Morris's method

Method was independently developed by Charles Morris and Stephen James O'Meara in the 1970s. This is the most common and universal method as it allows to bridge disadvantages of both Sidgwick and Bobrovnikoff methods, remaining a bit more complicated to use although. The method can be effectively used for the comets with a degree of condensation DC from 1-2 to 8.

 

The essence of the method is as follows: the observer puts comet slightly out of focus just to flatten its surface brightness, remembering therefore the brightness and the apparent diameter of the out-of-focus comet. Next, the comparison stars chosen to be as close as possible to the brightness of the comet should be defocused to the same out-of-focus diameter.

 

 The complete name of the method is Modified-Out method discussed by C. S. Morris (ICQ 2, 69). Represented by the letter "M".