If there is one really inexpensive accessory that can truly transform your photography, then it’s the humble lighting gel. A single piece of coloured plastic may be featherweight on the cashflow but can be a heavy-hitter when it comes to giving a bold new look to your images. When used with flash or another artificial light source, the gel can add loads of drama, change the mood of scene, saturate colours and much more. From more serious and technical changes such as colour correction to far more funky results, a set of gels can work wonders – as long as you know how, why and when to use them.
Let’s start with the equipment itself. Gels sold for photography are thin pieces of sheet plastic that are commercially made in a whole rainbow of colours. For years, amateurs used sweet wrappers or bits of cellophane as makeshift gels. But with huge sheets of proper photographic gel costing not much more than small change, then it makes sense to buy the real stuff.
They are available in hundreds of colours that you can select from each manufacturer’s catalogue. You then cut them up with scissors into whatever size you need, and if the gel gets too damaged then just throw out the old bits and cut up some more. Gel sheets are typically half a metre wide by a metre long or more, so you’ll usually have plenty to play with and they last for years –especially if you store them well. Some photographers store them in tight rolls; others cut them up into sheets and file them in folders, which help with organisation too. So you can always see how many you have and in what colours. And it can be a good idea to buddy-up with fellow photographers, mutually agree to buy gels in different colours then cut them up and mix-and-match to ensure you have a wider choice.
If money really is an issue, instead of photographic gels you could buy sheets of coloured cellophane from hobby stores as it’ll be cheaper. The range of colours isn’t as wide and the material is much thinner, though. This makes them harder to use as they are so flimsy, and also means they don’t alter the colour of light as effectively. You often end up double or triple-folding cheap cellophane to get the same effect so it’s not really recommended although it can work in a push.
The job of the gel is to go between the light source and the subject, which means the light itself takes on the colour of the gel. Put a green gel in front of a flash and you get a pool of green-coloured light, for example, so you can create pools or washes of coloured light. It’s as simple as that.
However, actually fixing the gel in front of the light source can be an issue. Some studio lighting systems offer gel holder kits. These usually have some sort of template for the gel itself, so you just cut up what you need out of the sheets you’ve bought and slide them into the holder. Similarly, some off-camera flash accessories for hotshoe flashguns, such as the Lastolite Strobo system, have a purpose-built gel holder that does a similar job to a studio-style gel holder, except it’s far smaller. Cut up the gel sheets into the right size, albeit very small pieces, and you’re away. The Strobo actually comes with a set of coloured gels anyway.
That’s OK if you want to keep things to basic modifiers. But if you want to gel your lights and use them with accessories like softboxes, umbrellas, beauty dishes or honeycomb grids, then you may have to get creative. The Strobo works with gels and grids, or gels and snoots, for example. But it’s the exception rather than the rule.
Some grip manufacturers that deal mainly in the movie industry, such as Avenger, sell gel holder frames in a range of sizes that can be used in conjunction with other light modifiers. But for strict photographic use, these are relatively rare. That’s why a lot of the time, it takes a bit of DIY ingenuity to use gels with other modifiers. This usually takes the form of cutting the gel into bigger sheets, then using a variety of crocodile clips, gaffer tape or rubber bands to fix the gel as best you can. Inside a softbox, for example, a gel sheet can be cut to the same shape as the softbox and fastened on using crocodile clips or small pony clamps. This can be on the outer edge of the softbox, or actually inside using a smaller size gel. As long as the light goes through the gel before hitting the subject, it will work. But beware – putting sheets of gel inside light modifiers and near to modelling lights can increase the heat hugely. Always be aware of the potential of excessive heat, keep your eyes peeled and be aware of any smell of burning. You have to think safety first and if in any doubt, just don’t do it. And always have a correctly-rated fire extinguisher to hand anyway – as you always should have in a studio environment – in case something goes wrong. Better safe than sorry.
For this very reason, it’s far more tricky to use gels with continuous lights. It can be done – and has for years in the film industry where gelling lights is the norm. It’s best to use gels with cold-running lights such as LEDs or Kinoflos instead of hot lights like tungstens or HMIs. It’s all possible, of course, but you have to be far more careful of the potential heat issues and ensure you are using the proper heat-resistant light modifiers and gels. Bits of gaffer tape won’t cut the mustard here.
