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#61
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"rafeb" wrote in message . com... C J Campbell wrote: In what way is it better? Why does the small sensor of the human eye have better resolution than the large sensor of a 35 mm frame? The human eye has this thing called a brain behind it. The human eye has great resolution over a very small viewing angle. But the brain can direct that super-sensitive area (the fovea) instantly to where it's needed. That explains absolutely nothing. You are saying that the human eye performs better, despite its deficiencies, because it has better software? Well then, why can't better software improve the picture on a small digital sensor? In many ways the human eye is a pretty poor design. Light actually has to pass through a layer or two of neural processing tissue before it lands on the retina! The eye in this respect is nothing but an extension of the brain. Rods provide very rough resolution, but tremendous light sensitivity, reacting to a single photon. The individual rods, however, are poorly connected; often three or four rods connected to a single pathway. This inefficiency is probably an advantage in helping to reduce noise. |
#62
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"Roger N. Clark (change username to rnclark)" wrote in message ... Consider the "sensor size" of the eye of an eagle, or even a human eye, and the relative quality of that sensor vs. any camera or film. (I suppose a human eye could be defined as a 150 MP sensor, but only about 16 MP are used for color vision -- the rest simply give a rough outline of light and dark. One may note, too, that small children, whose eyes are not fully developed, may still "see" something like digital noise, which disappears at about age 5 or so. The physical size of a human eye is not all that large; the eye of an eagle is much smaller yet sharper with better color vision.) I wonder how much the image recorded by the eye could be enlarged before you began to see significant degradation, but I digress. And not factual either. The human eye with normal vision has a image resolution equivalent over 500 megapixels. See: http://www.clarkvision.com/imagedeta...esolution.html Does it indeed? So how does the eye achieve that resolution with only 6 million cones and somewhere between 100 million and 200 million rods -- most of which are duplicates or not connected to anything? Maybe Mr. Clark needs to check his figures again. |
#63
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rafeb wrote: Mostly what I thought we were discussing is whether 100% viewing on screen was useful or not. I maintain that it is, for critical work, or for large prints. In my experience -- while the print is the end goal, the monitor is a pretty good predictor of how good the print can be. If detail or tonality aren't there on the screen, they're not going to magically appear on the print. The problem is that it is easy to fool yourself into thinking there is useful detail in a photo when there is not, when viewing it at 100% on screen. The reason for this is simple, at 100% on screen you will see low contrast detail because it will be fairly low in lines per inch, but when printed this low contrast detail is no longer visible to the human eye. The eye can see detail to 0.7 line pairs per inch for 100% contrast, at a light level of 23 foot lamberts, this drops to 0.4 line pairs per inch at 10% contrast. And you can see down to less then 2% contrast if the line pairs per inch are at 0.1. What all this means is that you will see detail on the screen that you will not see in the print. So you are correct detail will not magically appear when printed, but it will disappear. Scott |
#64
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On Tue, 22 Feb 2005 23:47:26 -0800, "MarkČ" mjmorgan(lowest even number
wrote: This is why I think anyone considering spending with[in] a few hundred dollars of the 300D or D70 on a lesser...but sizable camera...should REALLY consider teh DSLR. It really can open new visions for people when they experience the difference...without having to magically "miss things" they have never even experienced. I was in exactly this situation. I had a compact zoom film camera and wanted to "go digital" (well, go "properly" digital -- I did have a few-years-old 1+MP p&s, but I'd stopped using it). Probably the main criteria was to get something "pretty decent" that would do most of things -- at least reasonably well -- that I'd be likely to want to do for some time to come. For little more reason than I spotted a second-hand one in a shop, and it looked "nice", I originally started looking at the Nikon 8700. Browsing around the web, I was then toying between it and the 8800 (it cost more, but had stabilisation). Almost on the verge of buying one or other of these, I then stumbled across (among other sites) one of Ken Rockwell's pages where he basically said the same as you: If