On a photographers’ forum last week there was a lot of discussion about the best lens for portraits. Can of worms opened. Mac vs PC or Nikon vs Canon style debate well and truly started.

I have written before about portrait lenses and I won’t bore you with repeating my previous post (if you missed it, catch up here) except to say that when people ask this question they normally mean headshots or mug shots where the subjects head and shoulders will fill most of the frame.

This portrait of a local artist was shot using an 85mm f1.8 Canon lens wide open but what lens should you use for this kind of picture. The debate will rage and answers anywhere between 85mm and 135mm (all measured on full-frame cameras) will be given, supported, doubted and even ridiculed. Most arguments that don’t get broad agreement also don’t have a simple answer. Sure there’s something lovely about the feel of a portrait shot on an 85 but what about the degree to which you have to invade the subject’s ‘personal space’ to get the composition? What about those 85mm lenses where the close focus isn’t good enough to get that bit tighter still? With a 135mm lens the personal space issues largely go away and the close focus issues almost always go away too – but is the effect as nice? Can you ever include something of the environment in those pictures? Would you even want to?

The actual answer (as always) is that it depends on you, your technique and your own taste in pictures. A few weeks ago I was looking back at some corporate headshots that I had shot and I had to tell another photographer on the other side of the world how I had shot them so that he could replicate them so that when his pictures and my pictures were printed on the same page nobody (hopefully) could tell that two photographers were involved. One of the things I needed to give him was the focal length of the lens used so I got the pictures, went through the EXIF data and noted it all down. I had used a 70-200 f2.8L lens and so the actual focal length was between 120mm and 130mm.

I was a little surprised that it was that long and so I grabbed a folder of images that I keep on my hard drive of corporate portraits to show prospective clients some examples of what I have done in the past and looked through the EXIF on those. These were pictures that, by definition, I really like and it quickly transpired that the tighter compositions were all shot between 120mm and 150mm on the 70-200. Again, quite a surprise – I had always seen myself as an 85mm lens user!

Well, one thing led to another and I decided to do a quick ‘audit’ of all of my favourite environmental portraits to see what lenses I have favoured. This was less of a shock because in the folder of 120 of my favourites the widest lens used was 16mm (on a 1.3x crop body, so we’ll call that 21mm for the purposes of this exercise) and the longest was a 300mm (on a 1.6x crop body which becomes 480mm in this context). There was a lot of bunching in the 35-45mm area and some more around the 120-150 area but the spread of focal lengths was otherwise pretty even – which pleased me greatly because it confirmed what I always say to others;

“There is no such thing as THE perfect portrait lens”.

This exercise is a bit time-consuming but it could have a lot of uses in professional photography. For example, anyone used to zooms wanting to buy a couple of prime lenses should think about going through the exercise to help them decide which ones would suit their style. Anyone wanting to know what lenses to replace as a matter of priority in these cash-strapped times could also benefit from a focal length analysis. The reverse is also true – a photographer who wants to change the way they do stuff could see what they normally shoot with and deliberately avoid those focal lengths. The possibilities are endless once you start to think and we can all do with a bit of style analysis from time to time. How we choose and use lenses has always been a preoccupation of mine and this exercise has helped me to rationalise that.

Indeed why stop there? EXIF data is amazingly useful and so you could also do an aperture comparison. My quick one revealed that I shoot a surprisingly large amount of pictures using three apertures f2.8, f8 and f22. In my sample, those three apertures accounted for over 50% of my pictures. I’m not sure what to make of it but I will work it out one day.

What started out as a simple answer to a simple question somehow turned into statistical analysis. Many people would say that is the exact opposite (they might even use the word antithesis) of what we, as creative people, should be doing. I have a lot of sympathy for that argument but, in a world where there are tens of thousands of great photographers vying for work, every little advantage we can eek out for ourselves and every piece of information that we have to work with could just be worth it’s weight in fluorite glass.