With your gel in place over your light source, the light output takes on the colour of the gel. If every light source has the same colour gel, then adjusting the power of the light just adjusts the intensity of the light output. And you can adjust your camera settings to get the exposure right. Either use a light meter or take a test shot and check the histogram or, preferably both. Then either change your camera’s ISO, shutter speed or aperture to get the required exposure. Or alternatively leave the camera settings alone and alter the power of the lights. Gels, especially darker coloured ones, do cut down the intensity of the light source so you have to be aware that you may not have as much light to play with as normal. You might have to increase ISO, for example.
If the light sources don’t have the same coloured gels as each other, then this is when things start to get more interesting. Altering the power of your light source not only affects the brightness of the output but how deep the colour is, relative to other light sources. And if you are washing this light up against a background, for example, then the colour and brightness of the background will affect the image significantly. A dark grey textured background illuminated with a red gel would look much darker and richer than a bright, white shiny background when illuminated with the same gel. So experimentation and constantly checking the results on the camera’s LCD can be key in getting the results you really want.
Once you’ve got your location, subject, lights and gels ready to go, then the fun can really begin. The origins of using gels in photography were largely for technical use in colour balancing – to make sure all light sources were the same colour temperature, for example. So if a room were illuminated predominantly by daylight, apart from one dark corner that was lit by a typical household tungsten bulb, then that part of the room would look very orange and unnatural in comparison. So by using a blue gel over the tungsten bulb, the colour of that light would be made the same as daylight and the room would look naturally lit. So that’s a conventional, technical use of a correction gel that is used a lot on commercial shoots every day.
Enhancing the ambient light
But there’s far more to gels than simple colour-correction, although it is a good place to start to get creative. Using predominantly natural light enhanced with just one flash with a coloured gel as an accent can subtly improve a scene. For example, if you are photographing an interior that’s lit with daylight streaming in through windows, but there are artificial lights within the scene, then by hiding with a Manfrotto Justin Spring a small, radio-triggered flash with a warming gel inside the lamp can give it a nice natural glow.
And compared to just turning the light itself on, using a flash inside means you can easily alter how bright the light fitting appears relative to the rest of the scene – impossible to do any other way apart from using lots of layers and technical work in Photoshop.
A single flash with a warming gel can also be used to add a bit of fake low sunshine to an outdoor scene – especially when it’s used to enhance some real low sun that’s just not quite bright enough. For our shot of a model by a pond at sunset, the main light on the subject is a flash in a softbox. But just out of the frame on the left and behind the model, roughly the same direction as the sun is coming from, is a flash fitted with a warming gel. This boosts what’s already there to give a golden glow of rim light around our blonde subject, and doesn’t look too fake. And by having the flash almost encroach into the edge of the frame, it’s even caused a little bit of flare too.
As the sun sets even lower, a key technique is to use a warm gel – such as a CTO orange – as the main light on your subject, ideally in a modifier like a softbox or umbrella to keep the light diffuse and flattering. If the main light on your subject were just from this light, then the resulting image would be very orange and unnatural – because you’ve essentially turned your daylight-balanced flash into a tungsten-coloured light. So by changing the white balance on your camera to tungsten, the light on the subject then registers as natural. But anywhere in the frame that isn’t lit by your main flash – the background or other subjects lit by ungelled flashes, for example -then this goes a much cooler, blue colour. The sky particularly takes on a much more vivid blue. It’s a great way of creating shots with a more pleasing and brighter blue sky than may have naturally have been there in the first place.
And the same technique is used on our bride who is lit by a CTO orange-gelled flash with a honeycomb grid to control the pool of light.
By setting the white balance to tungsten, it means her face is lit by natural-coloured light. But where this light hasn’t registered, and the illumination is solely by the ambient light, then the image takes on a very cool look, especially noticeable in the shadows. And this coolness also matches the blue flowers around the outside of the door for a striking and very different image.
Using a warm-gelled flash can also work indoors when there is a significant amount of light registered through windows, doors or a skylight, for example.
By using our favourite CTO-gelled light and a honeycomb grid with the white balance set to tungsten, the light on our model has a very different colour and feel to it than the cooler light in the rest of the image. This mix of colours can give a slightly uncomfortable feel to the image, partly echoed in the slightly defensive pose and attitude of the model.
