Overcoming Depth of Field Problems in Portraits

“Can you help me with a recurring problem I seem to be having in my portrait shots? I’ve noticed lately that I’m getting a lot of shots with some parts of my subject’s face in focus but other parts of their face out of focus. I’m using a Canon DSLR (Rebel) with a 50mm f/1.8 lens without a flash – mainly indoors. Can you help?”

Without seeing the actual images that you’re talking about it is a little difficult to assess what the problem is – however it sounds to me as though you’re probably shooting at the maximum aperture and might want to think about making a few changes.

The great thing about a lens like a 50mm f/1.8 is that it’s a nice and fast lens which is ideal for shooting in low light conditions. However the problem is that in shooting at such a large aperture the depth of field that will result will be quite narrow (learn more about DOF). This makes focussing difficult as you’ll find some parts of the image can be pin sharp while others are not.

For example check out this shot of my son – you can see his eyes are sharp but his nose and ears are not – the DOF is narrow (this was shot at f/4 – so you can imagine what would it would have been like opened up even further).

Extremely narrow depth of field can actually create some stunning effects – but when photographing portraits where you want to get the full face in focus it can also mean you take a lot of fairly unusable shots.

How to Overcome Depth of Field that is too Shallow

What I’d suggest you do is experiment with choosing a smaller Aperture (a larger number). Try experimenting with apertures in the middle of your lens’s aperture range. This will mean your depth of field increases and you might also find that your images become sharper also as a result of shooting within the sweet spot of your lens.

Keep in mind that using smaller apertures means that you need to compensate for the smaller opening in your lens and the smaller amount of light that it lets in. There are a number of ways you can do this:

• Light Your Subject – make sure your subject more brightly lit. You can achieve this by using a flash, opening some windows to let more natural light in or using some other source of artificial light (the room’s light or a purpose built photographic lamp). I personally supplement the ambient light in indoor photography with a flash – usually bounced off a ceiling or wall.
• Increase the ISO – another way to compensate for the smaller aperture is to increase the sensitivity of your image sensor by increasing the ISO setting. Doing this will increase the ‘noise’ or pixilation in your shot but even just to increase your ISO a step or two will allow you to choose a smaller aperture.
• Decrease Shutter Speed – when shooting people (moving subjects) you’ll be limited in how much you can decrease the shutter speed that you’re shooting at – but it is one possible way to compensate for a smaller aperture.

Once you’ve taken some shots head over to our forum to share your results in the Portraits Section.