Black and White Photography Blog, Vol. I

“Dave - One thing I find fascinating about these new pictures is just how sharp they are from foreground to background.

Compare them with the image of the wheel on the header and the difference is striking. It’s as if depth of field doesn’t exist, at least at this magnification.

Is this due to post shot processing?” - Stephen

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Not due to post processing. Due to the angle of the shot and to some extent the DOF of the 20mm; and the distance to the nearest object. But the high angle changes the ratio of distance between the near and far objects. In other words, picture the camera at eye level. Think about the distance between the cabs in the foreground and the Apple store. Them imagine the camera up in the air 20 feet. All of a sudden you’ve added a substantial distance between the objects in the “foreground,” they’re now at the bottom of the frame, and in the distance, and both are well within the DOF of the 20mm and the same effect will work (to a lessening effect) as the lens gets longer.  In short - if you think about how DOF works - the closer the object, the narrower the DOF.   If the camera is a foot away from the subject at a given F-stop, you may find that focus is narrow.  The difference of a few inches at a given F-Stop will throw the subject out of focus.

Same subject, but now at 10 feet, and a few inches one way or the other won’t effect the focus.  So, I’m not sure if I’m explaining this well - but by raising the camera and increasing the distance between the near object, you can get it in focus as well as the furthest objects.  One thing I don’t know how to do is increase detail or modify focus in post-processing.

If you look at the photos of Andreas Feininger that were shot with a fairly long telephoto lens (Lunchtime Fifth Avenue) - you can see a similar effect since the camera is high enough so that he can mostly keep the foreground and background in focus. He had the added ability to do shifts since he was using a view camera; nevertheless, if you put a telephoto lens on a camera and shoot down fifth avenue at ground level, you’ll find it very difficult to get the foreground and background in focus. The higher you raise the camera, the easier it gets to have foreground / background in focus.