Friday, 5 August 2011

Colour Space

Loads of debate and discussion goes on about the use of colour space and is it worth using something which uses a wider gamut that your monitor displays. I read an article a long time ago by Andrew Rodney who gave some insights about what the colour spaces are and problems that can be encountered by using them. It was published in the Professional Photographer magazine October 2005 edition, the review can still be found online. RGB working space debate, Part II, by Andrew Rodney (2005, October)

I took on board his points with regards to using a wide gamut allowing a photographer to archive all the colours that a scanner or sensor can capture that an output device may not and that some printers can print more tones that can be seen on a monitor so have been using Prophoto. Some of the issues surrounding using such a large gamut is editing colours that you can't even see, something he mentions in an earlier article published in 2004, and possible banding. Why you need a working space, by Andrew Rodney (2004, March)

Must admit to not having an issue with regards to colours when printing due to colour space (well to my untrained eye :o/) Any real issues have been with images coming out a little too dark, so have adjusted my monitor brightness, and if non Epson paper is used ensure that my printer has the colour profile for it. Even using the alternative pre set options for the papers I have tested the results come out a bit dodgy...great technical term...The Epson R285 does not have profiles for some papers I would like to experiment with, the manufacturers websites don't provide profiles for lower spec printers, therefore I use only Epson paper and Epson inks.

Wanting to know more about the different colour spaces I did an experiment using the Granger Rainbow

The original file was created using LAB colour space and then converted to AdobeRGB 1998, sRGB and Prophoto, not sure how well the results show online but I could definitely see a shift of the colours on my monitor and then when the images were printed out.

The LAB images looks horrible, with the pinks looking a murky grey/lilac pink, the blue tones were definitely less than shown on the monitor.

The sRGB image when printed was a very close representation to that which was on screen.

The AdobeRGB 1998 image looked very similar to the sRGB and also printed a very close representation.

The Prophoto image also had a fairly close representation to the screen.....

Am not sure how helpful this experiment was as it is a manufactured image, a better test would probably be with a photograph where I could reference to the actual scene to gauge true colours and tones. Looking for smooth saturated tones and colours which they all seemed to, although the amount of ceratin tones and colours shifted maybe I should try with the printer test file I used to calibrate my monitor...hmmmmmmmmm.

Not sure what I have learnt from this exercise other than what was on my monitor was reflected in the printing, so happy with the calibration, although the darker tones are printing a little darker than I'd like still, but not by much. This was more apparent on the Prophoto test, as was less obvious smooth transition between the yellow tones, so a good a reason as any to change my workflow as much as it being the advice of Joe and the problems that you can encounter of trying to edit something you can't actually see.

Printed images are in my learning log.

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