you're going to spend your money on [any of the 4 or 5] 8Mp prosumer fixed-lens cameras, you're probably better spending a little bit more and getting a lower-end dSLR (better noise, startup- and shooting-speeds etc.). In my particular case, I also went with his (and others') opinions of the D70 being preferable/better to the dRebel, but this isn't a Canon v. Nikon argument -- the important issue is high-end p&s v. low-end dSLR. Although I've not had as much chance to do as much shooting as I would like to yet, I'm convinced I made the right choice. The D70 (in my case) allows much greater freedom for whatever directions my future photographic desires will take me than one of the high-end p&s would have done. I may never use all the potential, but at least I know it's there! Regards, Graham Holden (g-holden AT dircon DOT co DOT uk) -- There are 10 types of people in the world; those that understand binary and those that don't. |
#65
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Chris Brown wrote: In article , rafe bustin wrote: On Wed, 23 Feb 2005 13:41:27 GMT, Owamanga wrote: At the very least, you should be using a large format film camera. I do that as well. It puts these puny 6 Mpixel DSLR images in perspective. I gave it and bought one last weekend. It's a great old thing, MPP VI, upgraded to VII spec with the rotating international back. Two days ago, I shut myself in my bathroom, blocked the gap under the door, turned out all the lights, and loaded my first sheet of film. That was a bit of an intimidating experience - I knew vaugely what to expect after unsealing the box, but having to do it all in total darkness by feel alone was kind of daunting. I'm hoping it'll get easier with experience. I also got a rollfilm back for 6*7, for when I'm feeling too wimpy to use sheet film. So far, I have spent hours playing with the camera, but have yet to take a single exposure. How many digital cameras can you say that about? ;-) I expect I'll be taking a picture this weekend - probably a macro of a dried flower using the triple extension. I'm hoping my friendly local lab won't mind me just dropping the dark slide off with them, otherwise I have no idea how I'm going to get this processed. I don't especially fancy setting up my own E6 darkroom. My wife has decided that we are calling the camera, "Snapper", because something with so much character needs a name. This is not because we expect to use it to make expensive snapshots, but because the thing essentially seems to be a load of springs held in formation by willpower, which leap out and "snap" at the unwary. Not entirely sure what I've got myself into here... Keep me posted on your travails... by private email if you like. I'm all over the map with my camera gear, it mostly depends on how much schlepping I'm willing to do at any given moment. LF is definitely max-schlepping. rafe b. http://www.terrapinphoto.com |
#66
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Owamanga wrote: There's nothing overly wrong with occasionally critiquing at 100% or more if the possible destination print dimensions require that, but in many cases it's like a bank teller who uses an electron microscope to check your signature. A fine waste of time. For 4x6" prints, most definitely a waste of time. Maybe even for 8x10". At this point I've sold a good number large-ish prints (20x30", 24x36") that formerly I'd only done at 8x10 or 12x18". I'm getting enough $ from these to where I think my on-screen viewing time is well justified and properly compensated. rafe b http://www.terrapinphoto.com |
#67
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On Wed, 23 Feb 2005 11:18:34 -0500, rafeb wrote:
Owamanga wrote: Agggh! but the whole point of capturing the image (in *most* people's use of a DSLR) is to PRINT IT. Well, actually a lot of folks claim that they're not interested in prints, but rather in seeing their images on a CRT. I'm not one of those, but it's yet another way of "seeing" things. As far as I know, as yet, no CRT or LCD has a 6Mpix resolution. I guess it won't be long, but right now that's a pipe-dream. At 100%, on an average screen at 1280x1024, you can see about 1/5th of a 6Mpix image. This is what they are striving for? Really? Or is it more realistic to presume they want the entire frame to *fit* within the resolution of the display device (would make sense wouldn't it). In which case we need no more than 1.3Mpix. Again, especially for these people, it comes back to the fact that it's *pointless* critiquing this stuff at even 100%. Yes, gamut gets compressed, yes data gets discarded, yes the frame gets cropped slightly, yes a paper texture is introduced, yes reflected chemical or pigment prints look different to backlight-screen images. But we *accept* all of that because the final product IS THE PRINT. ..if we can't see the defect in the print, then there *is no defect*. Seems like a narrow point of view, but maybe OK for "99.9% of users." Okay, I'm coming down harder