Download Izmccd (~2.7 MB). ... a) a choice of the best mode of measurements of stars and objects ("Properties/Measurement"), . b) a choice of reference stars. ... 1) necessity of presence on an image of a plenty of stars (we recommend to apply this mode, if on the frame of reference stars is more 100) . ... Sx and Sy depend from residuals at all reference stars (reference stars are marked by blue color). ... These residuals are the image of the star a minus function of a profile for each pixel. ...