steinzeug Posted June 8, 2011 Share #1 Posted June 8, 2011 Advertisement (gone after registration) Took this RAW image at 2500 ISO with an M8.2 against a dark surface and enhanced the image in PS. As you can clearly see the two halves of the sensor seem to be slightly uneven and there is what appears to be a faint line down the middle (maybe just the border between the two sides) Question: is this normal or the beginnings of the dreaded vertical line issue? or something else? Grateful for any comments. 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! 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/153759-is-this-the-dreaded-vertical-line-issue/?do=findComment&comment=1696255'>More sharing options...
Advertisement Posted June 8, 2011 Posted June 8, 2011 Hi steinzeug, Take a look here Is this the dreaded vertical line issue?. I'm sure you'll find what you were looking for!
mjh Posted June 8, 2011 Share #2 Posted June 8, 2011 and enhanced the image in PS. Don’t do that. It is a known cause of grief. Link to post Share on other sites More sharing options...
farnz Posted June 8, 2011 Share #3 Posted June 8, 2011 Don’t do that. It is a known cause of grief. +1 Link to post Share on other sites More sharing options...
steinzeug Posted June 9, 2011 Author Share #4 Posted June 9, 2011 yes, yes but does anyone know if this normal or the beginnings of the dreaded vertical line issue? or something else? Grateful for any comments. Link to post Share on other sites More sharing options...
farnz Posted June 9, 2011 Share #5 Posted June 9, 2011 That's what we're trying to tell you. What you're seeing is that the M8's sensor is split into 2 halves and each line of photodiodes (pixels if you like) is read out from the centre to the outside. There will naturally be a minute difference at the margin between the two halves owing to signal differentials caused by miniscule performance differences in the photodiodes, and perhaps tiny (in the order of picoseconds) synchronisation differences as a result of the ultra high speed clock pulses and capacitive effects of the components, which will show up as a slight difference in photodiode output. And the beginnings of the read-out lines naturally produce a vertical line because that's how the sensor is made up. This is what you're seeing when you turn the sensor's sensitivity up to maximum and enhancing the output and the differentials and the noise in PS. Hence it's not a good idea to do this. Imho this not the dreaded vertical line issue. Pete Link to post Share on other sites More sharing options...
garygsandhu Posted June 10, 2011 Share #6 Posted June 10, 2011 i.e. Normal. NOT the vertical line problem. Link to post Share on other sites More sharing options...
Dominum Posted June 10, 2011 Share #7 Posted June 10, 2011 Advertisement (gone after registration) Stop looking for problems and you won't find them Link to post Share on other sites More sharing options...
steinzeug Posted June 10, 2011 Author Share #8 Posted June 10, 2011 Hi, am not trying to find any problems, just intrigued to know more about how the sensor works. Thanks for the replies. Link to post Share on other sites More sharing options...
Bert N Posted June 10, 2011 Share #9 Posted June 10, 2011 The image artifact you observed is caused by imperfect charge transfer from the vertical CCD register (which is not split) to the horizontal CCD register - which is split - and the data is read out by the VOUTL and VOUTR output amplifiers as shown in the attached sensor block diagram from Kodak. The issue is typically not caused by a defect in the sensor but result from timing errors in the drive electronics, and the solution usually involves replacing the sensor control board. Hi, am not trying to find any problems, just intrigued to know more about how the sensor works. Thanks for the replies. 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! 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/153759-is-this-the-dreaded-vertical-line-issue/?do=findComment&comment=1698282'>More sharing options...
steinzeug Posted June 11, 2011 Author Share #10 Posted June 11, 2011 Many thanks, that was very interesting to read. Here is a paradox: part of Leica (analogue) cameras beauty is their longevity, the digital Leicas however are well built but their electronics will ultimately let them down. Wouldn´t it be great if Leica made D-cameras which could have their sensors exchanged with later version and developments in the future? That would be something very new on the market and at the same time strengthen Leicas profile and promise. Link to post Share on other sites More sharing options...
farnz Posted June 11, 2011 Share #11 Posted June 11, 2011 ... Here is a paradox: part of Leica (analogue) cameras beauty is their longevity, the digital Leicas however are well built but their electronics will ultimately let them down. ... Are you suggesting that the electronics in Leica film (analogue) cameras won't suffer the same fate as the electronics in a Leica digital camera? For example, try using M7 with a flat battery or a blown circuit board. I can't see the paradox to which you allude. Pete. Link to post Share on other sites More sharing options...
