No, I am not. Are you? So let�s just agree - to disagree! But how many cars per millimetre did you get? Or was it pairs of cars? All the best! Raimo Personal photography homepage at http://personal.inet.fi/private/raimo.korhonen
-----Alkuper�inen viesti----- L�hett�j�: Bob Blakely <[EMAIL PROTECTED]> Vastaanottaja: [EMAIL PROTECTED] <[EMAIL PROTECTED]> P�iv�: 18. tammikuuta 2002 0:36 Aihe: Re: And did I mention wrong >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 . - 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 .
