iris out
4.Iris test instrument can help human find the headspring of illness in advance (sub-health condition).and make adjustment according to the illness condition and weed out sub-health condition at the seed state .make you always in a healthy condition ,and far away from the violation of modern illness.
5.To keep a constant luminance of the specific image object despite of a variable lighting, and therefore to enhance the performance of the video measurement & control system, an auto-adaptive control method of stepless adjustment to CCD exposure was put forward. The method was carried out by the coordination of electronic shutter and motor-driven iris diaphragm.
6.Photographic observations of the recurrent nova WZ Sge have been carried out,at Beijing Observatory, using the 40/200 cm double astrograph with the Eastman Kodak 103a O plates wi-thout filter, during the recent outburst of WZ Sge, from Dec. 6 to 25, 1978. All plates were measured by an iris photometer, and the photographic magnitudes were calibrated by the-stars in the selected area.
