Wednesday, January 2, 2013

Death Valley Revisited and What are Color Spaces?


At the beginning of December, I had the pleasure of presenting a workshop on Lightroom 4 in conjunction with the Barefoot Contessa Photo Adventures field workshop run by Margo Pinkerton and Arnie Zann, two highly accomplished photographers and wonderful teachers.  This was my second effort for Margo and Arnie, the first occurring in Taos, New Mexico earlier last year.  In 2013, I will be presenting the Lightroom workshop again prior to the Colorado workshop in September, and then I will stay for the field workshop as a Lightroom resource person.  I will also attend the Summertime on the Maine Coast workshop as a Lightroom resource person beginning July 28.  Because of logistics (i.e., a lack of adequate meeting facilities), I won't be able to provide the Lightroom workshop before the Maine field workshop.

If you have never gone on a photography workshop, seriously consider attending a Barefoot Contessa Photo Adventures field workshop.  I attended my first BCPA workshop in 2007 (New England).  Since then, I have attended BCPA workshops in Moab, Utah, Yosemite Valley, California, Belize, and Costa Rica.  In February, my wife, Kathy, and I will attend another BCPA workshop in Cuba.  I have never been disappointed and I have met so many wonderful fellow photographers.  I have also improved my own photography as a result of the interaction with Margo and Arnie.  They always put the attendees ahead of their own photo activities.

The recent trip to Death Valley was my third venture to that strange and beautiful location.  I thought Death Valley was nothing but desolation and lots of sand.  Both of these beliefs are wrong.  There is great diversity and very little sand.  Every time I visit, I return to Zabriskie Point and to Badwater.  They are iconic locations  that provide a great deal of variety depending on the time of day and the season.  Perhaps my favorite part of Death Valley is Titus Canyon.  It is a significant time commitment because of the length of the canyon and the need to travel out of Death Valley to enter the canyon.  Travel is in only one direction, so once you begin you are committed to continue to the end.  It is well worth it.  I wasn't able to do the canyon this time around.  I have never made it to Eureka Dunes or to the racetrack, partly because of the distance from Stovepipe Wells and the poor road conditions.  Maybe next time.

So here is a sampling of my efforts during the five days I travelled around Death Valley with Arnie and Margo.  For me, it was my most successful trip there yet, and not likely to be my last.


For the last three years, I have taught a workshop at the Viewpoint Photographic Art Center in Sacramento, California, entitled "Digital Fine Art Printing" that attempts to demystify the entire digital printing process.  One of the great attractions of creating digital images is the ability to control all aspects of the creative journey, from capture, through post-processing, and finally to the final exhibition print.  It is easy to get bogged down in calibration, rendering intents, color spaces, black point compensation, sharpening for output media, and icc profiles.  I thought I would take this opportunity to help people better understand the importance of color spaces.

For photographers, we are able to concentrate on three absolute color spaces, sRGB, Adobe RGB (1998) and ProPhoto RGB.  First, we need to understand what is meant by a color space, and also the meaning of gamut.  We are used to seeing color as being represented by three numbers, each ranging from 0 to 255, which is 256 values, or 2 to the 8th power (corresponding with 8-bit depth).  Red would have a value of 255, 0, 0.  Green would be 0, 255, 0, and blue would be 0, 0, 255.  This numbering system is known as a color "model".  To be useful in communicating color information among devices, it is necessary to assign the color model to an absolute color space.  Here is a diagram that shows three color spaces: CIE xy, sRGB and Adobe RGB (1998).  The entire set of colors shown is the CIE xy color space, which is the range of colors that the human eye can see.  The two triangles represent sRGB (smaller triangle) and Adobe RGB (larger triangle).  The highest tip of each of the two triangles represents green and would have the values of 0, 255, 0 in both color spaces, but as you can see would have very different appearances of green.  That is why the color space is so important in being able to communicate among devices.

The area encompassed by the triangles is called the "gamut" for that color space.  As you can see, the gamut for sRGB is significantly smaller than Adobe RGB.  Web pages use the sRGB color space whereas printers use either the Adobe RGB or ProPhoto RGB color spaces.  Here is another diagram that shows the ProPhoto RGB color space in relation to the CIE xy color space and the Adobe RGB color space.

As you can see, the ProPhoto RGB color space is significantly larger than the Adobe RGB color space and also includes colors within its gamut that cannot be seen with the human eye.  I don't have time or space to fully discuss the relative pros and cons of Adobe RGB and ProPhoto RGB, so I need to direct you to another site for that discussion.  Uwe Steinmueller posted an essay on the Digital Outback Photo website that explains why the ProPhoto RGB color space is preferable to Adobe RGB.  Be aware that this conclusion is only supported if you use 16 bit images, rather than 8 bit images (like jpegs).  Here is a link to the essay.  The simplest statement that can be made is that your images will have less potential "banding" if the original image colors fall within the gamut of the chosen color space.  If they don't, then rendering intent comes into play, which is an entirely different discussion, perhaps to be covered in my next blog.  As a result, larger color spaces tend to create the fewest issues regarding properly reflecting the original colors of the scene in the final print.

Well, enough for this installment.  Next time, I want to share images I captured over twenty-one visits to the Gladding McBean terra cotta factory, starting in 2006 and ending in 2011 when the working factory was closed to photographers.  I have narrowed the collection down to slightly less than twenty B&W images out of a final cut of approximately ninety images.  It wasn't easy.

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