Abstract Thoughts & A Depth-of-Field Lesson « Arthur Morris/BIRDS AS ART

Abstract Thoughts & A Free Depth-of-Field Lesson

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This is a crop of the abstract image from the last post here. Canon 800mm f/5.6L IS lens, the 1.4X II TC, and the EOS-1D Mark IV. ISO 400. Evaluative metering -1/3 stop: 1/500 sec. at f/10.

Abstract Thoughts

When I asked “Like it or Hate It?” in the last post here, I never expected such overwhelmingly negative responses; 4 for delete, 1 ambiguous, 1 OK “but only because I have been there,” and 1 sort of liked it. The image was received quite differently in my BPN thread that featured the same image: Seven loved the image and found it interesting and provocative. Zero hated it. You can see that thread here. Thanks to Marina Scarr for suggesting a crop from the right in Pane 10 there. The opening image here is similar but not identical to Marina’s crop.

Several folks stated or implied that they would delete the image because “they did not know what it was.” Jeez, I thought that that was the point of an abstract….

From Dictionary.Reference.com: abstract (adj.)

Fine Arts

a: of or pertaining to the formal aspect of art, emphasizing lines, colors, generalized or geometrical forms, etc., esp. with reference to their relationship to one another.

Go figure.

And oh, by the way, I liked the original but I like the repost above even more πŸ™‚ No hard feelings though. (I never take it personally.) Heck, the last time folks were so vehemently against an image that I liked we sold it for $700 to Oprah magazine. You gotta love it.

Larry Warfield wrote, “I generally like the pattern, but the white on the right hand edge and the portion of the wing on the left hand edge keep distracting my eye from the interesting triangular pattern. I also wish the back was a little more in focus. That being said, it’s easier to be a critic that an artist. I wish I could take something, at all close to that good. Nice shot.”

The crop from the right takes care of the white. I too wish that the back were a bit more in focus but pelicans are very large bird and depth of field is quite limited with big lenses near minimum focusing distance. A quick visit to DOF Master revealed that with a focal length of 1200mm (the closest drop down menu value to 1120mm) and an aperture of f/11 (that’s what I used to create this image) that the total depth of field would be .36 inches, less than 1/2 inch. If I dropped down to f/22 the total depth of field would increase to .72 inches (just a shade less than 3/4 inch). That means that I would have gained .18 inch behind the neck (that’s where I focused) and .18 inch in front of the neck, i.e., the back. So stopping down from f/11 to f/22 would have gained only a fraction of an inch of extra d-o-f, not nearly enough to render the back feathers in sharp focus. Those back feathers are several inches closer to us than the neck….

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This is a screen capture from DOF Master. Be sure to bookmark the site but only if you want to learn a ton about depth-of-field with various focal length lenses…

Shopper’s Guide

Below is a list of the gear that I used to create the image above. Thanks a stack to all who have used the Shopper’s Guide links to purchase their gear as a thank you for all the free information that we bring you on the Blog and in the Bulletins.

Canon 800mm f/5.L IS lens Right now this is my all time favorite super-telephoto lens.
Canon 1.4X II teleconverter This is my most used accessory; I would be lost without it.
Canon EOS-1D Mark IV professional digital camera bod.y And this is the very best professional digital camera body that I have even used..

And from the BAA On-line Store:

Gitzo 3530 LS Tripod This one will last you a lifetime.
Mongoose M3.6 Tripod Head Right now this is the best tripod head around for use with lenses that weigh less than 9 pounds. For heavier lenses, check out the Wimberley V2 head.
Double Bubble Level You will find one in my camera’s hot shoe whenever I am not using flash.
Delkin 32gb e-Film Pro Compact Flash Card Fast and depen.

If you are considering the purchase of a major piece of photographic gear be it a new camera, a long lens, a tripod or a head, or some accessories be sure to check out our complete Shopper’s Guide.

8 comments to Abstract Thoughts & A Depth-of-Field Lesson

  • Art, since when you posted a question about the DoF in the gull+pelican photo, I was going to ask you something about and waited for a proper post.

    Simply put, my question was: how often do you use f/22 (and smaller) in a long tele shot? Usually, I never go beyond f/11 or f/16. More than one year ago, I run into a beautiful subject with two sanderlings sleeping in the foreground and one dunlin in the background. Indeed I was near to a flock of birds, down on the sand, with the sun in good position and a good way to stabilise my long lens. I shot hundreds of photos and most of them (simpler subjects, such as one bird at a time) were fine (sharp, etc…). With the “two sanderlings + dunlin” subject I knew that it was impossible to get everything sharp, but I wanted to have the dunlin in the background less blurred as possible. So I went for f/40 (which was the smallest aperture given by the lens + multiplier). The image didn’t get as sharp as the others, of course, I suppose because of diffraction (and also because sometimes I don’t feel confident in myself, so I kept 1/160 sec. and consequently ISO rose up to 720, giving more grain and less detail). The dunlin was deeply blurred, anyhow.

    So, I’m always questioning whether it makes sense to try such a shot, that perhaps is just impossible…


  • avatar Arthur Morris/BIRDS AS ART

    Bryan, You are on the right track. Additional great advice: always focus on the subject’s eye and let the rest fall where it may. And yes, differences in d-o-f with different cameras are a result of the differing crop factors of the cameras. See you on BPN πŸ™‚

  • One more question, and this might seem really obvious so forgive me. On the DOF calculator, I assume the distance changes from a 50D to a Mark III because of the crop factor, correct? If not, please help me to understand that. Thanks.

  • Artie, thanks for the DOF bookmark suggestion. I knew working with my 600mm + 1.4TC had a shallow DOF, but this really drives home to me the emphasis on where I need to focus depending on the distance from the camera (not a lot of wiggle room). Hopefully this information coupled with the tutorial on micro adjustments will give me the fine tuning I need to be more consistent with sharpness. Thanks again. Great stuff in your blogs.

  • avatar M. Bruce

    Art – Thanks for the Depth of Field calculator link – very informative. But as I learned many years ago, there is only one sharp and then degrees of acceptable which can be up to individual interpretations and desires.

  • avatar Eleanor

    Artie, I think this crop would be a better abstract if it was cropped again to the top of the bird’s wing making it square. All the elements are then contained and relate to each other. You then have line, texture, and positive and negative space.

  • avatar Arthur Morris/BIRDS AS ART

    Hey Becky, At least you sort of like it πŸ™‚

  • Artie, I hope you sell it for lots of $$$$ and prove us all idiots. :o) What do we know!?