How to control light spread in a volume? Quick question, is there any possibility to control the Area light somehow? I want to achieve a similar effect as you can see in the following image. Basically I need a higher contrast and would like to get the light more "sharp".



How to achieve that? Any suggestions? 



Thank you @JachymMichal! That's close, but not exactly what I meant. Because you are using a spot light, the rays are not as parallel as I'd like having them. Basically I'd like to get a pretty harsh contrast and sharp shadow without the soft transitions. Tried to visualize it here:



Any other solution?
You'll be better off with a Spot or Sun lamp.
Sharper shadows can be achieved by decreasing Volumetrics density.

Spot lamp


for straight rays decrease the spot shape Angle value
for harder shadows increase power and Blend value


Sun lamp


keeps rays perfectly straight
for harder shadows increase strength and decrease angle


Example of a Spot light with a narrow cone (8°).


Example of a sun lamp with perfectly parallel rays.