Go bright for bold results on location
While CTO and CTB colour correction gels – colour temperature orange and blue – are great for precise colour matching, images can get a bit more wild when you start to use bolder, primary colours. And it can work especially well on location where the normal ambient lighting on the subject can contrast against a wash of colour.
This can be a huge and obviously significant contrast, or can be reasonably subtle such as in the case of our shot of TV presenter James May with his motorbike collection.
The main flashes illuminating the man himself and the three bikes nearest the camera are totally ungelled, so they mix in seamlessly with the ambient lighting of a typically overcast London day.
But hidden on a Manfrotto Justin Clamp behind the subject are a couple of small flashguns with light blue gels on, aimed at the black bike in the background and also towards the inside of the garage. What these flashes do is give a subtle blue tone to the shadow areas, which harmonise with the overall desaturated tone of the image. This whole look and feel was previsualised before the shoot.
Using a blue-gelled flashgun to provide a bold rim light but also colour midtone areas was the technique used in the shots of an Olympic wrestler in his training gym.
The main light on the subject is an ungelled flashgun into a Lastolite Ezybox Hotshoe, and hence gives a natural colour balance to what is the image’s key light. The rear light, another small flashgun fitted with a light blue Strobo gel, is directly behind the subject and aimed at the camera. This gives a rim of light around the subject, creates distinct shadows of the wrestler’s legs towards the camera and gives a slight blue tint to the midtones that matches with the gym’s blue décor.
But for even more dramatic results, bold-coloured gels and more powerful lights to overpower the ambient light is called for. Still using the combination of un ungelled key light in a Lastolite Ezybox Hotshoe and a rear light of a bright coloured gel, by increasing the output of the flashes to near their maximum allows the man-made light to totally overpower the ambient light and the colours of the gels really shine through. Using this technique, bright red
or bright blue
gels can really give some deep, saturated colour to the background while the light on the model still looks natural to keep skin tones accurate. The results might not be natural looking, but they can really grab the attention of the viewer.
When the ambient light in a location is so low that it hardly registers, then it’s even easier to get more funky with your coloured gels as the light doesn’t have any ambient to fight against.
So our shot of a performer in front of his dimly-lit stage is illuminated by just three small flashes.
The first two are ungelled, with one to the far right of the camera aimed at the subject’s face. This flash is shot through a honeycomb grid to create a beam of light and prevent it illuminating the stage behind the subject. A second flash is directly behind him, aimed towards the camera, to give rim lighting to his hair and clothes. And the final light, a flash fitted with a red gel to look like stage lighting, is aimed at the background from the right of the frame. It’s all about creating an atmosphere.
And there’s loads of atmosphere in this complex shot of our dirt bike rider, taken at dusk in a disused sand quarry.
The key lights on the subject are two large and powerful, battery-powered Elinchrom Ranger flashes fitted with honeycomb grids to control the spill of light. But hidden in the sand around the outside of the corner are four more lights, two fitted with red and two with blue gels, aimed back towards the camera position to rim light the biker. At the last minute before the motorbike rides into the frame, an assistant sprints in front of these lights with a battery-powered smoke machine. Some of the flash heads were retouched out of the final shot, but it’s the combination of coloured gels and smoke that really give this shot its unique look and feel.
Gels in the studio
For the ultimate in controlled lighting, and where gels can really come into play, is in a studio environment. Whether it’s a well-equipped pro studio or just a room at home with a couple of basic flashguns, the theory is the same and the results can be equally as creative. It’s not about spending loads on kit, it’s about using what you have to best effect.
With a simple two-light set-up, you can use gels to really change the look of a portrait, for example. It’s relatively easy to use a single softbox to illuminate the subject and a second flash fitted with a gel to illuminate the plain-coloured background wall.
Just make sure the key light on the subject doesn’t spill too much into the background or else it will kill the effect of the coloured gel. You can do this by using a grid on your main light, and ideally moving the subject far enough away from the background so the light doesn’t spill onto it.
By moving the subject even further away, then introducing an accessory gobo onto the gelled flash, the background colour gets more pronounced and also creates a more interesting pattern depending on which gobo you use. These shots use a gobo from the Lastolite Strobo range, with different coloured gels to really show off the effect.
