‘Depth of field’ or DOF for short is this nice image quality where one piece of your picture is sharp and in focus, and the rest of the image is blurred and out of focus. Pictures with a shallow DOF isolate the sharp object, like a face, from the background. Great to draw the audience’s attention to the subject.
Video camera’s like the Sony EX1 are designed for versatile deployment and quick handling. A shallow DOF makes a cameraman’s work harder since he/she needs to adjust the focus a lot. So the EX1 doesn’t usually give a great looking DOF. However, applying these tips you can get the maximum DOF and in many cases it’s (more than) enough.
- Make sure there is some distance between your sharp subject and the background. The more the better.
- Take some distance from your subject and zoom in a little. Go for the 50mm feel. Don’t zoom in too much or your image feels crushed and small.
- Open up your iris, the low numbers like 2.8. Put the iris on automatic and use the ND filters to get the lowest possible numbers. You can do everything manual but putting only the iris on auto you can work quicker.
- Don’t use your shutter speed to control the DOF. I usually keep my shutter on 180 degrees, or 1/50. Only use high shutter speeds for fast moving objects like the Top Gear race look.
- Avoid using the gain to control the exposure. 0dB has the least noise though some people prefer -3 dB. Remember: 0dB is about 400 ISO and every 6 dB doubles the ISO.
- You can buy screw-on Neutral Density filters to control the iris even more. There ‘fader’ ND filters are great and give an extra 1 to 8 stops when you rotate them.
DOF is hot, thanks to the film-look loving DSLR revolution. However, be careful. I have seen examples where the DOF is way too much and you cannot tell where the subject is. Could be a studio, his house or even Mars? You need some reference in the out of focus background.
O yeah, one more thing about the iris, never let your iris go over 5.6. while outdoors. If you know the EX1, you will know that blue skylines sometimes look dirty at the edges. This phenomenon is called blue fringing and if you keep your iris under 5.6 you’re good.
