The purchase of my new Tamron SP 90mm VC USD (f017) Macro lens has been accompanied by two separate yet ultimately interlinking trains of thought, the first by a feature of the lens which allows it to use an aperture setting of f/64, and the second a dialogue I recently had with bird photographer Keith Bauer of the Nature Photographers’s Network about what constitutes good bird and wildlife photography.
Having spent years meticulously photographing birds, ensuring that his images did not contain any other “clutter”, and modelling his work on what he saw in books which identified different species of bird, Keith** came to a gradual realization that something was missing, and that this was the environment in which the birds lived and actively related to. He began to include more and more of the environment into his images, and he liked the result.
Having agreed with Keith’s philosophy on this, I can see the same issues at work in the world of (nature) macro photography. The ideal is so often repeated that the subject must be isolated from its environment. The nature of Macro, where close-up work means that macro lenses must have a very narrow depth of field, is often considered an advantage because it ensures that all but the subject is an indistinct bokeh (ooh! ….the extasy of creamy bokeh!!).
The world of macro is divided into two distinct camps, the one working indoors with all kinds of focus rails and special lighting systems, and whose end is the photography of single objects where every single part is razor-sharp, and the other, out in the field, where focus stacking is not practicable because the subject cannot be relied upon to be still, and photographers are trained to ensure that at least the eye is in focus, and it is at least accepted (if not welcomed) that the remainder of the image fades into a blur.
Being generally in the “including the environment is good” camp, I looked with some excitement at the ability of this Tamron lens to go as far as f/64. But I had creeping doubts, as almost every self-respecting photographer and reviewer worth their salt repeats the view in perfect unison that the/she would never dream of having a smaller aperture than that at f/22 because images thus created would be unacceptably soft as the result of diffraction.
So why bring out a lens which goes to f/64, unless this lens has characteristics which make f/64 a real option for good quality photographs? Review after review had not even mentioned this feature, only the maximum aperture of f/2.8 which is only useful when the lens is used for portraiture, and is definitely not at all useful for the macro photographer. But in online discussions, anyone mentioning the possibility of using higher f-stops than f/22 is responded to as if a total greenhorn!
However, my thinking about this was that I would rather have a small amount of softness throughout an image than have a small slither razor-sharp and the rest of the blur, because I like to get really close-up, but at the same time not having the environment totally blurred (and being in nature, cannot focus-stack because things move, and because one generally has to act quickly to photograph insects and bugs). So the only question was: is the softness that bad, or just one feature which can be played off against others such as depth of field?
I decided to give the feature a trial, which I present here NOT as a scientific study, but as a discussion point.
The attached image shows the same image of nectarines in unedited images at five different aperture settings: f/64, f/32, f/16, f/8, f5.6*. The images have no particular artistic merit, and no discussion is being initiated therefore over whether such an image in particular benefits from a larger or smaller depth of field. The function of the image is : 1) to showcase the possible benefits of thinking positively about f/64 as a viable option for macro photography; 2) to compare the depth of field of different f-stops 3) to demonstrate whether or not images created using f/64 are too “soft” to be of any effective merit.
These nectarines were about half the dimensions of a typical apple. I have to say that I needed to look on the screen at about ten times the size of the actual fruit before I could detect any trace of softness in the f/64 image. At that point I could see that there was a very small difference between parts of the stalk of the main nectarine in the f/64 and f/16 image; on the other hand, in the latter I was noticing that some parts of this tiny stalk were slightly out of focus, because of the smaller depth of field. Yet even when blown up to full screen I was not bothered by the f/64 image being too soft. I will repeat that it is not my intention to be making a judgement on whether this particular image is better suited to wide or narrow depth of field, and that the image itself is not supposed to have any artistic merit.
I would very much welcome any views on this issue. My own personal conclusion is that f/64 is a great possibility for macro photographers who are interested in seeing small creatures or plants in their setting. On the flip side, a setting of f/64 requires much more light, but with the advent of better and better lighting systems for macro photographers which are not unduly expensive, combined with the fact that high-ISO photography is improving all the time and now does not mean accepting a lot of noise in the image….
So, at least let a discussion begin about this issue!
* A detail: Nikon alone of all manufacturers use a system of “effective apertures” which mean that very close up the largest aperture effectively is f/5.6 and the largest f/64. Canon and other manufacturers, for example, would still measure these as f/2.8 and f/32 respectively. My Tamron lens, made for a Nikon full frame mount, uses the Nikon measures.
** Please see the post regarding Keith Bauer’s article on this page