blado Posted December 13, 2006 Share #1 Posted December 13, 2006 Advertisement (gone after registration) These are 100% crops from the lower left of two experimental images taken in extremely low light with the EV cranked way up later. I guess this is a string of bad pixels? Oddly, I only see remnants of it in regular images. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/11280-m8-pixel-line/?do=findComment&comment=117543'>More sharing options...
Advertisement Posted December 13, 2006 Posted December 13, 2006 Hi blado, Take a look here M8 pixel line .... I'm sure you'll find what you were looking for!
Riley Posted December 13, 2006 Share #2 Posted December 13, 2006 well that really is odd odd too are the preceding dark pixels is there anything visble on the sensor the line is absolutely straight when magified there are a few 'holes' in the line too Quote Link to post Share on other sites More sharing options...
blado Posted December 13, 2006 Author Share #3 Posted December 13, 2006 I can't see anything on the sensor. These were really weird shots, mind you, taken in 'no light' conditions, and the line only appeared after rigorous post-processing. But it is there! Quote Link to post Share on other sites More sharing options...
gravastar Posted December 13, 2006 Share #4 Posted December 13, 2006 It's a leaky or "hot" area in the sensor marked by the cluster of black dots at the end of the white line. Charge (the image) is transferred out of the array from the bottom to the top. Image information upstream from the defect tends to be swamped by the leakage giving rise to a white line with some residual information. The image signal downstream from the defect is not corrupted and is read out normally. The leakage must be small compared to a normal signal, the defect is not visible under more usual operating conditions and some noise does appear to transfer past the defect. Bob. Quote Link to post Share on other sites More sharing options...
rob_x2004 Posted December 13, 2006 Share #5 Posted December 13, 2006 I am only on a laptop but I can see several lines to the left of the strong line. If it is a result of massive underexposure and rigorous processsing doesnt that tell you something though? Does it show in files of properly exposed images? Out of interests sake can you resample the whole frame image to say five hundred pixels high and put a rectangle on it to show the area of the 100% crop? Quote Link to post Share on other sites More sharing options...
carstenw Posted December 13, 2006 Share #6 Posted December 13, 2006 It's a leaky or "hot" area in the sensor marked by the cluster of black dots at the end of the white line. Charge (the image) is transferred out of the array from the bottom to the top. Image information upstream from the defect tends to be swamped by the leakage giving rise to a white line with some residual information. The image signal downstream from the defect is not corrupted and is read out normally. The leakage must be small compared to a normal signal, the defect is not visible under more usual operating conditions and some noise does appear to transfer past the defect. Bob. Robert, I thought that in the M8 the pixels were read out from the middle towards the left and right, hence the original streaking problem? Quote Link to post Share on other sites More sharing options...
blado Posted December 13, 2006 Author Share #7 Posted December 13, 2006 Advertisement (gone after registration) No, it doesn't really show on normally exposed images. I'm glad I posted the samples, tho, for feedback. it isn't really a problem, but I wonder if I should mention it when I send it in for the fix. Don't want them messing with my sensor needlessly! Quote Link to post Share on other sites More sharing options...
rob_x2004 Posted December 13, 2006 Share #8 Posted December 13, 2006 Can this failure or phenomenon be induced at some point on a perfectly good sensor, or a sensor within normal manufactured tolerances if you try hard enough to induce it? I am not having a dig, I dont know and am just asking. Also how big an area is this 100% crop. Can you overlay it onto a small resampled image of the whole frame? Quote Link to post Share on other sites More sharing options...
blado Posted December 13, 2006 Author Share #9 Posted December 13, 2006 The crop is like 1/6 the width of the original frame. And I do have to work to reveal it, so I guess it's not what you'd call a problem. Quote Link to post Share on other sites More sharing options...
gravastar Posted December 14, 2006 Share #10 Posted December 14, 2006 Robert, I thought that in the M8 the pixels were read out from the middle towards the left and right, hence the original streaking problem? The directions I gave in my original posting were with reference to the images that blado posted. Since we don't know how those relate to the sensor orientation your comment could well be correct. The fact that there are also faint vertical patterns buried in the noise would seem to indicate that blado's images have been rotated 90 degrees. Bob. Quote Link to post Share on other sites More sharing options...
ho_co Posted December 14, 2006 Share #11 Posted December 14, 2006 I'm not digitally knowledgeable and would probably never have done what you did to discover it. However, I am interested in having possible problems fixed. It may be that the M8 hardware fix will take care of this problem as well as streaking and green blobs. But then if you've already found this misbehaviour, I bet the first thing you'll do when the camera comes back from the 'fix' is to check to see if this 'non-problem' is still present, right? My personal advice would be to raise the issue with Solms when you send the camera off. Let them tell you whether it's important or not, but be sure that you alert them to it. Strictly my personal reaction, of course, but since the camera's going in, let them look at it. --HC Quote Link to post Share on other sites More sharing options...
blado Posted December 14, 2006 Author Share #12 Posted December 14, 2006 I'm sorry, I was away from my computer for a while! The images were not rotated, and the line appeared in the lower left hand corner. I will mention it when it goes in, just in case; I'm sure they'll deal with it. Quote Link to post Share on other sites More sharing options...
ho_co Posted December 14, 2006 Share #13 Posted December 14, 2006 Jon-- You may not be alone. Don't know whether this is the same or not, but the user found it with less effort than you made, and on a 'fixed' camera at that--also vertical, also always same location. http://www.leica-camera-user.com/digital-forum/11491-strange-stripe-m8.html Quote Link to post Share on other sites More sharing options...
bayerische Posted December 15, 2006 Share #14 Posted December 15, 2006 A long time ago I had the Canon eos D2000 / Kodak DCS-520 whatever you like to call it. At high ISO I hade an exactly the same effect. And it was a faulty line of pixels. Never saw it at the "lower" ISO range. Quote Link to post Share on other sites More sharing options...
blado Posted December 15, 2006 Author Share #15 Posted December 15, 2006 Hmmm. Well, I guess I'll just draw it to their collective attention when it goes in (sometime in January). Thanks, all, for having a look. Quote Link to post Share on other sites More sharing options...
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