Photography News | Issue 35 | absolutephoto.com
Macro lighting ratios
Ring flashes and macro lighting
4:1 Lighting ratio
1:0 Lighting ratio
With most macro flashes you can control the power across hemispheres. This is calculated as a ratio, with the overall power setting being split between the two sides. You can put all the power in from one direction, or the other (the 1:0 and 0:1 examples right), or have a blend of the two; whichever best suits the subject. Splitting the light is helpful as, with both sides at an equal ratio, the lighting can be quite flat due to the way it wraps around the lens, therefore providing very little shadow. In the main image I decided to use a fairly strong 8:1 ratio pushing the light in from the left, the space into which the flower was facing, much like you might with a portrait.
Thanks to their design, with the light source wrapped around the lens, ring flashes and other macro lighting accessories can provide the perfectly even illumination for macro subjects. The light sits so close that there’s nothing to block it and with the effect of the light greater than when at a distance, little is wasted, so very small apertures can be used if desired. This wraparound light source also gives very soft, almost shadowless results because, when used with subjects that sit within the circle, light is striking them from all angles at once. Such accessories come in many forms; in this technique we used Nissin’s MF18 Macro Flash at around £300, but there are plenty other flash-based examples such as the Metz 15 MS-1 Wireless Macro Flash (£250), Canon MR-14EX II Macrolite (£450) and Nikon R1 Close-Up Speedlight Remote (£415), which uses two small, independently angled flash heads next to the lens, instead of a tube design. If you’d rather use continuous light, look at the Aputure Amaran Halo LED (£50) and the Interfit 48mm fluorescent ring light (£86). There are also adapters, which push the light from a regular speedlight into a ring to get the same effect, like the The Orbis Ring Flash (£150) and the Rayflash (£90).
1:4 Lighting ratio
0:1 Lighting ratio
1:1 Lighting ratio
Exposure settings When setting the exposure it’s time to consider how you want the image to look; for example do you want to mix the flash with the ambient light in a way that looks quite natural, or make the most of the faster shutter speed, which will likely mean underexposing the background a little. The latter option is very handy if you have a cluttered or confusing background as it will turn prettymuch everything behind the flash- lit subject dark. However, for this wild-flower subject, I went towards the former. With the camera in manual mode (M), I used the exposure bar on the top-plate LCD (you’ll find similar on your live view screen or in the viewfinder) to assess the shutter speed required at my chosen aperture of f/11 and ISO 400. With the subject in shade the metered shutter speed was an unusable 1/8sec and a quick test exposure showed lots of unwanted subject movement. Theidealthinghere,wouldbetoincreasethe shutter speed to somewhere near the camera’s sync speed, but this will lose all of the ambient light, so a compromise was needed. I raised the shutter speed to 1/30sec, and a second test shot showed a slightly underexposed but much sharper subject. Finally, I set the tripod- mounted camera to self timer mode so that I could trigger the shutter without transmitting any shake to the image. Flash settings Now it was time to bring in the flash. I used the Nissin MF18 in TTL mode, which works with the manual exposure mode thanks to a preflash that meters the amount of light required, but there’s nothing stopping you from shooting in manual flash. The TTL mode gave a good starting point, but the subject was still a little underexposed, so I used the MF18’s flash exposure compensation function, finally settling on +2.0EV. If you’re shooting in manual flash mode, it’s just as easy to raise or lower the power slightly to get the look you want, but instead of, for example, using +2.0 to add the power, you’ll likely be using a fraction, for instance going from 1/64 to 1/16. Like many macro flash systems, the MF18 has its output split into hemispheres so you can alter the output to look less perfectly
balanced and therefore more natural, which is especially useful if the subject has water droplets on it as mine did (a complete circle of light reflected in themcan look odd). Changing the output ratio, I pushed more light from the side the flower was facing, so that it appeared to be turning into the light. I left a little light on one side though, to keep some illumination in the shadows, ending up with a ratio where the output was split 8:1. Most ring lights can also be rotated, so you can light from the top, side, or underneath if desired, but I was happy with a slightly angled left-right split. Add some backlighting One thing I did feel lacking though was some backlighting on the flower to pick out the delicate edges of its petals. To get this you can set up in direct sunlight, and position the subject facing away from it, but due to weather and subject location that’s not always possible. Instead I positioned a second light off to the back of the flower – a Nissin Di700A (reviewed this issue), placing it on a low-level lighting stand and directing it back towards the lens. To trigger the light I set it to slave mode, so it would fire along with the ring light and controlled the powermanually. After checking the effect via a few test shots I settled on a manual power setting of 1/64, which gave just enough of a highlight to the edges; higher settings looked more like a strong sun, but that took too much attention away from the subtle details of the flower. hemispheres so you can alter the output to look less perfectly balanced and more natural... Like many macro flash systems, the MF18 has its output split into
Above I used a second flash as a backlight – a Nissin Di700A, set to Slave mode, so it would be triggered by the light of the ring- flash when it fired. Below Some attention to lighting means you can shoot good macro pics anywhere.
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