I did not read the article. I just scanned it for references and found none. Curious how someone without a mathematical background can come up with stuff like this that is nearly identical to that which has been previously been published. Perhaps he is some kind of a savant or something....
Awesome, thanks for sharing that.Originally Posted by Christopher Broadbent
That seems to produce a softening look of the image; I wonder if that can be done in photoshop (that is, the slightly softened appearance, not the dof).
Straight Gaussian blur does not look anything like lens diffraction (for example, using netting, or shooting through a very small aperture as in the example above) and yet I see this done all the time; however, you can create a very interesting soft focus effect in PS by cloning the sharp image, slightly blurring the new layer, and carefully averaging it back into the sharp image (opacity, etc.).
Example (minimal):
This definitely took the hard edges off of the glass without making it look out of focus. But to be honest, I have always preferred in-camera soft focus techniques aesthetically. I am going to play with the in-camera version of the PS technique I mentioned above by adding additional diffracted exposures to a primary sharp exposure just to see what come out the other side...
I am thrilled to learn that small apertures are effective for softening...time to experiment! I have a f/128 lens on the way to boot!
I have never concerned myself with the optical characteristics of the lens in choosing an f-stop. My definition of the optimal f-stop is simply driven by the compositional needs and once that is configured, then you can do no better with either diffraction or abrasion. It is what it is.
If DOF is the consideration, then I choose the largest aperture opening possible that will bring into focus all significant elements of the composition. If shutter speed is the consideration such as blurring moving water, then I will use the shortest possible shutter speed to achieve the effect I am looking for.
I have used aperture settings from wide open to f/128, and yes some prints are sharper then others. However, the emotional impact of the composition and ultimately the saleability of the final print far out ways any consideration for absolute clarity at all cost.
Stephen,
8x10 DOF forces us taxi-driver photographers to stop down. Otherwise we either have to move the camera back, squash the composition or use a smaller format to get it all in focus.
Why do we want it all in focus? Because we are doing our best to make pictures that do not look look like photographs. Our fares want to put stuff in their billboards, not photographs.
Christopher, Seriously. Is that a more-or-less straight photograph? Incredibly "soft" look, very painterly. Incredibly interesting look.
Christopher,
I am not sure what your point is because I do not understand your terms.
Constructing a composition is an iterative process and we make trade offs between what is possible and the ideal configuration of camera, lenses, perceptive, DOF/f-stop, shutter speed, and composition. The point I am making is that the composition is the driving force. However, quite often we must compromise the composition because the limitations of our equipment or perspective. How many times have I wished I could purchase a helicopter or how many times have I poached photographs on private land so that I could realize a better perspective for my composition.
For those who are preoccupied with absolute sharpness of image, I say that the mood and power of the composition far out ways the importance of the sharpness. Sharpness is a consideration and just using a LF camera is a big step in that direction, but sharpness with respect to optimal f-stop of a lenses is low priority for me as opposed to optimal f-stop for the composition.
For those who use 8x10, I would have no problem using smaller aperture openings riddled with diffraction if it allowed me to realize a breathtaking image. Absolute sharpness does not sell photographs. The mood and power of the composition is what sells.
Christopher, it is a beautiful still life and I can see it used in an ad campaign. But honestly, that is diffused light glowing. Look at the flatware catch light as an example. If you did not use a diffusion filter on your lens, than what did you use on your light source?
It is just a very dirty old lens. We could start a new thread "Do you clean your lenses and why not?". I could not use a black stocking because near f64 it gets in focus. Breathing on the lens only works for long exposures and this was strobe. There was a window-light plus a small beehive with an 1/4 orange gel on the same axis to pick things out with a little sunlight.
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