jmahto Posted January 23, 2014 Share #1 Posted January 23, 2014 Advertisement (gone after registration) While pixel peeping my dune picture I noticed an interesting pattern in the ripples (see vertical lines in 1:1 crop). First I thought it as a real pattern in the sand but when I checked the other picture, the pattern was not there in the same part of the dune. In some other picture the vertical line were in different areas. After examining more shots, I have a suspicion that these vertical lines are in the same area of the sensor (note that it is difficult to be sure since I have only a handful pictures with similar fine ripples in same part of the sensor for the vertical artifacts to be visible. The vertical line is not visible when the ripples are wider or have different texture - which is the case in most of the picture). In any case, this doesn't bother me. The pattern are so fine that they are visible only on 1:1 and so far I have seen them only on very specific kind of picture (very fine ripples). Just wanted to share. If you have seen similar artifacts in your M9 then I won't feel lonely though. 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/220714-interesting-pattern-from-m9-sensor/?do=findComment&comment=2516215'>More sharing options...
Advertisement Posted January 23, 2014 Posted January 23, 2014 Hi jmahto, Take a look here Interesting pattern from M9 sensor. I'm sure you'll find what you were looking for!
Ecar Posted January 23, 2014 Share #2 Posted January 23, 2014 Looks like moiré to me. Link to post Share on other sites More sharing options...
jmahto Posted January 23, 2014 Author Share #3 Posted January 23, 2014 I thought so too but not 100% sure. Link to post Share on other sites More sharing options...
gvaliquette Posted January 23, 2014 Share #4 Posted January 23, 2014 Moire. If you look closely, the pattern does not extent to the full height of the image, even in the 1:1 crop! Guy Link to post Share on other sites More sharing options...
Leicakillen Posted January 23, 2014 Share #5 Posted January 23, 2014 I thought so too but not 100% sure. Have you tried to correct the pattern with the Moire-tool in Lightroom? If it is Moire - it would be possible to correct in PP. /Anders Link to post Share on other sites More sharing options...
mjh Posted January 23, 2014 Share #6 Posted January 23, 2014 Could be moiré (or, more precisely, a demosaicing artefact), but it does look odd. It would be worth checking whether it looks the same in a different raw converter. Link to post Share on other sites More sharing options...
jmahto Posted January 23, 2014 Author Share #7 Posted January 23, 2014 Advertisement (gone after registration) Have you tried to correct the pattern with the Moire-tool in Lightroom? If it is Moire - it would be possible to correct in PP. /Anders The moire correction in LR (I use LR5) only corrects the false colors patterns. It doesn't move the actual pixels (my observation). I tried it here and it didn't do anything. I don't have access to any other RAW converter. I can provide the DNG if someone wants to play around and have fun Link to post Share on other sites More sharing options...
mjh Posted January 23, 2014 Share #8 Posted January 23, 2014 I can provide the DNG if someone wants to play around and have fun Please do. Link to post Share on other sites More sharing options...
jmahto Posted January 23, 2014 Author Share #9 Posted January 23, 2014 Moire. If you look closely, the pattern does not extent to the full height of the image, even in the 1:1 crop! Guy I was first excited to have discovered a weird phenomenon on the sand ripple pattern. My excitement was short lived after thinking through. BTW, my friend was shooting with 5DIII the same dunes and he has no such patterns but less detail on the ripples. I am not sure what is better... less detail or false detail. But as I said, it doesn't bother me since it was so rare and I corrected it in Photoshop by moving pixels for the ones I intend to print big. It was fun sharing though. Link to post Share on other sites More sharing options...
jmahto Posted January 23, 2014 Author Share #10 Posted January 23, 2014 Please do. I will do it tonight. If I upload to Google drive with public access, can it be picked up? Link to post Share on other sites More sharing options...
Mr_Jones Posted January 23, 2014 Share #11 Posted January 23, 2014 Dropbox is easier. You can place it in the public folder and share the link. Link to post Share on other sites More sharing options...
jmahto Posted January 24, 2014 Author Share #12 Posted January 24, 2014 Here is the dropbox link for the DNG. Let me know if you can't access it. I will be very much interested in knowing whether other RAW converters (I use LR5) can see this strange artifact. Thanks in advance. https://www.dropbox.com/s/q0ox9rcgtm4t7nb/20131221DeathValleyPhotoTrip-1070975.DNG Link to post Share on other sites More sharing options...
250swb Posted January 24, 2014 Share #13 Posted January 24, 2014 Opening it in Photoshop (same ACR as Lightroom) and I see four lines of interference all on the same sand dune, but nowhere else. Opening in RAWTherapee and the same lines are still in the picture, so it looks like it comes from the camera. FWIW Photoshop 'Content Aware Fill ' removes them almost perfectly. Steve Link to post Share on other sites More sharing options...
wattsy Posted January 24, 2014 Share #14 Posted January 24, 2014 It's a very nice photograph. I wonder if the line might be created by a pixel column defect repair (where the whole line is remapped, not just the recalcitrant pixel) though I guess it might just be a weird moire effect (there are plenty of other more normal looking moire artefacts). Link to post Share on other sites More sharing options...
jaapv Posted January 24, 2014 Share #15 Posted January 24, 2014 A pixel defect line would not have a pattern in it. Link to post Share on other sites More sharing options...
wattsy Posted January 24, 2014 Share #16 Posted January 24, 2014 A pixel defect line would not have a pattern in it. I referred to a pixel defect line that had been remapped, not the original defective line. Link to post Share on other sites More sharing options...
250swb Posted January 24, 2014 Share #17 Posted January 24, 2014 I suspect it is a moiré artefact. The lines are localised on the dune with the high contrast shadows and the artefact fades out as the shadows change. And yes, it is a very nice photograph, and easily fixed. Steve Link to post Share on other sites More sharing options...
hermanp Posted January 24, 2014 Share #18 Posted January 24, 2014 I processed this image in DxO. The lines (I see two of them) seem a moiré effect to me. I attach a screenshot of a portion of one of the lines at 200% where the effect is easily seen. 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/220714-interesting-pattern-from-m9-sensor/?do=findComment&comment=2517156'>More sharing options...
em9 Posted January 24, 2014 Share #19 Posted January 24, 2014 It's a very nice photograph. I wonder if the line might be created by a pixel column defect repair (where the whole line is remapped, not just the recalcitrant pixel) though I guess it might just be a weird moire effect (there are plenty of other more normal looking moire artefacts). I tend to agree with the remapped column idea. I have one of those lines on my sensor. You can reproduce them by shooting e.g. a laptop screen (turned on, focus so you can see the individual pixels at 100%, slant the screen a bit back or tilt the camera a bit, because with exactly straight lines they're harder to spot). The two (or more) columns should show up between the moire, always at the same spot. Link to post Share on other sites More sharing options...
mjh Posted January 24, 2014 Share #20 Posted January 24, 2014 Opening it in Photoshop (same ACR as Lightroom) and I see four lines of interference all on the same sand dune, but nowhere else. Opening in RAWTherapee and the same lines are still in the picture, so it looks like it comes from the camera. Iridient Developer does show these artefacts as well which suggests a hardware issue – probably a remapped column as has been mentioned before. Link to post Share on other sites More sharing options...
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