It appears I need to do more research on LED systems. I did not realise they had limitations.
Everything has its limitations, some of the problems of (any) continuous lighting are set out here
https://www.talkphotography.co.uk/threads/led-studio-flash.718904/
People often think that continuous lighting is "better" than flash because of the "what-you-see-is-what-you-get" perceived advantage. And it really doesn't help when
dishonest ignorant sellers mis-describe them, exaggerating the power, often stating false colour rendition figures and so on. They're great for video, where continuous lighting is essential and where the interest created by moving subjects masks the faults, and also great for my off-road farm car, tractors and other plant that needs incredibly bright lights, but a very poor choice for still photography.
Here's a short extract from one of my books, which may help.
Which type of artificial light?
Photographic lighting is about controlling the light. Up to a point, we can control daylight, and I will cover this later in the book, but our control of daylight is very limited so we usually use some kind of artificial light instead.
This subject seems complicated, but it’s quite simple – we need the type of light that produces the best results for the type of photography that we do, so all that we need to do is to base our buying decisions on our needs, and ignore all the claims made by the people who sell the equipment…
There are only 2 main types of photographic lighting, continuous light and flash, and each of these types then divides and sub-divides into sub-types.
Continuous lighting is light that is on all of the time, and
flash is light that is there only when you need it. And there is a third type of light, ambient light. This is the light that happens to be there but which we haven’t created ourselves.
Continuous lighting
A lot of people start off with continuous lighting because they think that it’s easier to use than flash, and it’s also a lot cheaper. Continuous lighting is perfect for video but this doesn’t mean that it’s the right choice for still photography. It’s cheap for a reason!
Having said that, there are a small number of highly skilled photographers who use continuous lighting, for specific purposes, but they use it because it suits their specific needs, and they mostly use extremely large, powerful and expensive lights.
It does have one real advantage, WYSIWYG (What you see is what you get) and you don’t really get that even with the very best studio flash lighting but it has real disadvantages too. There are a few different types of continuous lighting.
Hot lights
These are really obsolete now, but I mention them for the sake of completeness. Hot lights are basically filament lamps, they produce a lot of heat and a surprisingly low amount of light because about 2/3rds of the energy used turns into heat, not light. Photographing some still life subjects with hot lights can damage them, or even set fire to them, and photographing people with them can be a form of torture for the people!
Fluorescent lights
Technology has moved on, and hot lights were quickly replaced in popularity by fluorescent lamps -not the strip lights that you still see in some offices and factories, but by coiled lights that fit into fairly small lamp holders and which are claimed to be perfect for all sorts of photography. Their big advantage is the low cost, especially if you buy the dirt-cheap ones online, but you need to know about their limitations.
- They are physically fairly large, and because of this, they can only be used with lighting Umbrellas or with the supplied softbox (more of which later). Because of their large size, they can’t be used with any of the more precise lighting tools that you will need to use.
- You can’t reduce the power, because they have no adjustment and are either on or off. If the lights have several individual fluorescent lamps then you can turn one or more off to get some kind of power adjustment, but that’s about it, and it isn’t enough. You can also change the effective power by moving them closer to or further away from your subject, but that’s always a bad idea because changing the distance also changes the quality of the light – the right distance is always the distance that produces the right quality of light, not the right quantity of light.
- They don’t produce true white light. I’m not talking here about the colour temperature of the light, which can be adjusted either in-camera or in Photoshop, what I’m talking about is something called CRI (the Colour Rendition Index). Daylight, flash and filament lights have a perfect CRI of 100, which means that all colours of the spectrum are there, which means that all colours are reproduced as accurately as possible. The very best photographic fluorescent lamps that I’ve personally tested have a claimed CRI or around 95 and a real CRI of around 90. They are known as discontinuous spectrum lights, which means that the magenta colour is missing from the light that they create. In practice, the reds in your photos will photograph as orange, orange will photograph as yellow and yellow will photograph as magnolia – and no, you can’t really correct that in Photoshop. The cheapest of these lights often have a CRI of around 60, they are totally unusable for photography. Usually, their online sellers either don’t mention the CRI or give a false figure.
- They aren’t powerful enough. They sort of are, if they are the only light source in your studio, because you can, in effect, increase their effective power by increasing the ISO setting on your camera, but you will have to eliminate ambient light by making sure that no daylight can enter the room and that all room lighting is switched off, otherwise you will lose lighting control and will also end up with different lighting with different colours. And, if you want to use them outdoors you will have to wait until it gets dark, because they have far less power than daylight and are totally unusable in bright lighting.
- They are uncomfortably bright and will dazzle your subjects. This seems to contradict my statement that they aren’t powerful enough, but although they aren’t very bright they seem to be very bright to the poor victim who has them shining in their eyes.
LED lights
fluorescent lamps are now being replaced by LED lighting, and LED lights do offer a number of advantages.
- They are (or can be) more powerful
- They are often fully adjustable for power
- They are tiny, compared with fluorescent lamps, and some of them – but not the flat panel variety – can work well with most (not all) lighting modifiers
- On many, the colour temperature (but not the CRI) can be adjusted to suit, although this does increase the price and also reduces the effective power.
But, they have exactly the same disadvantages that fluorescent lamps have, as set out above. I have to say that, as long as 8 years ago, I visited a factory in China where they made extremely high quality LED lights, designed for the movie industry. Most of us would need to sell our house to buy just a couple of these terrific LED lights, but the fact that lights of this quality and performance exist (at a price) indicates that much better LED lighting
is on its way and no doubt will become available at reasonable prices in the future. Right now though, most of the LED lights sold for photography are nowhere near the standard that I believe that we need them to be.
