torsdag 25 juni 2015

Photo tips: White balance (WB)

Hi there! This is the first post in a series of photo tips. I hope you will enjoy it and find it helpful. To write this post I spent quite some time putting together the right content and testing out with different photos. I would really appreciate feedback on this so I know if it was worth the effort or not so please email, comment or like to let me know if I should continue! :)

What is WB?

WB decides how the colours of your photo is going to look. With different WB's the colours change a little, this is to make the colours of the photo to remain natural. WB need to change the photos colour because different lighting have a slightly different colour. When the lighting changes colour the reflection of objects change which gives the photo a colour change if you don't have the right WB. The colours are controlled by the warmth of the light source and that is measured in Kelvin.

How to change WB

If you would like to manually change your WB it can be done with almost every SLR and the setting is found in the menu. To be able to change the WB your camera might need to be set at a manual setting.

When you change WB you will most often be able to choose it by names like "cloudy", "daylight", etc. But you can also chose WB by the kelvin temperature you put in yourself at "custom WB setting". If you can't change your WB it's most likely put on a automatic mode where the WB is changed by the camera itself.

To have your WB at a auto mode can be good because it's easy to just take some quick photos. It works good most of the time but if you move around your motive you can end up getting photos that vary in colour because your camera might have used different (and maybe not always the right) WB. This also tend to not work very well indoors when the lighting is more yellow.

What WB is right when?

Sometimes it can be hard to get the right WB. If you are unsure if you are using the right WB try and focus on something in the photo that you know should be white or grey. If the colour you see in the photo isn't white/grey chances are that you are using the wrong WB. Try and use the setting with the right name for the situation as you see in the picture above. Or you could just use the picture to the right and experiment by yourself.

It's also good to remember that you should try and put your WB after where your motive are and not where you are. To give an example: You are outside and it's full sunlight where you stand so you put your WB on daylight. The motive you are taking photos of is standing in the shadow of a tree. Your photos get colour cast because you didn't put the right WB according to the motive. Maybe try "shade/cloudy" instead? If it's still not working you can try and use "custom WB setting" until you get a good result. Remember that it's hardest to avoid colour cast when you are in the yellow/red zone on the photo to the right.

Colour cast

When you use the wrong WB you will get a colour cast. You can see it by looking at parts of the photo that should be white/grey as I told you about above. A colour cast causes the photo's colour to change tone. Sometimes to a yellow tone, sometimes to a blue tone, etc. But a colour cast doesn't always have to be bad. If you change your WB carefully you can, to give an example, change a photo with a cold tone to a more inviting warm tone. If it's done right, a colour cast have the ability to improve a photo so try and take many photos with different WB (if you don't want to edit it afterwards), maybe you will like the result with a little bit of colour cast better?

The original photo - a bit too cold in my opinion.
The edited photo, a bit warmer with a filter of red.

Undo colour cast

To get an unwanted colour cast undone isn't that hard. Most of the time it's quite simple, all you need is to know a little about the colour wheel. What you need to do in order to undo a colour cast is to naturalise the "wrong" colour by adding a layer of it's complementary colour. As you can see in the photo below the complementary colour is the one on the opposite side in the wheel - blue and orange, red and green, yellow and purple, etc.

Examples with blue

This photo of the flowers tuned out looking a bit blue because I took the photo with a too high WB. The complementary colour to blue is orange in the colour wheel so I put on a yellow filter and the flowers now look white as they should.

















Example with yellow

I took this photo some months ago, it's shoot indoors with very little natural light because it was late in the evening. Using the same method as above I put on a purple filter and things looked better. The filter I used was not very strong so I ended up putting on another filter in order to get rid of the last yellow.











So let's end with a short summary of this post: Cameras use WB to make the colours of the photo look right whether you are out in the sunlight or inside with electrical light. You can (and should) change the WB according to your motives location. This can be done manually but most cameras also have a setting where the camera itself automatically change WB according to what it find right. If you use the wrong WB your photo will get a colour cast, sometimes that's a bad thing and sometimes not. A colour cast is basically when a photo has an offset to any other colour. Old photos can naturally get colour casts as well, especially if they are exposed to much sunlight. You can undo a colour cast by using the complementary colour in the colour wheel.