Getting Started With Portable Flash
Portable Flash is battery-powered flash. Battery-powered continuous lighting is also available, but it’s useless outdoors because it doesn’t have anywhere near enough power to compete with sunlight.
The main difference between portable flash and mains powered flash is that although mains powered flash can be used outdoors, either by running extension cables or by plugging the flashes into portable power solutions (basically a battery unit with a power inverter), and although portable flash can also be used indoors, it does make sense to use the right tool for the job.
When it comes to portable flash, the simplest and cheapest solution is to use ordinary flashguns, and they’re great for adding a little fill light to your shots, and for use when it’s dark or very nearly dark – but one of their problems is lack of power, because they simply don’t have anywhere near enough power to create light in bright conditions, all that they can do is to add to the light that’s already there. The only workaround is to cobble several flashguns together, to increase the power, and this does work to a limited extent but although it does help with the power limitations, it’s a complicated and expensive way of doing it and several flashguns joined together and firing together are still just several individual flashguns – adapters are available which allow up to 3 flashguns to fit inside a softbox, but that’s about all that you can do to control the quality of the light. And, if you’re using just one flashgun in a softbox, you’ll be limited to small softboxes of up to around 60 x 60cm, because flashguns have a fixed reflector that prevents their light from bouncing off of the walls of the softbox and producing even lighting without hotspots.
Which make should you go for?
Well, it’s always tempting to go for the same brand as your camera, and there are definite advantages in this, especially in terms of both features and build quality, and it’s good to get a warranty too, but this can be a very expensive option and a lot of people now buy much cheaper copies from Ebay, Amazon etc. For many people, this makes perfect sense because of the massive cost savings, but you should balance these savings against the absence of a worthwhile warranty. Basically, if you view these flashguns as disposable and can afford to replace them when they fail, then they can be a very good choice.
So, the next step up in the portable lighting world is to use a more powerful unit, such as our Atom 180, which is much more powerful than an ordinary flashgun, or our Atom 360, which is twice as powerful again. But it isn’t all about power, the biggest single advantage of the Atom is that the reflector is removable, which means that not only will it work properly in a softbox, it can also be fitted with our High Intensity Reflector, which increases the effective power by at least 2 1/2 stops!
With this type of setup, you’ll be able to control the lighting as well as to just add fill light, and photography is all about creating and controlling light.
The Atom is a big step up from flashguns, but does it have enough power for all situations? Not really. If you want to have full control in all lighting situations then you need a lot more power.
How much power do you need? There’s no definitive answer to that, because it will depend on a couple of factors:
- How bright is the sunlight? In really bright sunlight, with the flash really close to the subject, 600Ws will normally produce enough power to dominate and control the lighting, nothing less than 600Ws will do the job.
- How far away will your lights be from your subject? The Inverse Square Law can cause problems here, because every time you double the distance from light to subject, you will lose 3/4 of the lighting power, and with wide scenes you have a simple choice – either use very powerful lighting and get the lights far enough away to be out of shot, or spend a lot of time in post production, cloning out the lights. Of course, the Inverse Square Law applies to indoor photography too, but when we’re shooting indoors we don’t have to worry about flash power too much, because the level of ambient light is always very low, which means that there is little or no ambient light to overpower.
- Which modifiers will you use? Again, if you’re using a softbox then there will be a big loss of lighting power. And frankly, softboxes can be pretty limited outdoors. One of their limitations is that they eat power, unless you can get them really close to your subject, and another limitation is that they act just like a sail when it’s windy, and can easily blow over and wreck your expensive equipment! Our new range of RedLine Pro softboxes helps with this problem because they have tie-down rings on them, which are used to secure the softbox to something solid (tree, vehicle, tent peg etc) using strong but lightweight paracord. If you don’t have one of our softboxes, you can tie off the lighting stand instead, with the paracord fitted as high on the lighting stand as possible. Putting weights on the lighting stand can help to a degree, but it’s nowhere near as secure as tying the equipment down:)
So, consider our Safari 2 Portable Lighting System.
It’s available in a choice of a single head, 600Ws unit, or a twin unit combination with two of everything and 1200Ws. Of course, the Safari 2, like all other tools, isn’t always going to be the best solution simply because, although compared to competitive units it’s reasonably priced, small and lightweight, it’s bigger and heavier than a hotshoe flashgun or our Atom System. It’s main advantage is that it has the power you need for just about any situation. The Safari 2 is a mature, proven system but there are alternatives available from the far east, which have impressive specifications – but you should consider just how important things like TTL, HSS (high speed sync) will be to you, because unless you actually need these features you will just spend a lot of money buying equipment that has far more potential to go wrong, and that you won’t be able to get repaired, simply because there is no real infrastructure in place to provide customer service, once the item is out of warranty, and, if you buy from Ebay or Amazon, there is usually no real warranty anyway.
TTL can in fact be useful, but it uses a kind of “fuzzy logic” algorithm that guarantees that your flash exposure will never be totally wrong, and people very quickly learn that they can get the flash exposure absolutely right if they set the power manually…
HSS can be very useful, but it eats power and so it’s only really useful if you have a real need to freeze action. The other main benefit of HSS is that it allows you to control the effect of ambient light, which can be very useful, but you can control ambient light just as effectively by using a neutral density filter over your camera lens, which is a cheap, simple way of doing the same thing. The photo on the left illustrates this, please click here if you’d like to know the full details, but basically this shot was taken on the brightest and hottest day of the year and we had more light than we wanted before we added the Safari flash, so we fitted a 3-stop (0.9) neutral density filter to the camera lens, which allowed us to open up the lens and blur the background. This effectively reduced the ISO to just 12.5.
I needed to do this because I was going to overpower the sun by about 2 stops to draw more attention to the subject , and the neutral density filter now gave me a nominal aperture of f/2.8 which I would later adjust if necessary, once the flash had been added.
This is the standard method of allowing large-ish apertures to be used in bright sunlight.
Triggering your flash
If you’re using camera-brand flashguns, the major manufacturers each have their own proprietary system for triggering and controlling the flash off camera, but these systems can be complicated, and most people, regardless of whether they’re using flashguns or full-blown portable lighting systems, use radio triggers instead. With many of these systems, including our Atom and Safari, the radio trigger also acts as a fully featured remote control system, which can be very useful. If this isn’t available to you then you can usually use any radio trigger, nearly all of the ones now available are both cheap and reliable.
Using a flash as a slave
Many flashes have a slave cell that responds when it sees another flash, and fires. In theory that’s a useful feature, and in practice it can be reliable when used in a studio setting, but it cannot be relied upon in bright, daylight lighting conditions, so if you’re using more than one flash it makes sense to connect a radio receiver to each. The reason for this is that radio signals are reliable but optical slaves can only work in dull lighting conditions, where the flash is much brighter than the ambient lighting.