We've all done it, grabbed a fresh pack of gels and opened them up to see those vibrant and saturated colours that match the brightly coloured swatches on the back of the packet. We throw them on our lights and take some shots only to find that the actual colours appear nothing like we first thought. But why?
In this article I will take a look at a couple of reasons as to why our first attempts into gelled lighting can be a little frustrating and disappointing. Hopefully with some of the tips I point out here, you'll be well on your way to richly saturated coloured gel shots in no time.
First and foremost the biggest reason for rubbish looking colours when using gels is exposure. I am of course referring to how bright or dark you have your gelled light in relation to the camera.
Correctly exposing coloured gels is arbitrary at best and the sooner you come to terms with the fact that there is no right way to correctly expose them, the happier you'll be with the results.
The diagram above illustrates this point by showing you that the colour and tone of the gels changes drastically with exposure and although this might seem obvious enough it's easy to fall into the trap of trying to 'correctly' expose something. All 13 of the gels used here were all shot with the gel relatively close to the wall as I wanted to include the hotspot and its falloff of light within the image. As a result you will probably witness many stops of exposure difference within any single frame but it helps to illustrate just how many different tones can be achieved with gel exposure alone. If you would like to even out the colour and maintain a more uniform tone throughout the frame (no hot-spot or vignetting) then you will either need to move your gelled light further away from the wall or make the gelled light source larger. More information can be seen on this in this article Creating the Perfect Gelled Background
As I mentioned earlier I tend to always under-expose my gels and as you can see from the gel diagram above the colours of the gels exposed at f11 or f16 are a lot more saturated and deeper in colour.
Remember these stops are just numbers, try to think it as two or three stops darker than your models key light or camera setting.
With the gels appearing darker like this you tend to have a more consistent colour throughout your frame as well and they appear to have a more even exposure too.
Another major factor to bear in mind is how other lights in the shot will affect the exposure and the colour of your gels.
Trying to minimise the spill of light from other light sources onto your gelled colours will certainly help to maintain and hold their saturation. If for example your models key light is spilling onto your gelled background no matter how much you under-expose your gels to maximise saturation they will always look washed out. There are a few ways to combat this, you could flag all the lights that might be spilling onto your background or increase the inverse square law theory (essentially move your key light closer to the model thereby increasing the falloff rate of light to the background) this is a last resort as this will of course change the properties of light i.e hardness of light falling onto the model. Alternatively the easiest and usually the most overlooked solution is to move your model and all other lighting away from the gelled background. Try to treat it like you are lighting two completely separate sets, your model and your background, no light from either set should affect one another. When your background was a white wall it obviously matters very little if your models key light is spilling onto the background, with gels however this additional light falling onto the colour will 'contaminate' it and drastically change its appearance. Colour contamination is literally a whole other article in its own right so if you'd like to learn more on the finer details of avoiding it you can see everything explained further here KEEPING Perfectly Lit Gelled Backgrounds
One other key point when exposing for gels is to remember that not all gels were created equal. As you can see from the gel exposure diagram at the top of this article, even though they were all shot at the same time with the same settings, some gels are blown out completely and some are very dark at the same exposure. This is because some highly saturated gels like reds and blues need to be physically quite dense or thick, this in turn reduces the amount of light that passes through them which gives them the impression of being darker and more saturated. Conversely some gels like the yellows are very thin and let a lot of light through them. This may seem obvious but the point I'm trying to make is that there isn't a strict rule of every time you use a gel you need to underexposure it by 2 stops. Some gels will need a lot more or less power than others and over time you'll get used to which ones require more light. It may even be a good idea to do a similar test to the one I did yourself with your own gels and see what colours can be obtained with your specific gels and get a feel for what they look like over and under exposed (lighter and darker relative to the cameras exposure).
Key points to take away:
- There is no correct exposure for your gels, only lighter resulting colours and darker resulting colours relative to your cameras exposure setting.
- Your gels will appear more saturated the darker they are in the image.
- Darker gels appear to give a more even tone throughout the frame.
- Moving your gelled light further away from your background will give you a more even exposure from edge to edge and a more even colour throughout.
- Minimise the contamination (light spill) of other light sources on the set, this is especially noticeable on some of the thinner gels (i.e. yellow).
- Not all gels were created equal, some of them are very thick and will need a lot more light to create certain effects. These are usually the very saturated colours like the reds and blues.
Of course if you don't already own some gels and you're looking to get some, please feel free to take a look a the collections of gels I've put together too. These collections of gels are what I use day to day to create some of the most highly saturated colours around. If you're looking at getting into gelled lighting or need to get stronger and richer colours in your coloured gel work why not check out my Jake Hicks Photography Gel Packs
If you guys have any questions about any of the topics I've mentioned or if you have anything to add, please do so in the comments below as I'd love to here your thoughts too :)
Thanks for reading :)
:WARNING: Yet more opportunities to spend money on cool stuff below :D
If you're interested in any of my work and would like to know more about how I created some of my shots then why not check out my workshops. Here you can find out everything there is to know about Gelled Lighting, Long Exposure Flash Photography and my entire Post-Pro Workflow. Jake Hicks Photography - Workshops
I have also just released a brand new 22 hour complete Gelled Lighting Tutorial video. I go over everything from studio lighting setups with gels to being on location with gels plus I also go through my complete retouching and post pro workflow. For more details and complete breakdown of everything that's include check out my Coloured Gel Portraits Tutorial
I also offer comprehensive coloured gel packs. These collections of gels are what I use day to day to create some of the most highly saturated colours around. If you're looking at getting into gelled lighting or need to get stronger and richer colours in your coloured gel work why not check out my Jake Hicks Photography Gel Packs