White Balance
Before sharing the tip I have learnt recently about white balance and camera settings, I want to give a very simplified and brief version about why white balance is necessary.
So let’s start with an example, I am reading a book by candle light and I see a white page in front of me, and yet when I take a picture of that page it comes out with an orange cast and doesn’t look white at all. What the camera sees and what the human eye sees are actually very different when it comes to light. The strange thing about this is that what the camera is seeing is actually what is true of that lighting situation and what we are seeing is a colour corrected version of that.
This is because different light sources have different colour temperatures and our brains try to compensate for that. Colour temperature refers to the distribution of the colour spectrum in light, which varies from one lighting situation to another. Daylight has an even distribution of colour and contains equal amounts of the various colours in the spectrum, whereas candlelight does not. The light from a candle contains more reds than it does blues and would be described as a warm colour temperature. When we are reading in candlelight we see white as white because our eyes have adjusted their colour sensitivity to suit the situation. Our eyes will pick up that the light source is emitting more reds than any of the other colours in the spectrum, and will compensate for this by decreasing the sensitivity of the colour-receptive cells in our eyes responsible for sensing red light, allowing us to distinguish the colours of the objects in front of us correctly.
This means that if we want our cameras to see what we see, we have to set them correctly to do so. So my image in candlelight would have come out orange because it was not set to the correct white balance. Most cameras have different white balance settings on them that allow you to tell your camera what the lighting situation is and it will make adjustments based in this information. The list of options on my camera is as follows:
Automatic white balance, daylight (Approx 5200K), shade (approx 7000k), cloudy (approx 6000k), tungsten (approx 3200k), white fluorescent light (approx 4000K), flash and manual.
The approximate values next to each setting are the estimated colour temperature readings of each scenario. Colour temperature is measured in degrees Kelvin and despite what one would predict, light with a cool colour temperature (light which has more blues than reds) has a high Kelvin value and light with a warm colour temperature has a low Kelvin value (I know it’s confusing, but just go with it for now and I promise to give you some useful links on the topic at the end for a more in-depth understanding).
So if you are shooting in shade and you have your camera set to tungsten (a warmer light) your image will come out with a blue cast, and if you are shooting in a room lit by a tungsten bulb and your camera is set to shade, your image will come out looking orange.
To give you an idea of the Kelvin measurements of the different light sources you are likely to encounter here is a list I found…
| 1000-2000 K | Candlelight |
| 2500-3500 K | Tungsten Bulb (household variety) |
| 3000-4000 K | Sunrise/Sunset (clear sky) |
| 4000-5000 K | Fluorescent Lamps |
| 5000-5500 K | Electronic Flash |
| 5000-6500 K | Daylight with Clear Sky (sun overhead) |
| 6500-8000 K | Moderately Overcast Sky |
| 9000-10000 K | Shade or Heavily Overcast Sky |
As you can see these are just some of the lighting situations you might find yourself in and there are more here than there are options on my camera. But this doesn’t bother me, because to be honest I am not too worried about white-balance when I am taking pictures.
I have recently learnt two tricks with regards to choosing the right white balance setting on your camera. The first is that you don’t have to, and the second is that you have to shoot in Raw. This is because I am in the camp of evil photographers who think that it’s ok to correct your white balance on computer instead of getting it right on camera, and shooting in Raw allows me to do this.
The preset settings on the camera are not one hundred percent accurate, and often need tweaking due to the fact that it works on an approximate value to begin with, it can’t account for mixed light sources, there are more light sources than settings and the camera tends to get confused when there is a predominance of a warm or cool colour in an image and can read that as a warmer or cooler light source.
If I am looking for a completely 100% accurate reading, the best thing to do would be to use manual white balance, in which case I would get a piece of white/neutral colour card, take a picture of it and tell the camera to adjust its settings so that it reads that card as white. This works well if I have a controlled environment like a studio, or if I have the luxury of time, but in a wedding I have neither. I am constantly moving between different lighting situations and the action doesn’t wait for me.
