What is “Acceptable Sharpness”?Posted by drfl on December 23rd, 2009
A few weeks ago I wrote an article entitled “How to get Sharp Enlargements: Breaking the Megapixel Myth”that gave some tips on creating images that could be greatly enlarged. Now, I am going to address the issue of “Acceptable Sharpness”. In a perfect world of capturing sharp photographs we would all have a remote similar to the movie “Click” in which we could simply hit the “pause” button and everything would simply stop. At that point we could setup our gear, put our tripod in place, connect our cable release, set the mirror lockup, choose the sharpest aperture, put on the best lens, fix the lowest ISO, and then finally capture the image. Unfortunately, no such device exists and so we are left to deal with breezes that blow, animals that run, and hands that shake and As a result, not all nature images are studio perfect. When zoomed in and analyzed imperfections may be noted, perhaps a little motion blur, perhaps a bit of depth of field issues and of course, hand held photographs will almost always be less sharp than an image from a tripod mounted camera. Does this mean that these images should be tossed out due to technical imperfections? At what enlargement point would these images degrade? These are the questions that led me on my path to finding my “Acceptable Sharpness”.
“Acceptable Sharpness” is different for every photographer and every use. Some photographers require high levels of sharpness regardless. Generally, as a photographer improves the level of “Acceptable Sharpness” also increases. I personally feel that I require a high level of sharpness for my photographs as many are enlarged quite a bit. At the same time, I realize that some uses may allow a lower level of sharpness. For instance, while capturing the image below, there was a steady breeze flowing through the forest. The breeze was not great enough to blur all the flowers for a surreal image and it never stopped enough for me to get an image for all the flowers to be perfectly still. Even after bumping up the ISO, there still wasn’t enough light to get a shutter speed capable of freeze all the motion. For me, the “Acceptable Sharpness” of the original image is too low for an enlargement beyond about 11×14. To address this issue, I have created two versions of this image, the original version that would be perfect for uses such as wall calendars, planners, and the link and another version with a creative “Orton” blur added for surreal effect, that also gives the image the ability for larger enlargements.
No Orton - “Acceptable Sharpness” up to about 11×14
Crop of the Original Photograph
“Ortonized” Image
What is your “Acceptable Sharpness”? It is a sliding scale with pixel peepers preaching the extreme sharp end of the scale, while others who create impressionistic nature shots dominating the other. Either way, this is a question for self-discovery with no right or wrong answer.
Technical Details (First Image):
Canon 5d Mark II, 70-200 f/4l @ 104mm, f/8, 1/320 sec.
Black Hills, South Dakota
This photograph can be viewed on my website at: Morning Shadows - Morning light illuminates the pine trees in the Black Hills, South Dakota
Technical Details (Flower Image):
Canon 5d Mark II, 17-40 f/4l @ 35mm, f/13, 1.6 sec.
Near Schramm State Recreation Area, Nebraska
This photograph can be viewed on my website at: Ethereal Plane - Flowers Near Schramm State Recreation Area, Nebraska