grepmat Posted June 14, 2004 Share Posted June 14, 2004 John, I've heard that half of the U.S. population believes in alien abductions (or something like that), too. I don't know why people believe the things they do. No, I'm afraid you are not right about diffraction and interference between pixels. Scott, I can only assume you are attempting at an amusingly oblique insult. In answer I say: Maybe when you finally design a digital camera and test it extensively, you will understand what I am talking about. Doing so is my reference, not some website. You should try designing sensor arrays yourself -- it's fun. Cheers. Link to comment Share on other sites More sharing options...
aardvarko Posted June 15, 2004 Share Posted June 15, 2004 <i>Each pixel in a sensor will itself act like a lens and the interraction between those lenses will cause diffraction.....am I wrong?</i><br><br>Yes! Link to comment Share on other sites More sharing options...
john_carter_rhodes Posted June 15, 2004 Share Posted June 15, 2004 Thanks for that erudite response Chris. You've solved the whole issue now. ;) John. Link to comment Share on other sites More sharing options...
walterh Posted June 15, 2004 Share Posted June 15, 2004 perhaps it would be of great help to get some education about how current digital camera sensors are built, their design, function and structure of optical components. Since we seem to have experts in this thread, proclaimed and unproclaimed (trying to be funny here to calm things down a bit from an excitement, that seems to me primarily due to real exciting interest in the story and not personal) I suggest that everybody who has the information provides links or direct info on the topic. At least i would like to learn more about it in detail. After that many discussed effects might become more clear. Any suggestions? Link to comment Share on other sites More sharing options...
scott_blair1 Posted June 15, 2004 Share Posted June 15, 2004 <I>"You should try designing sensor arrays yourself -- it's fun."</I><P>I prefer photography. But to each his own. Link to comment Share on other sites More sharing options...
grepmat Posted June 15, 2004 Share Posted June 15, 2004 Scott, perhaps you should stick to photography, then. Your ownership of a digital camera doesn't by itself confer knowledge of its physics and engineering. Though, in true photonet style, it does seem to give you permission to denigrate other posts and posters. Walter, the purported goal of this forum is education, and that is noble one. Introductory material on CMOS and CCD sensors is out there, and individuals in the photonet community are slowly absorbing it. But unlike issues related to film, where community members are among the highest experts in the world, the average photonetter cannot invest the many years of time and considerable expense required to gain any serious depth of knowledge on digital sensors, etc. Unfortunately, there's often a curious "Ignorance is Strength" attitude here, and a little knowledge is a dangerous thing. I suppose we can hope that things improve over time, and now and then I try to contribute a tiny bit, though sometimes without much success. Cheers. Link to comment Share on other sites More sharing options...
robert_ades1 Posted June 15, 2004 Author Share Posted June 15, 2004 Can someone give me a simple answer to my question, please? Link to comment Share on other sites More sharing options...
grepmat Posted June 15, 2004 Share Posted June 15, 2004 Robert, as I mentioned above, this is not an inherent problem with digital sensors. It is almost certainly the lens, and it may be improved with a better lens such as the f/2.8 version or a good prime. Of course, better lenses tend to be more expensive and heavier. You will note that some others apparently disagree with my assessment - that's the photonet way. Cheers. Link to comment Share on other sites More sharing options...
john_carter_rhodes Posted June 15, 2004 Share Posted June 15, 2004 Robert, as I mentioned above, this is not an inherent problem with the lens. It is almost certainly the digital sensor, and it may be improved by using film, any of the films on the market will remove this problem. Of course, film processing can be more expensive, unless your DSLR is worthless in a couple of years (how likely is that?), and will give you resolution, contrast, latitude, and more that digital can never manage at this time. You will note that some others apparently disagree with my assessment - that's the photonet way. Cheers. Link to comment Share on other sites More sharing options...
scott_blair1 Posted June 15, 2004 Share Posted June 15, 2004 <I>"Can someone give me a simple answer to my question, please?"</I><P>No, Robert, nobody here can. The blunt truth is that you are going to have to solve this on your own. There have always been combinations of camera, lens, film, and now digital body, that can give unique results for different users and shooting styles. You will simply have to evaluate equipment first hand. Even then, you may uncover quirks of that equipment in the future as you encounter different situations. It was not a stupid question; to your consternation, and ultimate benefit, only you can answer it. And you don't need to know jack about the science of it to know your gear and how to get the best results from it. But somebody, somewhere, will try to lead you astray by discounting the value of experience. Link to comment Share on other sites More sharing options...
grepmat Posted June 15, 2004 Share Posted June 15, 2004 Robert, it seems that John the droll troll, who couldn't answer your question without raising the old film vs. digital canard, unintentionally pointed out one interesting path. Put your lens alternately on a film camera with some fine grained film and your digital, shoot the same contrasty scene with some nice sharp bright/dark transitions for both, etc., scan the film at high resolution, and post examples of the paired images here. By the way, shots from the D70 with 18-70mm lens shows no significant CA - certainly much less than your photos show - at 18mm or any focal length. You might want to consider that lens, as it's a great companion to the D70. Cheers. Link to comment Share on other sites More sharing options...
grepmat Posted June 15, 2004 Share Posted June 15, 2004 On second thought, I apologize for the "droll troll" comment, John, though for someone who apparently knows little to nothing about sensors and is just parotting others, you seem supernaturally sure of yourself. Have a nice day. Link to comment Share on other sites More sharing options...
john_carter_rhodes Posted June 15, 2004 Share Posted June 15, 2004 I am indeed sure of myself, as we all should be. However I'm not sure about everything, unlike you, Grepmat. Given your superior knowledge, perhaps you'd like to predict the date of the end of the universe? Personally, I'd never try to close a line of an argument without hearing the reasons for it, but 'HEY!', if you know everything, then 'GO GIRL!!!' John. Link to comment Share on other sites More sharing options...
robert_ades1 Posted June 16, 2004 Author Share Posted June 16, 2004 <<Put your lens alternately on a film camera with some fine grained film and your digital>> John: Actually, check out these shots taken on my FE2, at 18mm, f/8.0, Gold 200 (it's all I had), scanned at 2000 dpi, 14-bit/channel. http://www.pbase.com/image/30217093 http://www.pbase.com/image/30217094 and remember this one on the D70 shown above: http://www.pbase.com/image/30076493 Link to comment Share on other sites More sharing options...
aardvarko Posted June 16, 2004 Share Posted June 16, 2004 John, seriously, you have some real misconceptions about microlenses on CCD/CMOS arrays. Diffraction within the microlenses has nothing to do with it, because there is none. A lens will exhibit just as much chromatic abberation on a film body as on a digital body. Link to comment Share on other sites More sharing options...
john_carter_rhodes Posted June 16, 2004 Share Posted June 16, 2004 Thanks Robert. Interesting comparison. Looks like the lens might be the issue in this case. Chris, I agree that a particular lens will display similar chromatic aberration on film and digital, but the digital sensor WILL introduce aberrations of its own. These are easily fixed in PS, so I don't know why you're all so concerned about it. Just live with what you have and get over it. :) John. Link to comment Share on other sites More sharing options...
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