Sometimes you can have a fairly complicated lighting setup on your model but stopping all those lights from ruining your gelled background can be a real pain.
In the previous article we spoke about the best ways to perfectly light your background with coloured gels. If you missed it then here's the link 'Creating the Perfect Gelled Background '. In that post I went through the best things to keep in mind if strong and vibrant colours across your backdrop are your objective. It turns out, that gelling your background is actually relatively simple, it's keeping those strong vibrant colours that's actually the tricky part.
What usually happens when we begin a portrait shoot is we setup our key-light to light our subject and once we're happy with that, we then move on to place another flash to light and gel the background. This is your first mistake!
What happens next is we set up the gelled background light, take a picture and see that the background gel colour behind the model looks pretty washed out and insipid. There's no rich colour saturation back there and it's not giving you the colour that is promised on the Jake Hicks Photography Gel Packs at all!
The model looks great though, she's evenly exposed, but the background has no saturation whatsoever. So what do you do? Well it's clearly not the key light, as the model is looking great so we go to the gelled background light and faff about with that by turning the power up and down and start moving it closer and further away….. but to no avail. Obviously the gels must be broken!
Thankfully no, the gels aren't broken and there's a relatively easy solution which simply requires you to turn off your key light that's lighting the model and setup up your gelled background light first. As I described in the previous article, this is the easy bit, getting a great looking gelled background is pretty straight forward, but once you're happy with your gelled background DO NOT TOUCH THIS LIGHT AGAIN.
Yup, getting the gelled background is easy, it's keeping that rich colour that's the real problem. The reason this is strange is because we always set up our lighting with a key-light first and then add and adjust the other lights around it. Key-light, fill-light, then hair-lights and so on, but we need to rethink this process with a background light and treat it like a completely separate setup. Think about it like two different lighting setups in one shot rather than one big one, this way you can clearly separate the two. The background gel shouldn't affect the model and the model lights shouldn't affect the gelled background.
Simple Right?
Ok, so let's assume we've followed all the steps to getting the perfect gelled background. We're in love with the colour we've achieved behind the model, it's looking great with all its saturation and strong colour and we know that once we're happy with it not to touch that light again. What are the things we need to know when setting up our key light on our model to avoid ruining that beautiful coloured background?
5 Reasons your Gelled Backgrounds are Getting Ruined:
Modifiers - Soft light modifiers and hard light modifiers on key lights
Directionality of Key Light - The angle of key light in relation to the model
Distance of Key light to Model - The inverse square law effect
Light Control - Flagging and controlling light spill
Distance of Model to Backdrop - Where in relation to your backdrop to place the model
Don’t panic! I get it, that sounds like a lot of nerd-talk right there, but trust me, if my tiny brain can make this work, anyones can.
The trick to making this easy, is to simply tackle it one piece at a time…
On the left you have the umbrellas and softboxes, these are soft light modifiers and on the right you have grids and snoots, these are hard light modifiers.
1. Modifiers
The modifiers I'm referring to are the modifiers that are attached to your key-light. I'll keep it simple by breaking them into two groups; hard and soft light modifiers. The soft ones are modifiers like softboxes and umbrellas as these spread the light over a far wider area. The hard-light modifiers are the ones that provide a very directional light like the grids and snoots.
If you light your model with a soft light modifier, you need to be aware that your light will quickly and easily spill onto your gelled backdrop unless you take great care to control it properly. Using hard light modifiers is a lot easier to control, but will obviously give you a very different look to the key-light and how it affects your models appearance.
Choosing your key light modifier shouldn't be dictated by whether or not you're using a gelled background, but you should be aware of what effect each one has so you can plan your setup accordingly. If you're using a hard-light then you can afford to be a little more relaxed with its placement, whereas if you want to use soft-lights like softboxes, you need to pay careful attention to the other factors I'll be going over to ensure your background doesn't get washed out.
