Archived posting to the Leica Users Group, 2014/03/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Dang I only wish I understood what you meant in all that strange language and maybe I would become a "better printer?" :-) But I figure so far when people near pee their pants looking at my prints of late. And the new photography of Ted Jnr with an IPHONE. Dang it's unbelievable Number 1 Son Ted jnr. (by the way he hates that as he's 60 years of age with 2 boys of his own.) :-) Ted jnr.? But he has been shooting a series on our city on his limitd free time. PURE MAGIC! Yes I will up load some shortly and completely blow you all away! ;-) Don't you hate it when I do that? ;-) Sorry Hoppy I truly wish I understood all the cool things I know, you know! :-) cheers, Dr. ted :-) ----- Original Message ----- From: "Geoff Hopkinson" <hopsternew at gmail.com> To: "Leica Users Group" <lug at leica-users.org> Sent: Saturday, March 22, 2014 6:13 PM Subject: Re: [Leica] Random observations on resolution (long and irrelevant to the craft of being a good photographer) > I'm not convinced on this sampling voodoo! I also want to sit down and > counsel you on the errors of your ways regarding pixels per inch and dots > per inch...but I think I hear Dr Ted approaching! Just before I get > slapped > on the back of the head... > Gaah! My model booked for this afternoon just cancelled due to illness so > I'm back on keyboard. > No you mean pixels per inch for the resolution. But resolution is > irrelevant until you choose a physical size that you want to print. Up or > down sampling matters to make a say 24MP image a 12MP or a 36Mp or > whatever. You can make up new data or throw away data but it is > independant > of resolution. The 360DPI 'standard' for printing comes from circle of > confusion theory and theoretical printer native capabilities. Hower ink > jet > printers do not just make one size, one tonal value. one colour one fixed > DPI patterns in any case. They make variable sized, toned and coloured > overlapping/variably spaced patterns. Trust me, let LR do the math for > you > (whether letting it select suitable ppi for you or resampling to fixed > value you choose) for your physical print size ;-) > > Slap! Ouch sorry doctor, I'm outta here! > > > Cheers > Geoff > http://www.pbase.com/hoppyman > > > On 23 March 2014 09:52, Robert Adler <rgacpa at gmail.com> wrote: > >> Geoff is correct with pixel dimensions; I must have been looking at a >> cropped image. Question still stands though... >> >> >> On Sat, Mar 22, 2014 at 4:45 PM, Bob Adler <rgacpa at gmail.com> wrote: >> >> > 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 >> > >> >> >> >> -- >> Bob Adler >> >> _______________________________________________ >> 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 --- This email is free from viruses and malware because avast! 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