Focal Lengths - prime lenses for headshots

Tutorial: Focal Lengths for Portraits

I've planning to start doing some basic photography tutorial posts, talking about the things I know about and using my photos to demonstrate simple concepts. This post is about using different focal lengths when photographing people. I'm talking about lenses on a crop sensor dslr, so they are equivalent to about 44mm, 80mm, and 130mm on a full frame, but with more distortion.

Same Distance, Different Focal Length

The three photos above are taken at three different focal lengths with the camera (on a tripod) and subject in exactly the same place. In this case I'm using three different prime lenses, but the effect is the same as standing in the same place and zooming in and out on the subject. The camera is about seven feet from the subject. Notice how the subject (Michelle) looks undistorted in all the photos, but that the framing changes significantly to include less. Compare that to the sequence below.

Same Framing, Different Focal Length

In this sequence, I have changed the distance from the subject, as well as the focal length, in order to keep the same framing - to keep the subject the same size in the photo.
Comparing focal lengths of lenses for portraits

You can see that at 28mm Michelle looks distorted - the centre of the picture is enlarged making her nose look bigger, and her ears disappear behind her cheeks generally making her face look chubbier. At 50mm there's much less distortion and from here we have a more flattering portrait. At 85mm things look pretty similar - there is no distortion and it's a good portrait length. The picture is very slightly flatter, and this would be more apparent with a background.

Photographing People

If you find your photos of people (or yourself) look like the first picture above - try standing further back. It might seem obvious, but the closer you get, the more distorted your subject's face will seem. Try doing a comparison like the one I've shown above using your own camera - try to frame your subject in the same way, but use different focal lengths - then compare the results so you know what you're going to get. There might be times where you want a wide angle look. Here's an example of a wider angle used for effect:

28mm Example:

Wide angle portrait

The wider angle includes more of the background and gives much more of a context to the portrait - as well as slightly distorting the subject to give him a peering, reserved look. Actually this was taken by my brother who is not a photographer, so he just went up and framed the subject in the middle, and the poor chap is looking a bit skeptical about having the camera stuck so close to his face. But I think the effect is excellent and it looks entirely intentional. So this just goes to show, you don't have to stick with any perceived rules about how to do portraits.

50mm Example:

Elena Chepel

This photo of Elena is a similar attempt to put the subject in context, but with a slightly longer focal length of 50mm. This means the subject is undistorted and looks good, but the framing still gives context to what she's doing - it has a story to it.

85mm Example

85mm Example - Michelle Li

In this example the subject is completely isolated and the photo becomes all about her face and expression. I haven't really talked about depth of field, and that will be a subject for another post, but the longer the focal length, the tighter it is possible to make the depth of field (assuming all else, such as aperture, is equal). This is shot at f/2.0, as are all the other examples of Michelle.

I'm still working out how best to do this kind of tutorial, so if you have any feedback it would be very useful if you comment below.

2 thoughts on “Tutorial: Focal Lengths for Portraits”

  1. This is such a great idea for a very amateur photographer like myself Ivor!
    I found the comparison of the the two ‘trios’ of photos of Michelle a little confusing – I think because I wasnt sure how the 28, 50 and 85mm on the photos related to the 44 80 and 130 mm you mention in the text.
    But your explanation of how to avoid distortion by standing further back is well explained (and news to me!!).
    Can I ask (what is potentially a dumb)question? :-) If you stand further back as explained and then in Lightroom/Photoshop you crop to enlarge do you still avoid distortion?

    PS. Your large portrait of Michelle is stunning!

    1. Thanks Anne!

      That’s very helpful to know – you’re right, I don’t explain the effective focal lengths thing very well. That’s because I’m using the 28, 50 and 85 on a crop sensor camera. The sensor is smaller in the camera than in a full frame camera, and the measurements 28, 50 and 85 describe what they would be on a full frame. On a crop sensor they are effectively multiplied by 1.6. Other cameras will have different sized sensors too – here’s a graphic:

      Also a good question about standing back and cropping – you avoid noticeable distortion if your subject is in the middle of the frame, but it gets more complicated if they’re towards the edges where you will have more distortion on a wider lens. If you’re using lightroom you can enable profile corrections, which will try to automatically detect your lens and fix the distortion, which will to some extent fix things further out from the centre. However, it can’t correct a close up wide angle portrait like the second 28mm example. It corrects the roundness, or ‘fish-eye’ness, but not the lost information like the ears! I would still advise if you want a flattering portrait is to use at least a 50mm focal length, and just stand further back. That goes for groups of people, full length shots and so on. In fact, with a full length shot I would go even further away and use an even longer lens (the 85mm), and get down to waist level. That would be another good example for me to shoot.

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