Leaving my camera on one setting means that all of my images from one lighting situation will need the same colour correction, which allows me to batch edit them. If I were shooting in auto I would have a slightly different white balance for every image and would have to spend hours editing them individually. So I find it much more logical to simply lock my camera on daylight and wait till I am at my screen to correct. This way I save time, get consistency and can still get an image that looked like what I was seeing at the time I took it. As I am not a fashion photographer who needs 100% accuracy this works pretty well for me and using my eye in post is a perfectly acceptable way to get the image looking right. So if you are a fellow evil photographer willing to correct your colour balance in post, then I hope you find this blog entry useful.
I have tried to keep this as simplified as possible but there is a lot to read online about white balance and colour temperature and I had quite allot of fun getting a bit more into the science of it, so if you want to know more, I have some links that I found useful…
Duncan Davidson was able to write two blog posts on these topics that were in-depth and yet understandable with good illustrations and they were : Measuring the Colour of Light http://blog.duncandavidson.com/2008/04/kelvins-and-the-color-of-light.html) and Colour Temperature and white balance (http://blog.duncandavidson.com/2008/04/color-temperature-and-sensors.html).
If you are still with me, thanks for passing up on that warmer colours having a lower colour temp earlier, here are the links as promised(http://www.schorsch.com/kbase/glossary/cct.html, http://www.cambridgeincolour.com/tutorials/white-balance.html ) and a quick blurb on my understanding of this. To get a black body (as described in Duncan Davidson post on measuring the colour of light) to emit blue light means that you have to heat it up much more than you would to get it to emit red light. Typically “warmer” colours like your reds and oranges have longer wavelengths, and tupically “cooler” colours have shorter wavelengths, but it is these shorter wavelengths that actually contain light of a higher energey. If you have ever heard of something burning white hot and understood that it was hotter than red hot, or have ever been told that a blue flame is hotter than a red flame, and you apply that knowledge to this situation, then it all starts to make a bit more sense… (http://van.physics.illinois.edu/qa/listing.php?id=1545) 🙂
Before sharing the tip I have learnt recently about white balance and camera settings, I want to give a very simplified and brief version about why white balance is necessary.
So let’s start with an example, I am reading a book by candle light and I see a white page in front of me, and yet when I take a picture of that page it comes out with an orange cast and doesn’t look white at all. What the camera sees and what the human eye sees are actually very different when it comes to light. The strange thing about this is that what the camera is seeing is actually what is true of that lighting situation and what we are seeing is a colour corrected version of that.
This is because different light sources have different colour temperatures and our brains try to compensate for that. Colour temperature refers to the distribution of the colour spectrum in light, which varies from one lighting situation to another. Daylight has an even distribution of colour and contains equal amounts of the various colours in the spectrum, whereas candlelight does not. The light from a candle contains more reds than it does blues and would be described as a warm colour temperature. When we are reading in candlelight we see white as white because our eyes have adjusted their colour sensitivity to suit the situation. Our eyes will pick up that the light source is emitting more reds than any of the other colours in the spectrum, and will compensate for this by decreasing the sensitivity of the colour-receptive cells in our eyes responsible for sensing red light, allowing us to distinguish the colours of the objects in front of us correctly.
This means that if we want our cameras to see what we see, we have to set them correctly to do so. So my image in candlelight would have come out orange because it was not set to the correct white balance. Most cameras have different white balance settings on them that allow you to tell your camera what the lighting situation is and it will make adjustments based in this information. The list of options on my camera is as follows:
Automatic white balance, daylight (Approx 5200K), shade (approx 7000k), cloudy (approx 6000k), tungsten (approx 3200k), white fluorescent light (approx 4000K), flash and manual.
The approximate values next to each setting are the estimated colour temperature readings of each scenario. Colour temperature is measured in degrees Kelvin and despite what one would predict, light with a cool colour temperature (light which has more blues than reds) has a high Kelvin value and light with a warm colour temperature has a low Kelvin value (I know it’s confusing, but just go with it for now and I promise to give you some useful links on the topic at the end for a more in-depth understanding).
