Are you some reincarnated version of "The Who" - and I'm not talking about the band?
From: "Raimo Korhonen" <[EMAIL PROTECTED]> > You still do not seem to get my point. I did not express myself clearly enough, sorry. > "Automobile edges" - show me one automobile with really sharp edges. 1. Point your face toward any automobile. 2. Note that there are photons comming at your (I'm beginning to think blind) eyeball. 3. Some photons are comming from the background. 4. Some photons are comming from the car. 5. There photons from the car and the photons from the background form a sharp line on your retina. Or they would if your eye's lens was perfect. 6. The same thing hapens in a camera. 7. In other words, there is a sharp demarcation between car and not car. If you do not understand this, there is no hope for you. > "For measurement we create lines" - these are not infinitely thin No one said anything about the lines being infinitely thin. > but have edges and the edges are not absolutely sharp. Yes, but they don't have to be. They just have to be significantly sharper than the resolving power of the lens. > Then you say that MTF "is just a single point solution to the modulation transfer function where contrast = 0". Yes. > Indeed! Yes. > That was my original point: you cannot separate resolution and contrast. Since no one has tried to separate resolution and contrast, what the hell's your point? > And in a real world you cannot separate your edges and lines with a contrast much higher than 0. We have equipment that performs these separations all the time with contrasts very close to 0. > , the article you mention gives the limit at 20% - like in a photographic negative, print or slide. That is for the equipment and materials you can buy. > And the higher the contrast the more lines you can discern - visually or with any kind of equipment. Bullpucky. There are other limits besides contrast. Let's see, oh yeah, anything that creates dispursion like the diffraction limit, or poor glass, or poor element alignment or bad focus. Increase the contrast all you want, they'll not give you any better resolution than the limits they impose. > And if we talk about "some silly notion about fuzzy molecules on the surface of the object" that�s what your lines - e.g. on a test target - are if we are talking about 200 lpm. Bullshit. Are you a sophmore at some high school? Bob... - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