on this than my real opinion, (which is somewhere in the middle) to demonstrate a point in black & white. This argument presumes that printing technology is static (and this includes printer, papers, and ink) or that your printing skills are static, or that you'd never want to see the same image in a larger print. ...which I believe, realistically describes the dreams and aspirations for 99% of the photos the current user base prints. I've been involved in the "digital darkroom" for about seven years now. I started out having great fun scanning 35mm film and making 8x10" prints on an Epson 600. Okay, I've been doing it for about 10 years, with the help of Kodak's Photo-CDs, but only started scanning my own slides about 3 years ago and then gained the ability to go fully digital about 6 months ago. At this point I'm shooting everything from 35mm, a 10D, a G2, MF and LF film, and printing on an Epson 7000, or LightJet, Chromira, or Durst Epsilon. Maybe someday I'll have an Epson 9600 or a Roland or Colorspan... who knows where this insanity will end? My 10 year old Photo-CD images are still of high enough resolution for an 8x10 on the best of today's commercial printers. Anyway, *then*, when you finally have this superb printer that can do 5ft by 3ft prints, and you've got some damn big walls to hang the stuff on, and you've found a framer who can put it behind glass for less than $200 a throw, I'd say sure, go ahead, critique anything you plan on sending it at 100% or more - it'll be time well spent. But today, this just isn't realistic. Even then, I'd question the need for the image to be good enough to stand up to inspection from 15" away (as you do your screen today). When I look at paintings or photos that size in exhibitions, I would usually to maintain a distance of at least 5ft. So, critique your screen work at a distance of 5ft and now you are being realistic. -- Owamanga! |
#68
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Graham Holden wrote:
[] For little more reason than I spotted a second-hand one in a shop, and it looked "nice", I originally started looking at the Nikon 8700. Browsing around the web, I was then toying between it and the 8800 (it cost more, but had stabilisation). Almost on the verge of buying one or other of these, I then stumbled across (among other sites) one of Ken Rockwell's pages where he basically said the same as you: If you're going to spend your money on [any of the 4 or 5] 8Mp prosumer fixed-lens cameras, you're probably better spending a little bit more and getting a lower-end dSLR (better noise, startup- and shooting-speeds etc.). This is only true, though, if you are prepared to accept the penalties of interchangeable lenses, dust, size, cost, bulk, weight etc. of the multi-lens DSLR solution. It depends on many factors including your photographic needs and aims. One solution doesn't fit all. David |
#69
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Owamanga wrote:
[] As far as I know, as yet, no CRT or LCD has a 6Mpix resolution. I guess it won't be long, but right now that's a pipe-dream. 9MP monitors are already available... http://www.pc.ibm.com/us/intellistation/t221/ David |
#70
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C J Campbell wrote: "rafeb" wrote in message . com... C J Campbell wrote: In what way is it better? Why does the small sensor of the human eye have better resolution than the large sensor of a 35 mm frame? The human eye has this thing called a brain behind it. The human eye has great resolution over a very small viewing angle. But the brain can direct that super-sensitive area (the fovea) instantly to where it's needed. That explains absolutely nothing. You are saying that the human eye performs better, despite its deficiencies, because it has better software? Well then, why can't better software improve the picture on a small digital sensor? Maybe someday it will... by waving the sensor around under the lens. But prints-on-paper or images-on-screen are a qualitatively different thing from human vision (as if that even needed saying.) In many ways the human eye is a pretty poor design. Light actually has to pass through a layer or two of neural processing tissue before it lands on the retina! The eye in this respect is nothing but an extension of the brain. Rods provide very rough resolution, but tremendous light sensitivity, reacting to a single photon. The individual rods, however, are poorly connected; often three or four rods connected to a single pathway. This inefficiency is probably an advantage in helping to reduce noise. Not sure why you're making this argument. These are the reasons why photography is different in a hundred ways from human vision. They've been written about and documented extensively, not only by physiologists but by any number of photographic experts. Fascinating topics, for sure, but far beyond what I've got time for. rafe b. http://www.terrapinphoto.com |
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