How to dramatically improve the quality of light from external flashguns for better and more life-like results
The biggest weakness of built-in and auxiliary flashguns is that the quality of light they emit is pretty unimpressive. Because the flash is a high-intensity light source that originates from a relatively small area close to the lens, it yields flat, uneven lighting that creates deep, hard-edged shadows. It can also eradicate fine textures and contours, bleach out skin tones and cause red-eye – all of which makes for particularly disastrous portrait, wildlife, macro and interior shots. Larger flash heads aren’t quite as bad because they spread light over a slightly wider area, but the results are still unsatisfactorily harsh.
This type of lighting, which hits your subject straight from the flashgun, is known as direct flash. Although direct flash usually looks artificial and ugly, it can generate terrific effects when used shrewdly. Most of the time, however you’ll need to minimise the downsides.
Take it off!
The key to improving the quality and flexibility of flashgun lighting is to enlarge and soften the light source and fire it at the subject from a more natural direction. To accomplish this you need to completely separate from your camera using a hotshoe adaptor and sync cord. This will enable you to position your flashgun far more suitably and creatively. It will also give your subject a sense of depth and eliminate red-eye.
Nikon and Canon both make all-in-one off –camera cords for around £50 that preserve full TTL balanced flash metering and power output. Some cameras require you to buy two adaptors – one for the hotshoe and one for the base of the flashgun – and a cable to connect them.
If you prefer to keep your hands free while you shoot and you don’t mind looking more conspicuous, you can buy a flash bracket that connects to your camera’s tripod socket and angles the flash unit permanently to one side. Large hammerhead flash units, used for illuminating larger subjects like buildings, are commonly used in conjunction with a bracket.
Ceiling good
Of course, simply taking the flash off-camera doesn’t stop the lighting fom looking harsh and artificial – it still needs enlarging and softening. There are several ways of doing this, and one fo the most effective is to bounce the flash. This is easy if your flashgun allows you to tilt the head upwards and swivel it around the horizontal axis.
The idea is that you bounce the flash off a reflector, wall, ceiling, or even a mirror – spreading the light over a much larger area and effectively increasing the size of the light source. This lightens dark shadows and produces softer, smoother and more natural lighting than direct flash. For the best results, tilt the flash head up to at least 60 degrees . The downside is that subjects can look somewhat flat and lack that ‘sparkle’.
Bouncing flash can also produce unwanted shadows underneath a subject, which in the case of a portrait accentuates eye bags and creates shadows under the nose and chin. It also significantly reduces flash power, which typically translates to a light loss of two to three stops.
As long as the flash sensor’s still pointed towards the subject a TTL flashgun will automatically amplify it’s output to compensate for this but if it can’t meet the new requirements you must increase your aperture, boost your ISO and / or move in closer to your subject. If you’re using a manual flashgun you’ll need to increase your exposure accordingly. Another important consideration when bouncing flash is that the surface you bounce off must be a neutral white, otherwise your subject will end up with an unnatural colour cast.
Show your cards
Better flashguns have a white bounce card built into the flash head to reflect some light directly onto the subject when the unit is tilted up into a bounce position. Bounce cards are a great way to add a vibrant catchlight to a subject's eyes and to fill-in any resulting shadows - for the most effective results, tilt the flash head up to 90 degrees.
Some advanced flashguns feature dual flashtubes instead - firing a weaker burst directly at the subject to fill in shadows and add a catchlight while the main flash is bounced upwards. If your flashgun doesn't feature a bounce card or dual flashtube, try using a rubber band to secure a piece of white card around the back of the flash head to reflect some light forward.
Conventional bounce flash won't always be practical - you might be working outdoors. And if you're indoors the ceiling / walls might be too distant or the wrong colour. One solution is to buy a mini flash reflector that clips around the flash tube and bounces the light forwards, softening it with minimum loss of light. Personally, I would recommend a Gary Fong Lightsphere.
If your flashgun is a non-tilt model, taking it off-camera will allow you to bounce the flash in any direction. An off-camera flashgun can also be reversed, attached to a shoe adaptor and studio brolly stand and fired into a reflector or diffuser brolly, thereby turning it into a respectable studion light.
Diffuse the situation
A flash diffuser is a good alternative to bounce flash and works in a similar way by spreading out hard, directional light into a larger omni-directional source. This minimises red-eye, weakens shadows and creates softer, more flattering lighting. Taking diffused flash off-camera allows you to create even more natural results. You can buy various types of diffusers for external flashguns. High-end flashguns often ship with a transluscent diffusion dome which looks a bit like a plastic ice -cream carton and fits snugly over the flash head. Sto-Fen Omni-Bounce diffusers are made for most flashguns.
To create a more powerful diffusion effect you need a miniature softbox, such as LumiQuest's Softbox of Mini Softbox. Lastolite also makes a mini Micro Apollo softbox in different sizes. For the ultimate in soft, shadow-free lighting, combine off-camera bounce flash with a diffuser, adding a wide-angle adaptor for even greater diffusion. This method's great for close-ups and portrait work, but because diffusers also reduce flash output by up to two stops, you could be looking at a light loss of five stops in total. Products like the LumiQuest Ultrasoft overcome this problem by combining a mini reflector an diffuser in one completely enclosed modifier that keeps light loss to just two stops.
Look, no wires!
Using two or more flashguns will extend your lighting options considerably. To avoid nasty multiple flash exposure calculations and cumbersome cord connections, the simplest, most effective way to connect several flashguns is via a wireless TTL multi-flash system. Nikon and Canon's latest wireless TTL flash systems use up to two channels that can be controlled independantly with over a dozen flashguns operating within each channel. The 'slave' units can be controlled by a 'master' flash unit attached to the shoe fitting on the camera or alternatively a specialist infra-red master unit (Canon Speedlite Transmitter ST-E2).
Being able to position several units up to 12 metres from the camera has many benefits. Most importantly, you've got the freedom to create natural looking lighting that eliminates shadows and emphasises the subject's form, texture, tones and colours - essential for commercial photography. You can also illuminate dark backgrounds, highlight secondary elements, cast coloured lighting - the possibilities are practically endless. Usually, only top-of-the-range flashguns have the ability to control multiple flashguns in a wireless TTL setup. If your flashgun isn't wireless-enabled, but features a PC cord connection, you can create a cheap and cheerful, non-TTL wireless system by attaching a PC slave unit to it. This sticks to the top of the flashgun and plugs into the PC socket, allowing the flash to be triggered wirelessly, either by your camera's built-in flash or an on-camera auxilliary flashgun.
This article shows the quality and variety of techniques that customers benefit from as part of our commercial photography and architectural photography service. Call now to discuss your requirements and timescales on 079101 68536.