So if you are shooting in shade and you have your camera set to tungsten (a warmer light) your image will come out with a blue cast, and if you are shooting in a room lit by a tungsten bulb and your camera is set to shade, your image will come out looking orange.
To give you an idea of the Kelvin measurements of the different light sources you are likely to encounter here is a list I found…
|
1000-2000 K |
Candlelight |
|
2500-3500 K |
Tungsten Bulb (household variety) |
|
3000-4000 K |
Sunrise/Sunset (clear sky) |
|
4000-5000 K |
Fluorescent Lamps |
|
5000-5500 K |
Electronic Flash |
|
5000-6500 K |
Daylight with Clear Sky (sun overhead) |
|
6500-8000 K |
Moderately Overcast Sky |
|
9000-10000 K |
Shade or Heavily Overcast Sky |
As you can see these are just some of the lighting situations you might find yourself in and there are more here than there are options on my camera. But this doesn’t bother me, because to be honest I am not too worried about white-balance when I am taking pictures.
I have recently learnt two tricks with regards to choosing the right white balance setting on your camera. The first is that you don’t have to, and the second is that you have to shoot in Raw. This is because I am in the camp of evil photographers who think that it’s ok to correct your white balance on computer instead of getting it right on camera, and shooting in Raw allows me to do this.
The preset settings on the camera are not one hundred percent accurate, and often need tweaking due to the fact that it works on an approximate value to begin with, it can’t account for mixed light sources, there are more light sources than settings and the camera tends to get confused when there is a predominance of a warm or cool colour in an image and can read that as a warmer or cooler light source.
If I am looking for a completely 100% accurate reading, the best thing to do would be to use manual white balance, in which case I would get a piece of white/neutral colour card, take a picture of it and tell the camera to adjust its settings so that it reads that card as white. This works well if I have a controlled environment like a studio, or if I have the luxury of time, but in a wedding I have neither. I am constantly moving between different lighting situations and the action doesn’t wait for me.
Leaving my camera on one setting means that all of my images from one lighting situation will need the same colour correction, which allows me to batch edit them. If I were shooting in auto I would have a slightly different white balance for every image and would have to spend hours editing them individually. So I find it much more logical to simply lock my camera on daylight and wait till I am at my screen to correct. This way I save time, get consistency and can still get an image that looked like what I was seeing at the time I took it. As I am not a fashion photographer who needs 100% accuracy this works pretty well for me and using my eye in post is a perfectly acceptable way to get the image looking right. So if you are a fellow evil photographer willing to correct your colour balance in post, then I hope you find this blog entry useful.
I have tried to keep this as simplified as possible but there is a lot to read online about white balance and colour temperature and I had quite allot of fun getting a bit more into the science of it, so if you want to know more, I have some links that I found useful…
Duncan Davidson was able to write two blog posts on these topics that were in-depth and yet understandable with good illustrations and they were : Measuring the Colour of Light http://blog.duncandavidson.com/2008/04/kelvins-and-the-color-of-light.html) and Colour Temperature and white balance (http://blog.duncandavidson.com/2008/04/color-temperature-and-sensors.html).
If you are still with me, thanks for passing up on that warmer colours having a lower colour temp , here are the links as promised(http://www.schorsch.com/kbase/glossary/cct.html, http://www.cambridgeincolour.com/tutorials/white-balance.html ) and a quick blurb on my understanding of this. To get a black body (as described in Duncan Davidson post on measuring the colour of light) to emit blue light means that you have to heat it up much more than you would to get it to emit red light. If you have ever heard of something burning white hot and understood that it was hotter than red hot, or have ever been told that a blue flame is hotter than a red flame, and you apply that knowledge to this situation, then it all starts to make a bit more sense… (http://van.physics.illinois.edu/qa/listing.php?id=1545) J
The World in Thirds 