Once you’ve mastered a single key light in combination with a single gelled background light, it’s relatively easy to move on to an additional flash unit. By adding in another ungelled flash – fitted with a honeycomb grid to avoid light spill – as a rear three-quarter light, this brings in some additional detail onto a subject’s hair and allows you to move your key light further to the side for a more dramatic lighting effect.
If you’re a more experienced studio worker, using ungelled lights on your subject to keep the colours accurate, then using a gelled light on the background, can really alter the look of the shot. You can flood the background with light for a single-colour background effect. Or by using a gel and a honeycomb together illuminating a predominantly dark backdrop, you can create a pool of deep colour that’s hard to create any other way. That’s the technique used to capture this shot of our model who looks like she’s radiating an unhealthy green glow!
This goes to show that not all colours work in all circumstances, and it’s best to carefully match the colours to the clothing and styling to get the feel you want out of the shot.
Take our image of the same model, this time styled differently with a different colour palette.
It’s a four-light beauty set up of a main light and reflector, two rear three-quarter rim/ hair lights and a gelled, gridded background light that can be particularly effective, especially when gel is selected with the final image in mind.
This technique of using multiple flashes on the subject and a gelled, gridded light on the background also works well for product shots, such as in this image of a motorbike boot.
In fact, gels have widespread use in many product shots and it’s a real technical art.
So far our studio shots have used a single gelled light, but it can be fun to use more lights with gels, especially if the gels are not the same colour but especially chosen for effect. Some photographers carefully study the styling and colour of the subject and background then rely on a colour wheel to carefully select a combination of colours that can contrast with or compliment the subject or each other. But it doesn’t have to be too complicated, and for most image-makers, trial and error is not only more fun but can bring combinations that a more scientific approach would be unlikely to have discovered.
One blue gel and one purple gel may not be diametrically opposed on a colour wheel for maximum contrast, but at the end of the day it’s whether the photographer likes his or her image that matters. In the case of this shot of our model, the key light was an ungelled softbox and the light on the background was also ungelled. So using a flash white balance, it means the light on the subject is natural in colour. Then two rear three-quarter hair lights fitted with honeycomb grids were used, one with a blue and one with purple gel. These were aimed to illuminate not only the model’s hair but also her shoulders and torso. You can clearly see the effect of the colours being different on her front compared to her back.
Blue and purple are right next door to each other on the colour wheel, and give a more harmonious effect than two colours that are virtually 180-degrees apart, such as red/orange and turquoise/green. By switching to this exact combination and getting our model to angle herself slightly more towards the camera, this shot
has a totally different look and feel to the blue/purple version. Some may prefer one, others may vouch for the alternative – that’s the joy of photography being an art rather than a science. Either way, changing the look was as simple and cheap as swopping two bits of gel for two others.
And if the look is just too obvious for your taste, then by reducing the power of the gelled lights relative to the main light, and increasing the power of the background light, then the whole look and feel of the shot can be totally changed!
It’s the same technique with the same gelled hair lights, only far more subtle.
We end with two shots that are the opposite of subtle in terms of brightly-coloured lighting. The first shot
uses an ungelled, gridded softbox high above our male subject as a key light. And two more flashes, one fitted with a magenta gel and one with a cyan. The cyan-gelled flash is aimed from behind the subject to put a rim light along the edge of his face, and you can clearly see it on his neck and lips.
The magenta light is aimed towards the background from outside the left of the frame, using a flag to ensure none of this light reaches the model himself.
On the left edge of the frame, it’s clear to see the cyan colour illuminating the background. But as you scan across the frame to the right, this cyan turns towards a more purple colour. This is where the cyan and magenta lighting are actually mixing together to make a different colour. So the shot essentially has three different coloured areas, despite only using two gels.
And for the final shot of our subject with his headphones on, there really is only one main overall colour and that’s a dark blue.
To get this effect, a blue-gelled overhead softbox is used as the main light source. Two rear three-quarter rim lights are used to separate the subject from the background, and these are ungelled. Hence that’s why the rim light might look very white compared to the main light – because it is! It may not be a particularly natural-looking shot, but it does evoke the feeling of a man lost in his own world of music. And creating a mood and feeling can often be a far more powerful photographic tool than a technically perfect and colour-corrected image.
So hopefully you’ve been inspired to borrow or buy some gels and have a go at making some unique images. Using gels can be fun, challenging but ultimately rewarding if it helps you make some great images.