Take a look at the diagram below to see how different a gelled background looks when using a soft-light on the model compared to when using a hard-light.
On the left is how your gelled background looks before you introduce another light to the set. In the middle we have a softbox as our key light and on the right we have a gridded dish as our key light. It's very clear to see that the key light modifier plays a big role in how our gelled background is affected.
2. Directionality of Key Light
Even though my model is only a few feet from my gelled background, none of the saturation has been lost because I've placed the models key light to one side of her.
The directionality of your key-light refers to which angle you place it in relation to your gelled background. A lot of us like to use varying lighting styles on our subjects like narrow lighting, butterfly lighting, broad lighting, split etc, etc. Some of these lighting styles will lend themselves to gelled backgrounds more than others though.
For example, butterfly lighting is a beautifying lighting technique that requires the light to be directly in front of the model, thereby accentuating symmetry within the look. Conversely, narrow lighting highlights shape and form by placing the light to the side and uses directionality of light to cast shadows on the model in relation to the camera.
Butterfly lighting usually requires you to point the light straight at the model which unfortunately means you often wash out the gelled lighting behind her. Narrow lighting on the other hand requires you to place your light to one side in relation to the camera and model. This usually means that it isn't pointing towards the background. As a result, it doesn't wash out the coloured gel nearly as much.
I appreciate all that came with the expectation you had intimate knowledge about the lighting styles I was referencing, so take a look at the following diagrams to see exactly what I mean.
Never let the gelled background dictate your models key-light. Just because shooting with direct light on the model will make it a little trickier, it doesn't mean you can't shoot popular styles like butterfly lighting, it just means you may have to employ other techniques and workarounds to achieve the desired look.
Butterfly lighting requires our models key-light to be directly in front of her. If we have a gelled light behind her lighting the background, it can mean the background gels are washed out.
Narrow lighting means our key-light is placed to the side of our model and creates more shape and form by casting shadows across our model. The benefit of this lighting is that our key-light isn't pointed towards the background and thereby isn't affecting our gelled light.
In the image above, we've placed our key-light straight on to the model to get the butterfly lighting effect. Unfortunately, as a result we've lost all the saturation on our gel behind her.
In this setup we've opted for a more directional light on our model and we've placed our key-light to the side and not pointed it straight towards the background. As a result, all of the light is on the model and none is on the background.
3. Distance of Key Light to Model
Utilising this technique of bringing your key light quite close the model is often easiest to achieve on beauty shots. The beauty dish key light I'm using here is probably no more than 3 feet from the model and she in turn is no more than 5 feet from the gelled background. Use this technique correctly and you can shoot with gels in very small spaces.
Utilise this technique properly and it may well be the most powerful tool in your lighting arsenal.
The distance of your key-light to your model is crucial to getting uncontaminated gelled backgrounds and it's a common problem that is often overlooked. This is tricky to explain with mere words, but essentially the closer the key light to the model, the less light that actually falls onto the background. The principles of this are based around the inverse square law theory which is a whole other article, but essentially; as you bring your key light closer to the model, the more you have to turn your key light down to compensate for the increase in brightness.
The Inverse Square Law in relation to light states that when you double the distance of the light to the subject, you quarter the amount of light that falls upon them.
For example, if your key light was 2 metres away from your model and you took a correctly exposed picture at f8 (we're assuming a constant shutter speed of 1/160th and an ISO 100 for a normal studio setup) and we moved our key-light closer so that it was now 1 metre away from our model (half the distance) and took a shot it would now be 2 stops overexposed (one stop equals double the light). We don't want to change the settings on the camera because remember our gelled background light is set to those settings, so we turn the power of our key-light strobe down 2 stops (quarter the light to match half the distance moved). If we take a picture now, the model is correctly exposed again.
Like I said this is a real pain to explain coherently with text alone, so let's take look at a diagram below to elaborate on what I mean. Pay close attention to the brightness of the background her. See how different it looks when the light is a lot further away compared to when it’s close?