likealeica Posted June 11, 2011 Share #12 Posted June 11, 2011 How about an using an M4, with a dead battery, for which there isn't one, or a blown circuit board, also for which there isn't one. Mercedes and Leica, better off before their products became computers. Link to post Share on other sites More sharing options...
steinzeug Posted June 15, 2011 Author Share #13 Posted June 15, 2011 The image artifact you observed is caused by imperfect charge transfer from the vertical CCD register (which is not split) to the horizontal CCD register - which is split - and the data is read out by the VOUTL and VOUTR output amplifiers as shown in the attached sensor block diagram from Kodak. The issue is typically not caused by a defect in the sensor but result from timing errors in the drive electronics, and the solution usually involves replacing the sensor control board. Dear Bert N just for comparison I checked the sensor of another M8.2 this time the two split halves are not visable, but there were some other irregularities (see image). A wide band on the left half and what appears to be a vertical line. Would be interessting to get your opinion. Maybe i am seeing too much in these images (they are highly exaggerated in PS), but interessting to learn how the sensor operates. 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! 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/153759-is-this-the-dreaded-vertical-line-issue/?do=findComment&comment=1702676'>More sharing options...
Wowmeta Posted June 15, 2011 Share #14 Posted June 15, 2011 Look here, i have the same with M9 http://www.l-camera-forum.com/leica-forum/leica-m9-forum/178559-leica-m9-problem-stripes-banding-across.html Bye Peter Link to post Share on other sites More sharing options...
Bert N Posted June 15, 2011 Share #15 Posted June 15, 2011 The slightly darker columns you observed may be caused by poor CTE (charge transfer efficiency) in the columns. In a CCD, the signal charge in every column must be shifted from the first pixel in the column to the last pixel in the column, it is inevitable that some charge will get lost in the process, but the CTE can be as high as 6 nines (0.999999) or as low as 2 nines (0.99) per transfer, when this happens, the signal read out will be noticeably lower in intensity. Dear Bert Njust for comparison I checked the sensor of another M8.2 this time the two split halves are not visable, but there were some other irregularities (see image). A wide band on the left half and what appears to be a vertical line. Would be interessting to get your opinion. Maybe i am seeing too much in these images (they are highly exaggerated in PS), but interessting to learn how the sensor operates. Link to post Share on other sites More sharing options...
pico Posted June 15, 2011 Share #16 Posted June 15, 2011 OMG, I did some forensics on the image. Can you see the unusual figure of erred pixels? Link to post Share on other sites More sharing options...
steinzeug Posted June 15, 2011 Author Share #17 Posted June 15, 2011 The slightly darker columns you observed may be caused by poor CTE (charge transfer efficiency) in the columns. In a CCD, the signal charge in every column must be shifted from the first pixel in the column to the last pixel in the column, it is inevitable that some charge will get lost in the process, but the CTE can be as high as 6 nines (0.999999) or as low as 2 nines (0.99) per transfer, when this happens, the signal read out will be noticeably lower in intensity. Is that bad or good? Link to post Share on other sites More sharing options...
Bert N Posted June 15, 2011 Share #18 Posted June 15, 2011 While 2 nines CTE is very bad, your sensor seems to have developed a remarkable grouping of anomalous pixels Is that bad or good? Link to post Share on other sites More sharing options...
steinzeug Posted June 15, 2011 Author Share #19 Posted June 15, 2011 While 2 nines CTE is very bad, your sensor seems to have developed a remarkable grouping of anomalous pixels Thanks, but does this mean we will need to change the sensor or is it ok to use? Link to post Share on other sites More sharing options...
Bert N Posted June 15, 2011 Share #20 Posted June 15, 2011 If you're referring to the CTE issue, note that I'm not suggesting that the dark columns present in the posted image are caused by a serious CTE problem in the sensor. When an image is captured in the dark, the signal is very low, and it doesn't take much to form image artifacts, but if you shot under normal lighting conditions, and you see similar dark columns in the image, then the sensor may be defective. Thanks, but does this mean we will need to change the sensor or is it ok to use? Link to post Share on other sites More sharing options...
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