Now, I've been writing a lot how satisfied I am with the Batis 2/40 CF. And it's true, I am satisfied with it, for example the focal length is very versatile, just like I wrote yesterday. But it would be quite pretentious if I would say that haven't had any concerns with the lens. Well, of course I had my concerns with the fw-update and if it would fix the Eye-AF issue (it did). But having a lens for couple of months only for myself (meaning not writing a blog) I've also questioned if the maximum aperture of f/2 is enough? It's definitely a moderately fast aperture, but it's not very fast like f/1.4 or even larger apertures available. So, naturally this got me thinking if I am losing something in my images by not being able to shoot, say a stop faster aperture at f/1.4?
With the new camera bodies the maximum aperture is all about getting the shallow depth of field and not so much anymore about light transmission or being able to shoot at lower ISOs (for example, with the A7III I've shot at ISO12800 with good results). So in practice the difference between f/2 and f/1.4 means that one can have even more shallow depth of field. But the essential question is: how shallow do you want it? I had to think this very hard to realize that it's not just the shallow depth of field that I want (the blurry bokeh balls doesn't have much of a photographic value on their own). More explicitly I want to have a good subject separation so that my images would have a certain punch - especially so when shooting at 40mm which is still moderately wide field of view. In some certain situation I might want just the shallow depth of field, but in majority of cases it is really the subject separation that I'm after. So, how do you get the best subject separation?
Here's how I see it: one can imagine a one dimensional line where there are small apertures (eg. f/8) at the one end and the large apertures (f/1.4) at the other end. Where do you locate the best perceived subject separation on that line? Does the subject separation get better if you move to larger apertures? Is the best perceived subject separation achieved at the far end of the line at f/1.4, or would you get even better subject separation if the line would continue to f/1.2? Or why not continue it straight away to f/0.95 or even to ‘Kubrickian’ f/0.7? I’m sure you have already understood my point: there is not a single ‘best subject separation point’ on that line because a good subject separation depends on so many different things like the subject distance, background distance, three dimensional shape of the captured subject and so on. To have your subject pop from the image you often need to have a somewhat clear subject contour and a good contrast against the background, and therefore you often need to stop the lens down for the best subject separation. In other words, it’s definitely not enough to be lazy and just shoot as wide as possible aperture, instead you have to consider the aperture individually for different scenarios and choose the right setting based on what you are photographing. Like everything else in photography it's a craft that takes a bit of learning.
Once I understood this I decided that for me the f/2 on a full frame camera offers a plenty of subject separation potential. Actually when I’m close enough to my subject I try to avoid it because I don’t want to lose the punch of the image. For example, just the other day I was shooting kids washing their bicycles for the spring and later on when checking the pictures at computer I thought to myself that I should have used f/4 or f/5.6 instead of f/2.8, which I was using for the most of the shots. To be honest, it’s difficult to resist to shoot with large apertures, but most of the time it just reduces the overall punch of the image, and the background bokeh doesn’t get much more interesting either (and only the ‘camera nerds’ are really more interested in bokeh than the actual subject of the image). With the f/1.4 lens I’m sure I would produce a lot more overly blurry images just because I could open it up a stop more.
And if you are printing your pictures then using the widest possible aperture makes even less sense because the it’s very difficult to translate the maximum sharpness into a physical surface. In paper and other similar surfaces, the individual pigments are always a bit mixed with each other, which means that the maximum sharpness and acutance are decreased in the process. If you have a f/1.4 picture with a very small area in focus (like eye slashes or such), the overall result almost always look like there nothing is in focus because the sharpness and acutance of that particular area is decreased and in effect it doesn’t pop up from the whole picture. ‘A miss focused shot’ would the average Joe say and while it breaks the heart of the discerning photographer, he is kind of right. Stop the aperture down to say f/4 and suddenly you have a picture with high contrast and acutance, which also has a good pop and subject separation. I know that these kind of thoughts kind of goes ‘against the grain’ with the current trend of f/1.4 lenses, but in my experience it rings the truth. As fabulous the f/1.4 feels it can also lead to mushy and blurry pictures which can’t stand the test of time. And of course the same goes with the f/2 as well, which is why I try to remain critical when shooting wide open: does it really add anything to my pictures or am I just shooting wide open because I don’t have any other photographic idea for the particular scenario. But before you get on your horses, I have to add that I’m not against f/1.4 (or f/2) at all, I just think shooting wide open all the time makes the pictures look more or less tiring and might compromise your work. Sure, the wide open look has its places, and used seldom it often gives the best punch to those pictures within the bigger body of work.
So, with these kind of thoughts and some real life experiments I decided that the f/2 maximum aperture of the Batis 2/40 CF is perfectly fine for me and I'm not losing anything by not having a stop faster glass. But it was not easy to come into this conclusion, I really had to process it and think it through with some real life experiments before I could come into this conclusion. But now that I've done it, I think I have all the subject separation that I need (and even more that is any good for my images). On top that I've started to appreciate this limit in a different way: starting from f/2 the Batis 2/40 CF gives me a pretty good and rational aperture range where I usually work between f/2 - f/5.6 – and I don't need the f/1.4 because it would likely to just mess up my preference for the good perceived subject separation. And it of course saves some weight which makes the shooting more comfortable and convenient. So, in the end, and personally to me, it's a win-win situation. And in some odd way I feel more of a deliberate photographer now that I've resisted 'the f/1.4 mania' with some rational arguments and I feel good about it. Of course, others might feel different, and it's ok because there's room for everyone, but personally I'm peace with the f/2.
For the end of this blog post here are some images taken with various apertures. Now, this is a pretty ad-hoc set since none these are really prepared for the blog (sorry for the mundane subjects), but I think my thoughts are hopefully better understood with some examples. I hope these will help you understand what kind of subject separation is possible with the Batis 2/40 CF (ie. pay attention to aperture settings).