Ansel Adams: resolution, dynamic range, and gamma

I recently went to see an Ansel Adams exhibit entitled At the Water’s Edge,” at the Peabody Essex museum in Salem, Massachusetts.  I have had several such encounters over the years, and encounters are truly what they are.  Years ago I went to an exhibit at the Palace of Fine Arts in San Francisco, then again in San Francisco about ten years later, and then there was a major retrospective at the Museum of Fine Arts in BostonWhat I find interesting is how my view of photography and these works,  in particular, has evolved.

Early on I was taken by the sharpness of detail, how you can see every blade of grass or every nuance in the bark of a tree.  Sharpness in a picture relates to what we call resolution.  Later, particularly at the MFA exhibit, I was taken, really overwhelmed, by the dynamic range in these pictures.  Dynamic range, as already suggested, is the number of shades of grey between black and white in your picture.  The power of Adams; pictures, their inherent luminescence, owes widely to careful placement of the dynamic range.   This is the zone system that Adams’ created.  He would painstakingly measure the brightest and dimmest elements in his picture and then develop, first the negative, and then the print so as to just place these levels within the gamut of grey levels that the photograph allows.  Ultimately, the choice of film developer, paper developer, exposure times, and development times – not to mention some very well chosen dodging and burning in, modified the linearity of response in the final print, the so called gamma.  Linearity means, plain and simple, if I double exposure does recorded density also double.  If it isn’t then gamma isn’t one.

In the next few weeks, I’d like to explore all of these photographic elements in detail.  The point, for now, is that achieving a “technically good” image requires matching.  You’ve got to match the resolution of your lens  to that of your detector, be it digital or film, and then to the resolution of your print, be it a computer screen or printer,  And then the printer resolution needs to be matched to the resolution of the paper as the eye sees it.  Similarly you’ve got to match the dynamic range in the scene to that of the detector and then again to computer screen, printer, and paper. Again, as always, the eye is the ultimate arbiter and task master.

In the world of analogue photography Adams’ zone system was very hard to implement and exploit for 35 mm roll film cameras. Simply because it was hard to keep every picture in the roll within the same set of exposure and development conditions, there was a lot of compromising to be done.  However, just as Eastman’s invention of roll film made it so easy to take pictures, that they for the most part became bland and mediocre, digital photography, particularly if you shoot in raw format, has brought technical proficiency easily within everyone’s reach.  You are left to concentrate on artistic vision.  And as I walked through At the Water’s Edge, I came to realize that when all was said and done, Ansel Adam’s greatness lay in his vision.

This entry was posted in Technical Aspects of Photography.

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  1. By Majestic elms | Hati and Skoll Gallery on February 25, 2014 at 6:30 am

    […] appeal to a mythic chord within us, and of some of the great photographers, like Beth Moon and Ansel Adams, who have excelled in capturing this special subject.  So not surprisingly I was taken this past […]