Archived posting to the Leica Users Group, 2014/03/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]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