Welcome to part 2 of my White Balance/Colour Temperature tutorial. Last time I covered Light sources and Colour casts, if you wish to read part one here is a link to it —-> White Balance pt 1
Now you are not always going to be shooting using only one lighting source. For example if you are shooting inside and you are right next to a window it’ll either look normal inside and really blue out the window or normal outside and really orange inside.
The camera does not just average out the different lighting sources it chooses one to white balance to. Though sometimes you can get away with it depending on the weather outside.
So what are your options if you can’t get away with it? Well you could frame the window out of your shot and block out the light from it or you could use Lighting gels. Gels are thin sheets or coloured plastic made specially to be used on lights.
In order for the white balance to be proper you need to choose one light source to work with and covert the other ones to the one you chose so that all your light is one colour temperature. Gels are how you convert different lighting sources.
In part one I talked about how the camera white balances by adding certain colour depending on the light source, well in order to understand which gel to use you need to know this.
There are 4 basic colour correcting gels:
- CTB (colour temperature blue)
- CTO (colour temperature orange)
- Plus Green
- Minus green
The CTB is a dark blue gel that converts tungsten to daylight
The CTO is a burnt orange gel that converts daylight to tungsten
The Plus Green is a very light green gel that coverts daylight or tungsten to fluorescent
The Minus Green is a light magenta gel that coverts fluorescent to daylight or tungsten
So in our next to a window example (assuming you are using tungsten lighting inside) You have 2 options with the gels.
- You can use CTB gels and all your lights inside so that all of lighting is daylight
- You can use a CTO gel on the window so all your lighting is tungsten
Option 2 is the easiest to do but sometimes you are in front of a window that is much bigger than any gel you have so you have to use gels on your lights instead.
Just like taking advantage of your camera white balance to and artistry you can also use gels to do the same. All of these four different gels come in 1/2 and 1/4 versions. This is in case you don’t want to convert your lighting fully. So if you want things to look slightly blue you can use 1/2 CTBs on you lights (make sure to white balance before you put the gels on otherwise it’ll negate the effect) or if you want things to look REALLY orange inside you can use a CTO on your lights.
There are gels in hundreds of different colours, the four mentioned above are colour correction gels but there are gels out there just for adding colour.
Gels tend to be around $7.50 a sheet so they are kind of expensive but defiantly worth the investment.
- Geeks_Only