We’ve seen a gradual move away from tungsten video lighting for a number of years now – and for all sorts of reasons. Firstly there’s the ecological issue about using tungsten lights. Burning a metal filament within a gaseous-free glass chamber is not the most efficient way to generate a light source. Most of the energy in this process is used up in creating heat (as tungsten ignites a such high temperatures), which is not only wasteful but also a really unwelcome guest on any film set if you happen to be sat in front of a tungsten lamp for any length of time. The more lamps you use the greater heat is generated which means you either suffer from the heat or have to use more energy by introducing cooling machinery – which in turn creates other unwanted side effects for the sound guy.
The heat issue also means you are limited to how close you can light your subjects – especially if you are filming subjects which are really not that keen on being heated. For instance, I’m sure there are many forms of wildlife who will act very unnaturally under heat-omitting light sources. I’m sure there are even some who would expire under them.
Apart from the high running costs and heat side-effects, Tungsten bulbs are also very delicate – especially when hot. In this state they can also be very dangerous and tend to explode into thousands of tiny molten glass fragments which is why you should never use them without a safety glass in place.
So with all this going against the tungsten light it’s really surprising that they have lasted this long and are in fact still manufactured today. Whilst various alternative light sources have been with us for some time they have been somewhat lacking in performance and have not been able to deliver the same quality of light offered by tungsten lamps. This has certainly changed in recent years though – especially in relation to LED lighting.
The state of LED
LEDs (Light-Emitting Diodes) have been with us since the early 60s and were originally used for all manner of functions such as appliance indicators and other low-intensity applications. Since then this technology has advanced considerably and spread into all manner of light applications and today can be found in everything from car headlights to video displays. This has also resulted in a number of LED constant lighting solutions for video and photography – of varying quality. Whilst LED is a very efficient way to generate light, the light quality is not always the same from one system to another. Generally speaking, the more you spend on your LED lighting the more advanced it will be and will offer a much more accurate colour rendition.
This colour accuracy is known as a CRI (Colour Rendering Index) value which, according to Wikipedia, is a “quantitative measure of the ability of a light source to reproduce the colours of various objects faithfully”.
I don’t intend to research and write about this any further now but a LED lamp with a CRI value of anything above 85 is considered to be “very good” – whereas “very bad” would be at the other end of the scale down at zero. Whilst there are other contributing factors to the quality of light it’s the CRI value that will be often the quoted measure of quality. In video terms anything below 80 will start to cause colour inconsistencies in things like skin tones – especially when there are other light sources falling on the subject.
Lishuai LED508AS Kit
You can spend many, many hundreds of pounds on a single LED light panel so you’d be right to question exactly what you’d get from a Lishuai LED lighting kit which costs a shade under £500 plus VAT for a 2-panel kit (available from ProActive in Hemel Hempstead, Herts). And it’s not just two LED panels you’re getting for this money – it’s two screw-on diffusers, two heavy duty stands, two mains supply units, two battery chargers, four 4400mAh NPF-style batteries and a couple of bags to carry and store it all in.
You’d be in your right mind to expect something quite sub-standard for this kind of money but Lishuai quote them as having a CRI value of just over 80. It’s not perfect admittedly, but in practice the colour rendition is extremely good when compared to the level of investment. Mores the point, your colour rendition is far more likely to be impacted by external light sources, operator error and the colour inconsistencies within the camera itself rather than an LED that’s churning out a CRI value of 80+.
CRI performance aside, there are far more important features and benefits of the Lishuai LED508AS-KIT that have impressed me so far. Each lighting panel measures around 33cm by 17cm and include 508 LEDs – 254 of which are rated at 3200K and 254 at 5600K. A rotary knob on the rear of the unit allows you to dial in your colour temperature from 3200K to 5600K – and anywhere in between. I’ve found this to be extremely useful in mixed lighting situations where it’s enabled me to make a choice between balancing to either depending on the situation. If there’s predominantly external natural light in a room just turn the colour temperature to 5600K. If there’s some really nice artificial lighting then it’s just as easy to balance to that – without the need to add gels or exclude available lights. I’ve also used them outdoors in bright sunlight to add a little fill to an interviewee’s face who was standing in shadow with a brightly lit building behind them. Because of their cool running temperature I could get the lights within a foot or so of the interviewee’s face – positioning the panels almost touching each other to give me a large light source to compete with the strong sunlit background.
The panels are also dimmable (flicker-free) from 10 to 100% which is a really neat feature when trying to create mood and shape to your subject. Lishuai rate the lights at 8500 Lux at 0.5m (falling to 2500 Lux at 1m) so these are not going to light up an entire theatre by any means. However, I’ve found them perfect for lighting interviews and talking-head pieces and on more than one occasion my subjects have been somewhat startled by their brightness.
The units can be either mains or battery powered (30.5w) – which is another really useful feature and demonstrates how much more energy efficient LED lighting is over traditional tungsten lighting. Running the lamps at full power – at a mid colour temperature – will give you around 2.5 hours using both batteries. There’s also a really useful battery power indicator in 25% increments so you know how much longer you have left before a recharge or switching to mains. In my mind though, 2.5 hours is plenty – and if you already have other kit running off the NPF battery system (I have a monitor that will) you can always cross-use these.
Lishuai LED508AS Conclusion
Of all the features mentioned above the one thing that I instantly fell in love with was the lack of heat. I’ve also got an Ianiro 3-head lighting kit and whilst I still use this for some shoots the heat they generate is a serious negative. A lot of my work is based around talking head interviews which are often filmed in the subject’s place of work with limited space and no air temperature control. Once you have a couple of tungsten lamps running in these conditions it doesn’t take long for the videographer/talent relationship to diminish – which in turn doesn’t do anything for their performance and for my end result.
The only negative I have noticed with the lamps, which is not really a negative at all, is that I left the batteries on the lights at one point and also attached the mains supply. This caused the lights to pulse slightly. Once I’d removed the batteries the pulsing stopped instantly – so if you ever experience this you’ll know what to do.
I’m now into my third shoot using these lights and I’ve already started questioning the logic of packing my old tungsten lights into the car. On the last two occasions they’ve not been out of their case at all – relying solely on the Lishuai kit to illuminate. As there’s always been an additional light source at the location (either a window or an artificial source of some kind) I’ve been able to use this in order to create my 3-point lighting for modelling – and used the light’s variable colour temperature according to the source.
You might have guessed from this article that I’m more than chuffed with the Lishuai kit. It’s exceptional value for money and convinced me that my future lighting investments will be in LED. They are cool – in every sense of the word!
Kevin Cook F.Inst.V. (Hon.)
Notes: More information on the Lishuai LED508AS lighting kit is available from www.proav.co.uk