Posts Tagged ‘portraiture’
Why are certain lenses called ‘portrait’ lenses? Because its all about the perspective!
Classic portraits portray the best version of the person and part of that is not exaggerating features. We have a view of people that we normally see. Features looks normal at this distance and generally the person looks like the ‘normal self’. When you change your distance to the subject, your perspective changes. Features, such as a nose or lips, become more exaggerated. It’s not the focal length itself that changes your perspective, but the fact that you have to move closer or further back to keep the same composition with a different focal length.
To demonstrate this, here’s a series of pictures (the first half of which use the lovely Nikkor 70-200mm f/2.8 VR II on loan from our program) to demonstrate the fact. This is on a crop sensor camera, so the classic portrait range starts around 50mm but can be pushed to 35mm. These start from 200mm and end down to 18mm. See how the nose gets more exaggerated slowly and by the end is enormous! Each shot is framed approximately the same. I zoomed out and took a step in to keep the framing the same.
At this point, you can see the nose is clearly more prominent than at 200mm. Is it a problem though? Not at all.
Up until this point, the features look pretty standard, nothing major happening.
The features on the front of the face are clearly larger here! We’ve moved outside the ‘portrait range’ and it’s evident why the range exists!
So the change in perspective becomes pretty obvious by the end and you can see why the 50mm is the standard ‘start’ of the portrait lens length on crop sensor bodies. The features start to distort shortly after it. You could use 35mm on a crop sensor body in a pinch though.
I photograph people. You can use any lens, any lighting, and any technique you like but some things just work for portraits. In this post and some futures ones, we’ll cover a few lens options (this is not an exhaustive list) at various price points for doing portraits. These pictures were taken on a APS-C sized sensor, so if you’re working with full frame, you’ll need to consider that in your working distance. These aren’t meant to be full review of the lenses, but of how they perform for portraiture.
OPTION: 50mm fast prime – 100 USD to 500 USD for most options, depending on mount, brand, at either f/1.8 or f/1.4
The lens used below is a Sigma 50mm f/1.4 EX DG HSM. It has an excellent build, feels good in the hand, focuses fast (although not as fast as a higher end Nikkor AF-S), but this particular 50mm is a tad on the heavy side. Fundamentally, you should be able to get approximately the same shots from most 50mm lenses. Its rare for me to shoot at f/1.4 so for the most part an f/1.8 lens will work (I usually stop down for increased sharpness).
What we’re aiming for here is sharp features, good separation from the background, and the background sufficiently blurred so that it doesn’t distract. The image is more or less successful here. The features are sharp, the woman stands out from background fine, but if anything, the background is not sufficiently blurred. The bokeh isn’t bad, but it doesn’t quite ‘blur’ together. I could have stopped down more and perhaps blurred it more, but most nifty fifties in this range appear to have about this quality of bokeh. Not bad, but not ‘super creamy dreamy’. Subject feature compression, more is better generally, is a function of the distance to the subject. A shorter focal length requires you to stand closer which results in less compression. The 50mm is the edge of what is ‘ok’ here. The features aren’t exaggerated but they’re not particularly minimized. We’ll see other options to address compression.
Overall, the fast 50mm on a APS-C body makes a fine portrait lens but a greater focal length would allow us to stand further back and increase the feature compression. Of course each brand and specific lens will vary somewhat.
OPTION: Super telephoto – 150 USD to 300 USD for 200mm’ish range, not particularly fast with a largest aperture of f/4-f/5.6.
The lens used below is a Sigma 70-300mm f/4-5.6 APO DG. These, and their name brand counterparts, are the lenses that many people get as their second lens. They’re often sold in combination ‘deal’ packs with starter cameras. They’re super telephoto lenses that start in the 50-70mm range and end in the 200-300mm range. They’re typically slow on the maximum aperture and, generally, aren’t known for their excellent optics. The pros will use this same focal length, but with a fast and constant f/2.8 aperture (we’ll cover that lens in another post).
Portraits aren’t only for people! The more exaggerated features will make this point more obvious. What we’re looking for here is the increased compression. The features like noses and chins should not stand out. However, we don’t want to lose subject sharpness, separation, or background blur. The giant mouth and chin are minimized such that for a portrait the compression is certainly effective here. But we’ve traded on sharpness and especially background blur. The out of focus highlights are individual and sharper – they don’t run together to produce a ‘creamy’ scene behind. This is usually a function of the quality of the lens and the fact that its maximum aperture is rather slow.
Overall, these lenses provide adequate portraiture but often lack in sharpness and especially bokeh quality. Of course each brand and specific lens will vary somewhat.
OPTION: 85mm top end, fast prime – 1700′ish USD for an f/1.4 (or Canon users have a f/1.2 option).
The lens used below is the Nikkor 85mm f/1.4G AF-S. It’s a professional level lens with a professional level price tag of around 1700 USD. The build quality is excellent on the lens (although the 50mm Sigma has about the same weight and quality feel) and its focusing is fast, but not superb. It has a maximum aperture of f/1.4 that produces great, creamy backgrounds but was often too fast for outdoors without a ND filter.
The features are sharp, there’s good separation from the background, the background itself is uber-creamy, and we’ve got enough compression that the features are minimized. The focal length is perfect and what 1.7k USD buys you is that amazing creamy background. There aren’t any individual circles and it looks more like a water color painting in the background. Overall, you get what you pay for with this lens. It’s not without fault though. It’s heavy for a prime lens that you’ll want to shoot handheld and it’s focusing speed definitely lends itself to planned portraits more than action.
Overall, if you’ve got the dough, its an excellent, professional portrait lens.
These are not all the options, but they’re common options for portraiture. In the future, we’ll cover a f/2.8 macro lens in the 100mm range, the 70-200mm f/2.8 lens (a favorite of the pros), and a wide angle lens (just for comparison’s sake).