I haven't written much lately as I have been busy. Today Alexis went to Primary Children's Hospital for surgery to remove her tonsil and adenoids. Usually this is not a big deal, but because Alexis is the worlds smallest 7 year old and has some unique physical problems. Like not having her head attached to her neck and Basilar Invasinaition [not sure of the spelling] this is what killed Dale Earnhardt. She also had a cold with a rattle in her lungs before the surgery. The Doctor mentioned that the surgery could cause other complications. It was decided to go ahead with the surgery as the benefits far out weighed the possible bad things that could happen. Anyway to make a long story short the surgery went great and she came through with flying colors. Now to what all this has to do with my subject line. First of all I am not near as literate as Mr. Crosby and Mr. Buck after all I am just an ignert ol' hillbilly, so I am just going to stumble along not knowing where this will go. Yesterday I received my latest issue of Road and Track and I took it to the hospital to read in the waiting room. On page 6 and 7 is a photograph that R & T is selling. See first photo. This photo was taken at Laguna Seca this fall. It is a pan blur shot with the p.o.f. [point of focus] on the rear of the Flying Lizard Porsche which is following a Ford GTR. As you look from the rear of the Porsche forward the subjects get more and more out of focus. The photographer used ISO 50, and a shutter speed of 1/20 of a second at f18. I looked and looked at this photo and tried to figure out what was going on between the lens and the camera. we all know that f stops affect depth of field, but I believe that under the right circumstances shutter speed also affects depth of field. I'm not sure why, but I'm going to give it my 2 bits worth. This effect only works in certain angles. Doing a pan shot where the object is roughly 90 degrees from the camera doesn't do this. Now go to my great piece or art work, the second attachment. Figure A: Shows the 90 degree angle shot with the p.o.f on the center of the car. The right and axis of the object are not much greater distance from the camera as p.o.f therefore the entire car is in focus. Figure B. The p.o.f. is on the very front of the first car and the left axis is within normal focus depth of field. The problem seems to arise [in this case] on the right axis which extends back to the rear of the second car. Figure C. This is sort of hard to 'splain but here goes. You are looking through the view finder, the center is the p.o.f., the rings are .....just distance from the center point of focus. My thinking is that the brain of the digital camera thinks from the center [p.o.f.] out, therefore at slow shutter speed the camera is taking its own sweet time in exposing and focusing. Like I said I'm just a silly ol' ignert hillbilly. You guys are a whole lot smarter than I am, you tell me what's going on. I do not see this effect on similar angle shots at fast shutter speeds. Check out some of the other photos of Road and Tracks web site. www.roadandtrack.com/focalpoint<http://www.roadandtrack.com/focalpoint>. My head hurts I'm going to bed.
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