depth GEOMETRICAL E 
d of ; : 
the fiel 
ofe jantes b 
tete produeted by 
he P 
safety razor, 
ere lat, the ind 
> c 
the the object. T 
this s 
(this graphic plate 
| rudd DEYN 
\ ER, Aye E. \ 
hero, t is = 
the incident 
  
ecause 
esp ir 
           
     
    
   
      
   
   
   
  
  
    
  
   
      
     
     
    
XAMINATION ABOUT OPTICAL PROBLEM. 
The magnitude of an object in this method depends on the angle of 
d of the camera lens, and that depends on the slit-width 
cutting a metal film evaporated on the glass plate with a 
the thickness of the glass plate tn». In addition to 
his glass plate is slidden before the face of the photo- 
. lf the rays from eamera lens incident at-the points 
x,, 0 ) and after they are refracted the rays are focussed 
P'(x , y) as shown in Fig.15, we have the next relation 
= tan ji. tan r - tan iptan n, 
S m — 2 : U 
tan i»- tam i, 
  
  
; 
(2) 
tan 5 — Lan ra 
V = VV =f = = (1 = lL | 
Yo = 4Y ( tan ji, - tan is 
he thickness of the glass plate. Now if we.assume that 
angle and the refracted angle are small, we obtain the 
tan i =. , tàn r er. 
/ ] 
x50 reid BBA JL Bh 
u ; 
/ 
0 Q0) (3,0) x 
   
  
  
in Fig