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Pixel Peeper Anomalies - They're Totally Missing the Big Picture
Brad Sanborne wrote:
On Thu, 27 Aug 2009 00:40:50 +0200, Wolfgang Weisselberg Brad Sanborne wrote: On Sat, 22 Aug 2009 04:44:31 -0500, Brad Sanborne wrote: Do the math on how much magnification you are seeing by viewing a 3648 pixel-width image from a 10-megapixel camera on an average 96-dpi LCD monitor at 1:1 resolution. That's like looking at a negative with a 38x-power dissecting microscope. Correction. Let's for the sake of argument take a 10-megapixel P&S camera at 3648 pixels wide and a sensor width of 5.75mm. That's 634.5 pixels per mm. That's 16,116 pixels per inch. On a 96-dpi monitor viewed at 1:1 that's like looking at a negative with a 168x microscope. Let's for the sake of the argument not forget that the standard size one looks at through the loupe is not a 4.31x5.75mm, but a 24x36mm frame (for common compact P&S cameras), if not larger (for less P&Ssy cameras). So it's 101.3 pixels per mm equivalent and thus 2574 pixels per inch equivalent. On a 96-ppi monitor: 27x equivalent. Or how about a 15.1 megapixel dSLR at 4752 pixels wide and a sensor width of 22.3mm. That's 213 pixels per mm. That's 5,410 pixels per inch. On a 96-dpi monitor viewed at 1:1 that's like looking at a negative with a 56x microscope. Nope: 132 p/mm = 3.353 p/in = 35x --- assuming a 35mm would have held 15MPix of data and little enough grain for a matching enlargement. Now why on earth did you do all that math over when the same calculations were already done in the last paragraph? Because your's were wrong. 29x != 27x (actually 26.8111...x) and 36x != 35x (actually 34.952x). Only you did them in error. I did? Really? The width of a 35mm film frame is 36mm. That must be the reason why I wrote "24x36mm frame". That must be the reason why I calculated 3648 p / 36 mm ~= 101.3 p/mm ^^^^^ 4752 p / 36 mm = 132 p/mm .. ^^^^^ Oh, did you think "assuming a 35mm [negative] would have held 15MPix of data [...]" had to be "assuming a 35mm [width] would have held 15MPix [...]". Why on earth would one think a one-dimensional *length* could hold 15MPix? Why on earth didn't even check the math? How on earth did you come up with the wrong answers --- and differently wrong answers for each calculation? Do you always like making a fool of yourself so publicly? Yes, I love doing that, especially as it turns out you're wrong and I am right. Maybe you just have an OCD involving mathematical masturbation. Maybe you just don't grasp math. On Sat, 22 Aug 2009 05:13:32 -0500, Brad Sanborne wrote: Even if we take a 36mm width as a standard 35mm-film frame for a virtual equivalent negative-size for both, then the P&S image is being viewed with a 29x magnifier and the dSLR image is being viewed with a 36x magnifier when viewed at 1:1 on a 96-dpi monitor. Yep, wrong as it comes. -Wolfgang |
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Pixel Peeper Anomalies - They're Totally Missing the Big Picture
Wolfgang Weisselberg wrote:
Brad Sanborne wrote: Now why on earth did you do all that math over when the same calculations were already done in the last paragraph? Because your's were wrong. 29x != 27x (actually 26.8111...x) and 36x != 35x (actually 34.952x). So does this in anyway change his point? In fact IMHO you make it for him! :-) Stephanie |
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Pixel Peeper Anomalies - They're Totally Missing the Big Picture
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