C-FOCAL,1969

01.10 T "PROGRAM FOR DEPTH OF FIELD FOR STILL CAMERA LENSES."!!
01.20 A "WHAT IS YOUR LENS' FOCAL LENGTH?(IN INCHES)"  L
01.30 S CC=L/1000
01.40 A "WHAT IS THE CAMERA-TO-SUBJECT DISTANCE (IN FEET)?" DL
01.45 A "WHAT IS THE F-STOP SETTING OF YOUR LENS?" M
01.50 S DL=DL*12
01.60 S DN=DL/(1+(DL*CC*M)/L^2)
01.70 S DF=DL/(1-(DL*CC*M)/L^2)
01.80 I (DF) 2.1,2.1,3.1

02.10 T "THE FAR LIMIT OF THE DEPTH OF FIELD IS INFINITY"!; G 3.2

03.10 T "THE FAR LIMIT OF THE DEPTH OF FIELD IS" DF/12, " FEET."!
03.20 T "THE NEAR LIMIT OF THE DEPTH OF FIELD IS" DN/12, " FEET."!

04.10 Q
*@h