In this setup our key light is relatively close to our subject but she's evenly exposed.
In this setup we have our key light a lot further away so we have to turn the power of the light up to compensate.
So we can see that by moving the light away and upping the power of that one light, we can still correctly expose the model without having to change any settings on our camera. The same applies if we want to move the light closer, we just have to turn the power of the light down to compensate. We don't have to adjust the camera.
Now lets see what happens when we introduce our gelled background light that we already had perfectly set up before. How does this technique affect the colours of that gel we so painstakingly got right previously.
In this shot our key-light is close to the model and closer to the background, but the gelled background colour has maintained its tone because we've turned down the power of the key light.
In this setup we've moved our key-light a lot further away from the background, but also a lot further away from our model. To compensate for that extra distance we've had to increase the power of the light but in doing so our background gel now looks completely washed out.
As I mentioned a moment ago, if you get your head around this concept, your mastery of lighting will go through the roof and it’s an incredibly powerful tool if you can utilise it to your advantage. I know it's tricky and a little counterintuitive though. When I was teaching this to new photographers in the studio where I worked, this was always the hardest part for them to get their heads around. I think the reason for this is because when you move your light further away from the background you're actually adding more light to the background, whereas normally you'd think that by moving it further away you'd get less light back there. Granted you've added more power the to the light, but it still seems odd when you're starting out that this happens.
There are of course downsides to this technique and that is that by moving your key-light closer to the model you change the effect the light has on the model as well. This is something that you'll have to play with, but if you're happy with how your modifier looks when it's quite close to the model then this may be the technique you need.
4. Light Control
The term light control has many connotations, but in this context I'm referring to controlling the light after it has left the modifier. If you have complete control of your light after it has left the light source, then that means no light is spilling onto your gelled backdrop. This is a little easier said than done, but there are a few little studio tricks that you can employ to ensure your light is only going where you want it to and this technique is often referred to as ‘flagging’ the light. Still-life photographers are absolute masters of this as they’re often working with very small objects like food and bottles, but their light sources are still the same size as ours when we light larger objects like people. As a result, they need to be extra careful of where their light is going and spend a long time before shooting begins ensuring no unwanted light spills anywhere where it shouldn't.
I've used Cinefoil here to mould onto my barn door to create an extra large flag to control the spill of light.
One tool we can use to control the light is Cinefoil or Black Wrap. This is essentially matte black, heat resistant and extra thick tinfoil that we mould onto our lights to control any spill.
It's relatively inexpensive and although more popular in the film and movie industry it's invaluable to have a few sheets in your bag incase you need it. Simply mould it into any shape you want and when you're done, flatten it back back out and return it to your bag for next time. I'm sure the benefits of this speak for themselves but if you're using a hard light source like a snoot or grid a few well placed sheets of this you can make sure that no light from your key light spills onto your gelled background, even if your quite close to it.
I use black velvet sheets as flags instead of the large poly boards when I'm on location. They are portable and cheap, but just make sure you get the cotton based version as the synthetic one acts more like a reflector than a flag.
There are going to be occasions of course when you want to use larger lighting modifiers like softboxes. Flagging unwanted light from a softbox would require either a huge amount of Cinefoil or a larger and easier to manage alternative. One option is black poly-boards, these are present in most studios and they are usually about 6ft high by 4ft wide and painted matte black on at least one side. Simply maneuverer these into place next to your lights and then angle them so they funnel the light away from the background, but still onto your model. I've used these a lot, but I also use a cheap and portable alternative when I'm on location too and that’s simply a couple of large sheets of black velvet. I hang them from spare light stands and they give me complete control of the light after it has left the modifier. It might seem silly at first, but black velvet is great at soaking up unwanted light thanks to its deep texture. Be sure to get the cotton based version though as the synthetic one is shiny and renders it useless as a light flag.
