Reading time: 4 min| The other word is plasticity. It seems that plasticity is the god-given natural state of striving for a sculptor. Why not for everyone else? Besides, dimensionality sounds so pompous and convincing. It must be outstanding!
As a kid, I considered reliefs in their halfway state between picture and sculpture to be an unconvincing compromise, even if the content and design were modern and exciting. When looking at them, I felt annoyance and the feeling of a lost sandwich I hadn’t entirely eaten. Today, my liberal soul tells me reliefs to be as valuable as sculptures and paintings. But I’m still not much drawn to them.
When I was standing in front of a sculpture, my father used to tell me how beautiful it was. He actually enjoyed all sculptures he came across, somewhat arbitrarily. As a scientist, his explanation of why he liked sculptures had a philosophical twist: you can look behind the image by moving yourself behind the object.
Whilst I still like that idea very much, today I know that plasticity, or dimensionality for that matter, is not an argument per se for why work is excellent. It’s just another stylistic device that may work in a specific context or not.
This brings me to photography (be it moving pictures or stills) because that’s my medium of expression.
To wrap our heads around dimensionality in photography, we must understand a few things. Firstly, when all things are equal (sensor size and focal length), lenses of different manufacturers and types show roughly the same field of view, which is the angle of what we look at when looking through the camera. Naturally, the field of view at a given standpoint is essential for framing the picture. What’s more, the field of view also determines how we perceive the depth of a photograph. A wide field of view adds depth to a certain extent because the distances of objects look stretched out. With a smaller field of view, the picture’s character changes to a more compressed expression of depth. To sum up, wide-angle lenses show a deeper depth; a long telephoto lens compresses the depth of a scene.
But why do lenses of the same field of view, the same focal length and the same f-stop on the same camera can deliver a vastly different expression of depth, aka dimensionality or plasticity?
Well, that’s due to many variables, being the focus fall-off the most notable one. Focus fall-off is how a lens renders the focus in the different distances between the sharp foreground and the out-of-focus, blurred background. One interesting variable in this game is the concept of a bend focus plane, the picture’s imaginary plane in a given distance, resulting in a constant blur when straight. But if the focus plane is bent, the blur in the centre of a picture may vary compared to the corners at a given object distance.
Naturally, lens engineers do what engineers always do and make things right. That means, in this case, as time and knowledge processed, that focus planes became straighter and straighter to eliminate soft corners at infinity (essential for landscape photography). On the way of improvement, lenses tended to lose what we call personality, which is entirely a collection of issues we like and call character. But, of course, there are also modern lenses with straight focus planes that show character because, in art, everything is not black and white but complicated and hugely subjectively.
We could stop here and call it a day because conservations tend to reach their end whenever the term subjective is on the table. But fortunately, in all the subjectiveness, there is one expression in lenses that even the most untrained eye can see: dimensionality, plasticity, depth or, for the younger folks, 3D-pop.
The following pictures have been shot with two lenses at roughly the same focal lengths and field of view (50 mm, which pictures our human vision of an environment’s depth). Both come from the same manufacturer, in that case, Leica. The first is a modern zoom lens that resembles meticulously what modern lens engineering can pull off. The second lens is a prime lens (prime lenses cannot vary their field of view) from the mid 70ies, which, back then, has been regarded to be the pinnacle of the 50 mm stills prime for full-frame SLRs.
As we can see, the two lenses show a different character in terms of dimensionality. The zoom shows pronounced plasticity or 3D-pop, whilst the 70ies prime renders much flatter pictures and slightly wider faces.
So, what to do with that?
If a powerful expression is on the table, the zoom wins, hands down (it’s also much sharper regarding resolution, which matters in landscape photography). But if a more flattering portrait is the task, if images will end up with graphics such as letterings, the flatter rendering of the vintage 50 mm primes seems more appropriate.
With that, I’ll leave you with the insight that, if even lens choice matters, how much more will subject, background, light, and colour matter? Infinitely more. Would we see the lens’ expression without a direct comparison? Hardly. Does it matter then? Yes, it does. It’s one piece of the puzzle. And when one dives into the vast ocean called photography, at some point, lens characters become vital because that will drive your shooting habit and motivation besides the particular rendering of that lens.