Lighting Ratio's

Lighting Ratios 

Lighting ratios are the comparisons between key and fill light. The higher the contrast of the image the high the ratio and therefor the lower the contrast of the image the lower the ratio.  Different ratios are commonly used for certain things, for example:

-       1:1 ratio is commonly used for babies and small children because they make sudden movements. 

-       2:1 ratio is used for women’s portraits because it has a lower contrast and this is seen as being more flattering.    

-       Whereas a ratio of 4:1 is used for men as it is more dramatic.

Below is a table that I found which really helped me understand how lighting ratios are worked out in relation too F-Stops.  

Ratio	Exposure Difference	The result
1:1	Equal	Even or “flat” lighting
2:1	1 Stop	A nice ratio for general images…
3:1	1 1/2 Stops	This provides soft shadows on the subject – quite nice!
4:1	2 Stops	Low key and dramatic lighting of the subject
8:1	4 Stops	Very dramatic lighting and loads of contrast