Project 4: Your Camera's Colour Performance.

This project continues the theme of understanding the limits of your equipment so as to gain the best results possible. Having found the Dynamic range of the camera we now move onto how it captures colour and how this can be processed further using basic tools in Photoshop.

Before we get to actually understanding what the camera is capable of capture we are told about certain limiting factors that will effect how the colours may appear in digital images, these being:-

1. The way the computer monitor is set up because if it isn't set correctly it can produce false colour cast that means you'll over process the image and end up with a final shot that does mirror what you originally saw.
2. Photoshop software can also produce a similar problem if it doesn't recognise how your camera has dealt with capturing the colour
3. Finally if you print your image you may find it doesn't match the original, this can be down to a couple of factors either dew to the inks that you are using or the kind of paper that the image is printed on.

Luckily for me I'd previously resolved these problems by already checking that my computer and software were set up correctly and that when it comes to printing my work i tend to use a site like Photobox or Kodak that do the printing process for you thus making sure i end up with good quality prints.

To understand how the camera I'm using captures colours what you're asked to look at is a Colour Chart supplied within the course material, what this is is a grid of naturally occurring colours that can help us to see how the camera is set up. First your asked to take a print out of the colour chart and and place it in the daylight somewhere there are no shadows present, then setting your camera to the appropriate white balance (clear daylight setting) fill the frame with the chart and take the picture. Below you'll see the results.

My Colour Chart.

Colour chart Aslooks.

Next you ask to open a file called aslooks and to compare it with the shot you've taken, the aslooks file begin a representation of the colours as produced in photoshop. The obvious thing straight of is that the aslooks colours are far stronger and much brighter then in my own colour chart for example if you look at the white square on the top row in the right hand corner in my shot it looks a little lighter than the grey square next to it and the yellow square in the third row is nearly orange in colour, the question is why. The simple answer is its down to the natural light which has a slightly blue cast to it that isn't visible to the naked eye as our brain and eyes interpret the light differently while the camera capture the light and colour produced more naturally. The effect this blue colour cast has can be seen when i take the RGB readings for each chart, in my chart the readings in the top row are as follows from left to right-

• R-38, G-38 B-48
• R-58, G-64, B-76
• R-95, G-104, B-119
• R-137, G-142, B-162
• R-150, G-155, B-175

Compare this to the Aslooks chart-

• R-17, G-17, B-17
• R-52, G-52, B-52
• R-97, G-97, B-97
• R-161, G-161, B-161
• R-243, G-243, B-243

What it shows is that in the darker colours it doesn't have a lot of effect but as the colours grow lighter the added blue makes them appear darker then they actually are.

To fix this i can use the Auto Colour Correction tool in photoshop which will remove the colour cast and put the colours back to there more normal tone, below you can see the result of using this process on my own colour chart. Straight away you can see that the colours appear much brighter and closer to the aslooks chart but i still don't think its spot on.

My Colour Chart- Colour Cast Removed.

In the course material it explains that these still visible differences are down to the way different makes of digital camera sensors capture the light. In my case my Canon EOS 400D seems to capture the colours slightly lighter then they actually are. The is obvious a good thing to know because it means that i can adjust the camera appropriately in conditions where i feel the colours need to be a little less bright knowing that the camera is over doing them a little. This conclusion is back up when you compare the RGB readings for the other three rows in the two charts.

My Colour Chart

Second Row (left to right)

• R-104, G-77, B-70
• R-231, G-175, B-178
• R-214, G-139, B-83
• R-198, G-159, B-138
• R-233, G-205, B-193

Aslooks Chart

Second Row

• R-77, G-49, B-45
• R-204, G-103, B-109
• R-211, G-117, B-56
• R-173, G-117, B-92
• R-223, G-173, B-150

There's no point including the rest of the result as they continue in the same trend showing that my chart is constantly brighter than the aslooks chart.

This project has open my eyes to a fact i wasn't really aware of although i have always used the photoshop software to make small alterations to my work i never considered why i was having to do this so often but now i see that i have to consider that the camera sensor can't always be trusted a 100% to capture colours as truly as i like.