Researchers at the Royal Belgian Institute of Natural Sciences (RBINS) have constructed a focus stacking set-up made of consumer grade products with better end results than high-end solutions and for a tenth of the price of current systems. Because of the operational ease, speed and the low cost of the system, it is ideal for mass digitisation programmes involving type specimens. The study was published in the open-access journal ZooKeys.
Whether enthusiasts or scientists, many struggle to take high quality pictures of the tiny animals of the micro world. When they eventually succeed in their effort, it is clear that it is rare that the entire subject is in focus.
However, a solution exists to overcome the problem of small focussed area in macro photography: focus stacking. In this technique many pictures are shot with different focus ranges. The entire set of pictures will be pieced together to form one image with the entire subject in focus. This is nothing innovative, as the technique has been around for several years. Many microscope companies offer solutions to produce these sets of pictures of any subject at the other end of the lens. The downside is that these set-ups are only available at high prices.
The set-up by Jonathan Brecko, who is currently working as a scientist for our Institute and for the Royal Museum of Central Africa (RMCA), produces the same or even better results than the high-end solutions tested in the manuscript, and for only a fraction of the cost (8 to 10 times less).
The set-up is fairly easy to control and consists of consumer grade products, making it easy to replace when needed. The central idea of the set-up is to place both the subject and the light system within a simple kitchen cupboard.
Thanks to the low noise and high resolution of the 65 mm macro photo lens used for the project and the lighting system placed within the closet, it is fairly straightforward to produce highly detailed, quality pictures. Even specimens within alcohol can be photographed with ease.
This set-up can be an important tool to aid digitisation programs, because the highly detailed pictures can in some cases replace the need to ship or send very fragile specimens for study in all kinds of disciplines. At the moment the set-up is used in the digitisation programs involving type specimens at RBINS and RMCA.
Click the image above for more high res. pictures of insects and invertebrates taken with the low-budget focus stacking system.
This research has been conducted in the context of the Agora 3D Project (AG/LL/164) and DIGIT03 funded by the federal Belgian Science Policy (BELSPO) and the European FP7 SYNTHESYS 3 program.