 seconds or less you should improve your drive. If you are using your camera as an autoguider for film photography and are noticing unacceptable guiding errors, please check the following: 1. [. . . ]