Where:

I1	=	Intensity 1 at D1
I2	=	Intensity 2 at D2
D1	=	Distance 1 from source
D2	=	Distance 2 from source

more information:
Inverse Square Law
Calculation

Where:

E1	=	Exposure at D1
E2	=	Exposure at D2
D1	=	Distance 1 from source
D2	=	Distance 2 from source

more information:
Exposure-Distance Calculation

Where:

C1	=	Current 1
C2	=	Current  2
T1	=	Time 1 at C1
T2	=	Time 2 at C2

more information:
Current-Time Reciprocity Calculation

Film Density - Exposure

Geometric Unsharpness

      
Note: This is an approximation and is only valid for the straight line portion of the film characteristic curve.  See more info section.
Where:

E1	=	Exposure 1
E2	=	Exposure 2
FD1	=	Film Density at Exposure 1
FD2	=	Film Density with Exposure 2

more information:
Film Density - Exposure Calculation

    

Where:

M	=	Magnification
a	=	Distance from source to object
b	=	Distance from object to detector

more information:
Geometric Magnification Calculation

Where:

Ug	=	Geometric unsharpness
f	=	Focal spot size
a	=	Distance from source to object
b	=	Distance from object to detector

more information:
Geometric Unsharpness Calculation

Attenuation

Half-Value Layer

      
Where:

D	=	Defect depth from the film side of the part
t	=	Thickness of material
SD	=	Shift of defect image on the film
SM	=	Shift of surface marker on the film

more information:
Indication Depth Calculation

Where:

Ix	=	transmitted intensity
Io	=	Original intensity
m	=	Linear attenuation coefficient
x	=	Distance in material or material thickness

more information:
Attenuation Calculation

Where:

HVL	=	Half-value layer
m	=	Linear attenuation coefficient

 

more information:
Half-Value Layer Calculation