6.22.2017

Focal length is a big part of a portrait vision. I prefer longer focal lengths. This portrait was shot at 189mm.


Given the choice I'll nearly always shoot longer and longer rather than shorter when it comes to making portraits. There is something about the compression, blended with lighting that helps accentuate the topology of a face, that makes a portrait seem more real to me. When the first digital cameras with interchangeable lenses hit the market in the early part of the century almost every model came complete with an APS-C sized sensor. I was amazed at the number of people who thought nothing of shooting portraits with their 50mm lenses on those cameras. While the 50mm focal length translates to about a 75mm equivalent on a full frame camera I think that's still more than a bit short for good compression when making portraits. 

We could be pedantic and suggest that the 75mm user back up a bit and then crop and that the results would match a longer lens but we know there's other stuff at play. In the early digital days part of the equation was a resistance to cropping in order to ensure there were enough pixels left over to make a decent image. I'd say that if one is shooting on full frame cameras and cropping square the same reservations apply. 

In the best of all possible worlds I'd use something in the range of 135 to 200mm for a studio portrait and I'd also specify that my background be yards and yards behind my subject instead of mere feet. The further away the background the easier it is to drop out of focus and also to light as a totally separate plane. If we put the background very far back we soon see another reason to go longer with our portrait lenses. A shorter lens will show the edges of the background sooner and will limit our ability to push it back as far as we can. In essence, a long portrait lens, delivers more options for the relationship between the subject and background. 

There are a few downsides to using a long lens for a portrait. If you light faces in one of the current styles that calls for flat and even light across a face you'll find the compression makes the face seem wider; fatter. This is rarely a benefit to the subject. When we compose with long lenses I try to create light with quicker gradations to shadow in order to create a more three dimensional rendering to the face. I'm trying to bring back a normal geometry to the face with my lights. 

One more thing about lighting. I like to make sure that the bottom edge my main light is up well above chin level on my subject so a shadow drops in under the chin and gives a visual depth between the chin and the neck/throat. Alaina certainly does not have a double chin to worry about but many corporate subjects do and it's benevolent to make sure that a well placed shadow, created by correct lighting, does its part to conceal certain...flaws. 

The photograph above was done with a Sony 70/200mm f4.0 G lens on an A7ii camera body. 

Of course, you can always ignore these conventions and shoot wider. But eventually you'll come to hate the look and probably give up photography altogether. Wide angle portraits can be that bad... You'll notice that even Bill Brandt only dabbled with wide portraits a handful of times....

9 comments:

Christer said...

Zeiss just brought out their new 1.4 35 mm Milvus and here's what they said about it:

"With a wide 35 mm focal length, this lens opens up a world of possibilities. From making your portrait subject stand out against the background to . . ."

But then again, this is what they said about their 2.0 135mm Milvus: it is perfect for medium-distance portrait photography." And "The ZEISS Milvus 2/135 permits an interplay between fore- and background that is simply incomparable."

Obviously, to Zeiss, it does not matter if you shoot 35 or 135mm, everything will be "breathtaking".

Anonymous said...

Hi Kirk, thank you for the practical and useful thoughts. I like 135mm because it offers a great balance and natural look. My personal favourite is the Leica APO-Telyt 135mm f/3.4 because of its light weight handling and the results I get, but there are heaps of great choices out there.

Roger Bradbury said...

What are the shortest and longest subject distances you'll use? Some of us will frame wider, some tighter than you, so wouldn't necessarily choose the same focal length to get the same perspective. For example, I've been taking some informal portraits at 50mm on APS-C, but they've been half lengths. I suppose I was at about 6'.

Either way, I bet your shortest distance is a lot longer than the 2'3" most selfies are taken at... : )

Anonymous said...

@Roger: look at Ken Rockwell site, somewhere there is an article about portrait lenses, and he has compiled an interesting technical table about focal lengths for portraits. Technically it is exactly the same what Kirk says, which means that a cheap "longer zoom" kit lens is more suitable for portraits than a dedicated 75mm-90mm equivalent lens sold as "portrait"!

Kirk, I am wondering what did you do with MF? The lenses had to have about twice the focal length. I remember that on some old photos you published on the blog, it was 150mm, that is, about 75mm focal length for 35mm format. I guess, the lens choice was not the same as for 35mm SLRs.

Kirk Tuck said...

Hi Roger, while I used my 150mm a lot back in the MF film days my favorite portrait lenses for the Hasselblad were the 180mm f4.0 and especially the 250mm f5.6. The compression out of the 250mm, along with the limited d.o.f. was just tremendous. Plus, back then we have a lot more real estate with which to crop...

If I were limited to two H-Blad lenses it would be the 100mm f3.5 Planar; my favorite normal, and the 180mm f4.0; the most adaptable of the portrait lenses (and wicked sharp).

Kirk Tuck said...

Hi Roger, my reply just above was really intended for Anonymous but I saw your name at the lead in. Here's the answer for your question. I hate to go in closer than six feet. Eight feet is usually more comfortable but as to a maximum camera to subject distance I've never quite figured that out. I think 15-20 feet as I want to stay "in the conversational space" with whomever I am photographing.

Roger Bradbury said...

Hi Anonymous, thanks for that. I get the impression that Ken Rockwell likes to work at very long distances. That seems a bit extreme to me as I think that a great distance gives a flat perspective, which makes the subject look too remote. However, he is the only person I've found on the net who talks about subject distance, not just focal length choice.

Hi Ken, that's just what I wanted to know. Thanks for that. Since I've started asking strangers if I can take their photo instead of just taking a candid shot, I've thought about this. I see what you mean about eight feet being more comfortable.

You seem to be working to normal human communication and interaction distances, though with a longer minimum distance because of perspective, and because you might not know the subject too well.

Anonymous said...

Roger, the interesting thing is, the suggestion of 5 meter distance, bit more or less, is soooo simple - you do not need to think about all those equivalences with different formats, no things like "oh, this is a portrait lens, and this one is for ...". And it really translates to what Kirk said above - a good headshot would be with 200mm, and half height (or how do you say it) is okay with 90mm.

However, the expression, the mood you show, is more important. I just look at my amateur photos made with amateur 40mm lens (hmmm, some of them :) ), and do not really care about the distance or focal length.

Roger Bradbury said...

Anonymous, This is going back to my original question. What do you call a good headshot? Some will like a good amount of room around the subject, some will crop so close you can't see the ears. That all depends on the photographer's intent, and they'll choose a lens to suit. But it's the subject distance for this sort of photography that is for me, the thing.