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#121
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The end of the DSLR
On 5 Aug 2008 23:19:01 -0500, "Toby" wrote:
It will take a long time for EVFs to equal OVFs. LOL that's what they said about digital photography over film photography. EVFs and LCDs will indeed improve and will replace pentaprisms likely sooner than you think, the new DSLRs today already include live preview. Ron *****Boreal Photography***** http://borealphotography.com **Digital Photography Blog** http://lvsonline.com/online-digital-...raphy-classes/ |
#122
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The end of the DSLR
Scott W wrote in
: On Aug 7, 3:41*am, Chris Malcolm wrote: David J Taylor . uk wrote: You can call it what you want, but the image needs inversion before it is suitable for most of us to view..... But we must be careful to distinguish between the rotational and lateral inversions. For example, why do mirrors interchange left and right but not up and down? They don't chnage left and right, what they do change is front to back, which is what changes the handedness (if that is a word). So x and y axis stay the same but z becomes -z. I am late to this party but what the hell... Scott's three lines are an admirably concise account of what plane mirrors do. I, on the other hand, intend to run on for a bit. Concave mirrors producing a real image invert along all 3 Cartesian axes, as do lenses creating real images. Optical systems which create odd numbers of inversions create net inversion. Systems which create even numbers of inversions create images which are equivalent to a rotation plus a possible change of scale. This is of profound significance in the busines of life. Molecules which cannot be rotated into congruence with their mirror images created by a plane mirror are called dissymetric. Thus, almost all amino acids involved in protein molecules are dissymetric. Humans can metabolize amino acids with one stereochemistry at the carbon closest to the acid carbon, but not their mirror image structures. Other such selectivity occurs all through nature. One of the very earliest insights into this phenomenon came from a young lady called Alice, she of the looking glass and Wonderland. She says, at one point, "Perhaps looking glass milk is not good for you." This is a remarkable piece of thinking for the 19th century, particularly since both books were written, I think, before van't Hoff and le Bel published their separate papers on the stereochemistry of carbon. (Neither of them was the originator of the idea but their work came along at a time when the world was ready for it.) - Shankar |
#123
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The end of the DSLR
On Tue, 23 Dec 2008 01:51:39 GMT, Shankar Bhattacharyya wrote and
wrote and wrote: Scott's three lines are an admirably concise account of what plane mirrors do. I, on the other hand, intend to run on for a bit. Sometimes failing to be succinct is a virtue, as here. Thanks! |
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