Blur circle

[ric YAMA]

What is the relationship between blur circle, depth of field, and image magnification. Could everybody explain briefly? (I 've just started 8 x 10 and like to make really huge prints bigger than 20 x 24in.)

[pat j. krentz]

What you are calling blur circle is known as the circle of confusion, depth of field is that portion of the subject is in sharp focus, which vary's with the apeture used and the distance focused on, and if you are talking about image magnification in the camera you are talking about conjugate foci. The best book you will find for understanding these terms and concepts is: Photographer's Mate 2&3 by the Bureau of Naval Personal, Rate Training Manual NAVPERS 10355-A. When you finish reading the section on photographic optics you will begin to have an understanding of what is involved in the terms you mentioned. Good Luck. Pat