5. Distance of Model to Backdrop
You're nearly there and I'm sure you'll be pleased to know that I've saved the easiest till last. This last solution refers to how far away your model is to the background. Now I know this seems obvious, but you'd be surprised as to how many people place their model right next to their gelled backdrop even though they have the whole studio to play with. Essentially this technique is your 'do whatever you want' card to play. Set up your background gel, then place your model far away from it and you can set up whatever lighting you want with her.
In fact, you can even use the practically forbidden softbox with butterfly lighting from 2 metres away technique if you really want!
The trick to this is to treat this as two completely different lighting setups, each of them being so far apart that they have no influence whatsoever on one another regardless of what you do in them. Obviously there are limitations and you still need to tie the model and background together in one frame with a slightly longer lens, but it's certainly possible in most studios. Up until now I've been dealing with issues that most of us have encountered, but we've only really encountered them because we're dealing with a smaller space like a home studio. Eliminate that space issue and you're free to do as you please.
Even seemingly heretical gelled lighting setups like softbox-lit butterfly lighting from 2 metres away are possible if you separate your model and background. Treat your background and model like two completely different setups and you'll never have to worry about washing out your beautifully lit gelled backgrounds ever again…..as long as you have the space for it that is.
All joking aside, the same principle applies even in smaller spaces too. I even tried this in my front room to see if I could force the effect in a small space as well. The result is that yes, even in small spaces by simply moving your model as little as 3 feet further away from the background like I did in this test, can have a dramatic effect on how washed out your background gels look.
When you're shooting in small spaces you need to be aware of how close your key-light is to the background. Even when I'm using a gridded beauty dish really close to the model, I'm still getting a lot of spill onto my gelled backdrop which is washing out the colour.
By simply moving the model as little as two or three feet further away from the background can have a dramatic difference. Now that you're a little bit further away, your gelled background retains its saturation.
To Conclude…
Well done, you made it to the end and my apologies for the long article on this but I do honestly believe that all the points I've raised here are valid in the pursuit of maintaining clean and saturated gelled backgrounds.
Points to remember;
1. Set up your background light first, before you set up your model lights.
2. Once you've set up that gelled background light correctly DO NOT TOUCH IT AGAIN.
3. Soft light modifiers on your key-light are harder to control and more likely to ruin your gelled background versus hard-light modifiers .
4. Certain lighting techniques like butterfly lighting are harder to implement in small spaces when using a gelled background. Instead, opt for more of a side-lit look like narrow lighting to make it easier to control the spill of light.
5. By bringing your models key-light closer to her and turning the power down, you can actually eliminate any spill of light onto the background.
6. Use Cinefoil, black velvet sheets or poly boards to control and flag the light. Use these tools to ensure no unwanted light falls onto your gelled backdrop.
7. If you have the space for it, don't be afraid to move your model and key-light well away from the gelled background.
So did I miss anything? Is there a crucial element that I've overlooked? Feel free to sound off in the comments below and as always please feel free to ask any questions and I will certainly do my best to answer them all :)
Further reading on gels:
How to perfectly light your gelled backgrounds 'Creating the Perfect Gelled Background'
How many colours can you get from just one gel? 'Colour Gels Exposed'
Some post-pro tips on getting the most out of your coloured gel shots 'Maximising the Colour in your Coloured Gel Shots'
:WARNING: Flagrant Self Promotion Ahead
Want to learn more? Believe it or not the above article just scratches the surface of what there is to know about gelled lighting. If you'd like to know more on how to create gorgeous gelled lighting shots then why not check out one of my Gelled Lighting Workshops where we cover everything from coloured flare in portraits to triadic colour washes in fashion. Click the link to find out more. See you there :)
Need some coloured gels? Why not check out my hand picked gel packs of curated colours that offer you the best saturation and consistent edge to edge tone. I've worked with LEE Filters gels for many years and their quality product offers some of the thickest and longest lasting gels I've used. Follow the link to see what we've put together Jake Hicks Photography - Gel Packs
