Archived posting to the Leica Users Group, 2014/03/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hmmm. Lemme check again. Could have been a cropped image I used. But my question still stands: if I double the pixels to get smothered, more realistic details as Howard stated, how do I then downsize the dimensions to retain that effect? Thanks, Bob Sent from my iPad > On Mar 22, 2014, at 4:38 PM, Ken Carney <kcarney1 at cox.net> wrote: > > Bob, > > There must be a wrong setting somewhere. I don't have a Leica M but I > imagine the file size is larger than 3352 px. My 5D II files are 5616 px. > Jeff Schewe says that upsizing to 200% is usually no problem and that has > been my experience with "preserve details" in Photoshop. The 5616 px > files are 18.7" at 300 ppi, so I could have some cropping room with modest > upsizing in PS. Lord only knows what we are talking about with your MF > gear :) or whatever the emoticon is for envious. > > Ken > >> On 3/22/2014 4:59 PM, Bob Adler wrote: >> Hi Howard, >> Trying to wrap my layman's brain around this. >> When I bring an M240 file into CC from LR with no resolution change, it >> is 2,682 x 3352 px at 360dpi. It is 7.45 x 9.311 inches in size. >> So if I use bicubic smoother and upsize the number of pixels to 2x(2,682 >> x 3,352) or 5,364 x 6,704 at 360dpi I should get the effects you are >> predicting: sharper looking images with smoother gradients BUT is now a >> 14.9 x 18.622 inch size. >> What needs to be done then if I want my print size to be at the original >> dimensions: 7.45 x 9.311 inches? Or a larger size than the now 14.9 x >> 18.622 inches? >> Thanks, >> Bob >> >> Sent from my iPad >> >>> On Mar 21, 2014, at 7:40 PM, Howard Ritter <hlritter at bex.net> wrote: >>> >>> Poking around with huge degrees of enlargement and up-sampling (but >>> perhaps not irrelevantly so for making large prints of landscapes, etc) >>> in PS with files from M9, M240, NEX-7,and D800 (not E), I found: >>> >>> 1. The D800?s 36MP FF sensor with the current Nikkor 35/1.4 at f/5.6 >>> produces conspicuously better detail near the limit than the M240?s 24MP >>> FF sensor with the Summilux 35 ASPH at 5.6 does, and the NEX?s 24MP >>> APS-C sensor (same pixel size as a 54MP FF sensor) with the kit 18-55 >>> zoom set to produce the equivalent of FF 35mm FL produces about the same >>> image resolution as the M. This is not the end-all of important sensor >>> characteristics, but it can be an important one under some >>> circumstances. What this tells me is not only that a 24MP FF sensor does >>> not put modern premium prime glass to the test, but also that even >>> inexpensive modern kit-zoom glass would not be outclassed by a 54MP FF >>> sensor with regard to resolution. This would seem exactly analogous to >>> the role of fine-grain film back in the day (anyone remember that >>> stuff?). One wonders what Leica AG (and every other manufacturer?s) >>> engineers make of this fact, and whether there is a 54MP camera (M540?) >>> or beyond in their minds. Of course, as with Microfile film, the part of >>> the "need spectrum? such capability occupies would be very small. Still, >>> Microfile had its enthusiasts beyond microfilming documents for >>> efficient filing. I?d like to know what pixel count (disregarding >>> tradeoffs in noise etc) corresponds to the innate resolving power of the >>> best modern glass at center and optimum aperture. Given the improvement >>> produced by the ~25% linear increase from 24MP to 36MP and the 50% >>> increase to (an effective) 54MP, it?s clearly at least 1.5 times, and >>> maybe twice, the linear count of a 24MP sensor (i.e., ~50 to 100MP). And >>> what pixel count corresponds to the best general-use emulsions from the >>> Age of Film (K64, Plus-X, etc) in terms of lp/mm? Anyone have a >>> reference? These results also make me wonder about the actual utility of >>> the new superpremium normal lenses, the 50mm Summicron ASPH and Nikon?s >>> 58mm 1.4, with current sensors. Maybe they extend the envelope in which >>> they are not outmatched by the sensor further from the center and from >>> the optimal aperture beyond what lesser lenses do. >>> >>> 2. Doubling the linear number of pixels H and W in PS produces a clearly >>> smoother image, with what appears to be better resolution, near the >>> limit. I know that in theory this is illusory, as creating new pixels >>> from the averages of their parent and neighboring pixels cannot add new >>> information. But the appearance of doing so is strong, and I think this >>> is a result of the fact that for the most part, natural subjects are not >>> wholly random but have fractal dimensions and high degrees of internal >>> correlation: for example, linear or continuous features are common, such >>> as areas, edges and boundaries, and so on. Such features are not likely >>> to be confined to a few pixels but to extend over many. Multiplying >>> pixels as is done in PS can create a powerful illusion of making a >>> linear feature seem better defined and sharper. If you took a picture of >>> a wall of tiny square, randomly colored tiles such that the image of 4 >>> tiles in a square exactly occupied an entire pixel, the original file >>> would make the 4 look like 1, with a color representing their average >>> (this is a thought experiment, ignoring the fact that we deal, Foveon >>> aside, with single-color pixels and Bayer patterns). Pixel-doubling >>> would then produce not a faithful depiction of the actual 4 tiles making >>> up the square, but an illusion of 4 tiles and an artificial average >>> color for each of the virtual tiles. But this is a very unnatural >>> situation, and in real life, with natural subjects, what appears at any >>> given point in an image is likely to closely resemble what appears at >>> the points that correspond to the adjacent pixels, so that >>> pixel-doubling does, in at least a semi-real sense, have the effect of >>> increasing the visual resolution of the image. I think of up-sampling >>> the original file to increase the pixel count as ?unmasking? information >>> that was implicitly there as a result of the innate characteristics of >>> the physical world. >>> >>> ?howard >>> >>> _______________________________________________ >>> Leica Users Group. >>> See http://leica-users.org/mailman/listinfo/lug for more information >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for more information > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information