Sunday, 15 May 2011

Working with colour

This section asks us to start taking into consideration the colour of the objects we photograph and the capability of our cameras to accurately capture these. Not thinking about the colour of light at present, but taking this aspect into account the camera should always be set to the correct white balance because the aim of the exercise is to reproduce a scene and its contents accurately. I must admit this was the first exercise that I looked at and groaned ;o) I can see the benefits of completing the tasks but it look so fiddly and time comsuming....sometimes I have to kick myself and remind myself that the mundane and basic experiments often provide the most interesting results and useful information. *KICKS SELF*

The PwDP manual sums it up quite simply (good because some of the scientific sites I looked at went whooshing over my head) reminding us that 'the colour that we see is partly the reflection of the light and partly the properties of the surface itself' and that some objects seem to have 'a different colour under different kinds of light'. This is known as metamerism (suckers for punishment can look here Metamerism if you want to wade through long confusing paragraphs!)

The first stage of checking how to deal with the colour of things is to compare a digital photgraph with the real thing. This is the bit where I laughed and wondered how many people actually unplugged their monitor and all the peripherals to move their pc next to a window? The reason this was suggested is due to the fact that the colour temperature of the window and a monitor should not be far off....luckily my PC isn't too far away from a window......a neutral object was photographed, on a window sill with an Auto white-balance setting. The image was then uploaded to the PC, printed and the colour compared between the real thing, the print and the monitor.

I chose this mug as it has fairly moderate to neutral colouring. The colour match wasn't too bad although the mug itself is a more creamy white than the monitor shows. When the image was printed out it was reasonably close to the monitor hues. I always calibrate my monitor and a few months ago spent quite a while ensuring my colour balance and screen brightness/contrast were as accurate as possible. The image below isn't ideal as I moved the mug from the sill and the print is in front of the monitor but it gives the idea of what the experiment was. The monitor wasn't as blue as this image suggests....

Variations can be caused by the camera, the colour space that the computer and Photoshop are working in and the calibration of the monitor. I make sure I regularly calibrate mine and a few weeks back spent a while making sure the brightness/contrast of my monitor was also set correctly as sometimes my prints were too dark. It is the aim of every photographer (unless into manipulation) that the final printed image is as close to the original scene as possible. However images are most often viewed away from the real object and we have no control over where the photographs will be eventually viewed/displayed. That is another argument altogether so it is a given that common sense should win out in the end otherwise with the alternative lies madness ;o) Seen apart all three are quite acceptable.

In the appendix is an OCA colour chart to study and note the tones, a digital file is also provided but this will differ due to the different range of contrast that paper has compared to a computer screen. You SHOULD be able to see from the two images uploaded here the differences you would expect to see between the monitor images and the printed page.... not sure on my current browser if I can...on my monitor there is a distinct difference....The printed image does not have such pure colours; the colours represent colours likely to be found in real scenes. Intense hues being fairly unusual in nature, these normally are found in advertising etc.

OCA Colour Chart image property of Open College of Arts © 2004 

OCA Colour Chart As Looks image property of Open College of Arts © 2004

The chart Colour Chart mid grey as RGB 128,128,128 zero Hue,zero Saturation and 50% Brightness. Colour charts can be purchased to check the way cameras record colour.

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