Its no surprise that water holds humans in thrall when it is an essential ingredient in our evolutionary past (to say nothing of present and future) and a major constituent of our bodies. In photography water has appeal if it is falling from cliffs, bubbling over stones or has boats (or birds for my co-bloggers!) on it. For ‘mood’ it can be frozen in time by flash or moodily blurred by longer shutter speeds.
At the other end of the scale there are water droplets. The eighteenth-century French painter, Pierre Joseph Redouté, made raindrops on rose petals a trademark in his detailed studies and mist of droplets can impart a definite freshness to photographic subjects. However, it is easy to overdo the effect and it is important to examine how nature does the job with early-morning dew or raindrop before going berserk with an atomizing spray.
Water droplets delineating a spider web provide one of those classic nature subjects that we all try to photograph at some time or other. The secret is to use a narrow depth of field (long focus lens with a wide aperture), so that the background is completely out of focus and does not distract from the delicacy of the web structure. Backlighting from the low-angled morning sun makes the droplets sparkle like jewels and if you get the right angle and you can capture the ‘rainbow’ prismatic effect.
Water droplets as lenses
If we take the time to examine raindrops closely we see tiny images of flowers or of the leaves behind them…outside as I write the drizzle has produced fat lenses in the centres of the few remaining nasturtium leaves magnifying the veins. A droplet acts as a near spherical lens with a very short focal length so you can create two kinds of images: the ‘virtual’ (magnifying glass) image on the leaves and a ‘real’ inverted image formed by the hanging droplets that act as fisheye lenses and pull in all manner of extraneous detail at the edges. So beware.

this was one of a series of flowers of as many colours as I could find
Moving the flower behind the drop changes the size of the inverted image created by the drop: several drops close together will produce a series of images of the same flower. A potential problem, when you get close-up, is that the image in the drop and the grass blade or twig the drop hangs from, are not quite in the same plane. It is essential to have the image in the drop sharp so you have to experiment with the stop down button closing the lens aperture to make best use of the available depth of field.
Getting Those Larger Images – coupled lenses
Several raindrops can be photographed in a row using a macro lens that will give you 1:1 reproduction. But, for shots where the droplet dominates the frame, you have to enter the macro realm with images of 3x magnification and more. The easiest way to do this is by coupling lenses (reversing a 50mm standard lens onto a 150mm lens, for example). For this you need a male to male thread adapter that couples the lenses via their filter threads. The 50mm lens used wide-open acts as an ultra high quality supplementary lens whilst the automatic diaphragms and all lens connections belong to the 150mm lens. This method for creating magnified images has the advantage over bellows and extension tubes of not ‘losing’ light by changing the effective aperture and retaining automatic controls. The magnification achieved is found by dividing the focal length of the prime lens fitted to the camera by the focal length of the additional lens.

this shows the set-up with an Olympus 80mm f/4 macro lens head on a bellows with a twig and cherry blossom - look hard and you will see the droplets
Before you leap at the possibilities of a 24mm lens fitted to a 200mm telephoto (magnification over eight times life size) beware of vignetting – it helps to have lens diameters pretty much the same and not to be too ambitious about magnification. In the field I have used a 150mm macro lens with an old 50mm standard lens or a x2 converter with equal success. Usually, in the studio (a broad term where I am concerned which embraces greenhouse and kitchen table), I use an old Olympus 80mm f/4 macro (a much prized lens) on an Olympus bellows with home made adapters (from T2 mounts or extension tubes) to fit to a Nikon body.

you can see just how wide these droplet lenses are with the clearly visible spars in the greenhouse...fortunately most people do not notice until I point them out.
Forming drops
You can go out on a rainy day looking for droplets that have collected on twig or at leaf tips, but they will seldom be in the right place and the slightest disturbance will dislodge them. It seems easier to take control and construct your own imaging system by placing a twig just a few centimetres in front of a flower, for example. In theory, if you spray or wet the twig, then droplets will form. In practice it is easier to use a dropper and gently squeeze: control is tricky and persistence is essential. If you experiment in a greenhouse then be careful the view angle of the drop will include the greenhouse spars as well – as I know only too well . . .
In film-making, plants are often sprayed with a mixture of one part by volume of glycerine to one of water. This is also a useful mix for creating your own ‘raindrops’, since the higher viscosity and different surface tension compared with pure water create slightly larger, more stable droplets. Also, the mix does not evaporate as easily as water and is better under bright film lights.
Lighting
Any form of artificial lighting is tricky at first because you both have to light the background and simultaneously avoid creating create distracting reflections on the drop surface. If you are using tungsten lamps or sunlight where you can see what is happening, then you could theoretically fit a polarizing filter to the lens front and largely eliminate the reflections.
When you photograph a water droplet using flash, it can create tiny, but perfect, images of the flash tube that you do not see until the image is on screen and the twin bars of a macro flash appear unnatural. The solution is to use s single flash preferably diffused, or a touch of Ye Olde Photoshoppe later…
Daylight, either in the field or with a camera set-up in a conservatory, provides better lighting quality plus some protection against air currents since the drops act as ‘vibration detectors’ quivering with the slightest breeze or movement. For outside work very still days are best. An icicle slowly melting allows water droplets to grow at the tip: pre-focus and await your chance. Early morning dew when insects are waking is another source of striking images in drops.
The diagram shows suggested starting points for lighting. The acute-angle lighting of the drop itself makes it less likely that rays will be reflected from the surface into the lens.

the diagram shows the basic set-up -apologies for my primitive Appleworks graphics
Note
Imaging with water droplets is one of a large number of techniques that was included in Nature Photography Close-up by Paul Harcourt Davies (Amphoto Nov 2003).
© Paul Harcourt Davies