Tuesday 24 July 2018

focal length - Keeping two subjects in focus (depth of field)


What is the best way to get two subjects in focus in a portrait (sometimes not at the same distance from the lens)? Obviously, this is a question of depth of field, but I am curious what some of the best tips are to get a sharp image with multiple subjects at different distances.


In case it helps, I'm using a D800 with a 50mm lens, typically at f/1.8 (aperture priority mode).




Answer



Best bet is to carefully understand the Depth of Field that your chosen settings will provide, and position your subjects accordingly, or change your settings.


With the setup you provided, if your subjects are 5 feet away, you have a total of .32 feet or about 4 inches of depth that will be in focus. Therefore, your subjects need to be equal distance from the lens, to be in focus. This will require measurements to be sure of focus most likely, therefore, you may want to consider changing your set up to be more favorable to ensuring sharpness of focus:




  • If you stand 10 feet away, you have 1.3 feet of area in focus.




  • Better yet, if you change your aperture to f/8, you have about 1.5 feet of focal depth, so any offset distance between two side-by-side subjects will be minor, and both will likely be in focus.





To calculate these distances, refer to the excellent, and always helpful DOF Master


No comments:

Post a Comment

Why is the front element of a telephoto lens larger than a wide angle lens?

A wide angle lens has a wide angle of view, therefore it would make sense that the front of the lens would also be wide. A telephoto lens ha...