© Niall Benvie 2009
Since I took my first flower photographs over 30 years ago, I have used a wide variety of approaches to flatter my subjects. But my current one, relying on artificial lighting and a white background, is a big departure – and one that challenges traditional notions of “nature photography”.
At first glance, it is easy to assume that these pictures were made in a studio. In one sense they are – but that studio is on location, built around the subject. The lighting is almost shadowless and the plants possess a luminous quality: the result looks more like a botanical illustration than a photograph. And since the background is pure white, the subject itself defines the edge of the image as it blends with the page: the only composition is that provided by the structure of the plant.
I started making these pictures – of invertebrates and amphibians as well as plants – to provide material for my Rewilding Childhood project (www.rewildingchildhood.com): simple images that allow children to see what animals and plants actually looked like without the clutter of surrounding vegetation. Picture libraries are full of “cut outs” where the subjects are shown on white but almost without exception, these images are front-lit and shot indoors. In contrast, I decided to shoot all my subjects in the field against a back-lit white Perspex sheet. This allows me not only to show the subject in great detail but also to highlight its translucent qualities.
Here’s some good news: you can make these pictures with a couple of old manual flash guns and two pieces of 3mm opaque white Perspex costing under £15.Really. Since I do a lot of this sort of work, I use a slightly more elaborate toolkit that allows me to work quickly and efficiently. Two Benbo Trekker tripods act as stands for the Lumedyne flash heads, background and front diffuser, themselves supported by Manfrotto clamps and goosenecks. I trigger the flashes from an on-camera Prolinca IR transmitter (although you could use another, very small flash gun to the same effect, more cheaply) so the only cables I need are those that connect the flash heads to their power pack. It is convenient in workshops simply to slip the transmitter on to a student’s camera in order that they can use the set.Assorted reflectors and pieces of FlyWeight (which, incidentally, I use for the front diffuser) hold surrounding vegetation out of the way, where appropriate.
Digital capture, and with it the possibility to refine exposure and lighting balance very precisely, makes this technique feasible. The first requirement is that the background is rendered as pure white (R 255 G 255 B 255). If you do this, it makes the task of compositing (see below) much simpler and saves the need for designers to spend time making (often unsatisfactory) cut-outs. The image can go straight on to a white page. The trick is to judge how far behind the subject the Perspex should be positioned: too close and light spilling forward may overwhelm a pale subject, making it hard to separate from its background. Place it too far behind and it may fail to produce the trans-illumination that is one of the attractive aspects of this approach.
More opaque or darker subjects can tolerate the background just a few centimetres behind them whereas pale plants require greater separation.But don’t forget that even white flowers can be photographed against white, if the background is at the right distance.
Arriving at the right exposure involves careful interpretation of the camera’s histogram – and shooting in RAW. Start with only the background flash switched on. The background should blow out in each channel (so that the highlight warning is blinking) – but only just. You’ll find that even one third of a stop can make the difference between keeping within the histogram limits and banking against the right side (which is what you want). Putting even more light through the background can be problematic in terms of preserving dark tones in the subject. Switch on the front flash now (its output should be lower than the background flash) and check that none of the plant’s highlights are over-exposed. Typically, you’ll end up with a histogram where there are no values in the left quarter and a lot to the right. Don’t worry – you’ll get these dark tones back in the RAW processing. If, however, there is nothing to the left of the mid-point of the histogram there is probably too much light from the front and you are unlikely to recover the whole tonal range at the processing stage. You can reduce the power of the front light by adding a second sheet of Flyweight diffuser or backing it off a little.
Nowadays, I regard the simple white background portrait as just the starting-off point for saying something more interesting about the subject. For example, it is very hard to illustrate the concept of biodiversity in traditional nature photography but by shooting the components of a community separately then compositing them onto a single white canvass we can do just this. Owing to the stylised look of the image, no one is going to imagine that all the plants were growing right beside each other as shown but nevertheless, if each is photographed at the same magnification with the same angle of lighting, the community is fairly represented.
Even if you do not wish to show several species together, you can better illustrate aspects of a single one in a composite – one view perhaps showing the plant face on, another in profile.
This approach also gets round the problem of how to fill a space with a single, slender specimen.
The technique that interests me most at the moment involves recreating the look of early botanical illustrations. For these, the plant must be “ended” before it reaches the edge of the frame (I do this with a special eraser in PhotoShop), then create the look of faded paper using OnOne’s PhotoFrame software. An authentic early 19th Century font completes the look.