You're Smarter Than Your Camera - White Balance and Lighting
Good morning and welcome to blog number 13. You must be getting a little more confident with your camera now and I hope you have come to the conclusion that it is a great investment of your time to learn to take control over your camera and switch off those auto-settings. As the technology gets more and more sophisticated, I guess there could be a day where cameras can make better informed decisions that people, but we're not there yet and when and if we do get there.....I think our world will be changing in many ways....anyone see Tomorrowland?
Anyway ....onto the July theme - White balance and lighting. This week we will focus on white balance - what it is and why you need to consider it. As we go through the month, I will introduce other lighting techniques and also how they impact white balance. So here goes...
Enjoy your week and as always...keep snapping :-)
White balance is a setting on your camera that informs the camera about the type of light it is receiving in order to make an image. Eh? Light is light right, its white, unless its not...right? Wrong! What looks like the same white light to us, can be very different to a camera. There are varying degrees of colour temperature of a white light source. Three colours are necessary in order to create white light - red, green and blue.
So let's take a look at the settings on a camera that help us manage these changes in the light we are working with.
Below is an image of the Nikon D7000 showing the settings that you can use to adjust the White balance. I have 9 options to choose from - see the screenshot of the options below.
There is also a preset manual setting which I will go through in the 3rd week of this blog. This is essentially where you can use an image taken by the camera in the light you have available and the camera configures the correct White Balance setting. It is a very accurate method of setting the White balance.
Let's Talk about Colour Temperature a little More...
Normally I would save this sciency stuff until the 3rd week, but I think this helps to understand the concept of colour temperature. The colour temperature of the light is that which is radiated from a blackbody (ok..so I don't want to get into it all that deep) so lets just assume that our blackbody is a horse shoe being made. When the iron is heated, the temperature varies and the horse shoe changes colour - when it is cooler, it contains more red and orange colors and when it gets hotter it changes to blue and white light. This is shown on our graph below. Light which has a cooler temperature contains more red and orange colouring - see the 3000K line against the intensity of each colour.
The colour temperature of light varies from 3000K (Kelvin) to 15,000K. This is a very clear table showing the various colours we work with (www.exposureguide.com).
So Why Do We Care?
Let's take a look at the following images. They display the same image when taken with different lighting. The slightly orange, red glow would be with a tungsten light and the image with the blue cast would be taken under incandescent light. This is the effect you can expect if you don't adjust your white balance before you take your image.
This image has an incandescent (cooler, blue) light color cast
This image has a tungsten (warmer, yellow/orange) light color cast
This image is correctly white balanced - so the color of the subject matches that in real life
Put yourself in a shooting situation where you think the White balance might be difficult to manage, indoors is always a good place to start. Change the white balance setting to daylight and take some images. Then change the white balance setting to the indoor setting and see what effect this has on your images. Hopefully you will be able to see why when you take images inside or using candlelight, you get a very orangy glow to the images unless you have the correct white balance.
I hope there wasn't too many charts and tables in this blog, but I thought it all helped to provide an understanding of the wide variation in actual colour when we think we are working with 'white' light. White balance isn't something we can control just in camera, it is also adjustable in good developing software. And the manual setting for white balance offers you the ability to accurately define the light you are working with, we will cover this over the next couple of weeks too.
Until then, thanks for reading and enjoy your photography :-)
As always, I would love to hear any comments or questions you have.