Archived posting to the Leica Users Group, 1997/02/25
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]> > The decisive moment is based on eye-brain-finger-mechanical linkage timing. > top cameras. I postulate that > the electro-mechanical operation of electronically controlled cameras will > be longer than the old Leicas.... I don't see why an electronic shutter would be any slower. There is even the potential of *slightly* quicker response since a mechanically controlled shutter has to overcome the momentum of gears which can be mostly eliminated in the electronic shutter. I think the humanoid operating the camera has a far greater variability in response time. Typically a person has a reaction time of 0.3 seconds, but this can vary a bunch. A good photographer will know her/his equipment and anticipate appropriately, thus capturing the moment. Having said that, my preference is for the M4P over the M6. I want a Leica with NO electronics, not even a meter. I tend to use the zone system (or a variation for color), and either meter every shot carefully with a 1 deg spot, or meter the general lighting (incident like), set the camera, and shoot away. For me the M6J should be available without a meter, and at a fair price (M4J?). be overcome> > On a side note on all digital cameras.... > All digital cameras will have very fast response times, but there will be a > difference from say the first pixel on the top left to the bottom > right..... unlike shuttered cameras which expose the film at one time, > digitals will have a sequence of pixels over time....let me explain another > way.... > Remember the picture of the race car passing in front of a tripod mounted > camera without pan? The car gets either elongated or fore-shortened > dependent on the shutter's direction of travel relative to the car's > direction. > The way to "fix" the problem is to pan or to use a higher shutter speed... > the problem still manifests itself, but is reduced. > Now in digital photography, the image will be distorted in a parallelogram > fashion.....top left pixel will be taken first, followed by that row, go > down a row and back to the left, continue.....and this will not change with > shutter speed. Well, I hope you realize that FOCAL PLANE shuttered cameras do NOT expose the entire frame at once, hence the race car (which does seem to have a trapezoidal shape with a vertically traveling shutter). CCDs are exposed with an integration time that does act like a shutter. I'm not sure of all digital cameras, but usually the CCD is 'exposed' all at once and the scanning is to burp the data into the storage medium (and the scanning part can be slow, but the image has already been captured on the CCD quickly). The integration or exposure can be on the order of a few milliseconds (4 ms = 1/250 sec). Some high resolution digital backs (MF/4x5) are scanning in the exposure process. This is so you can get monster images (8k x 10k or 80 million pixels) using line scanning technology, since the largest commercial CCD matrix arrays are only 3k per side, and very expensive. Paul. >