Gary Clennan Posted September 3, 2014 Share #1 Posted September 3, 2014 Advertisement (gone after registration) I'm hoping one of you may be able to help me out with this. Every now and again I have a DNG file (M240) with comes out like the one below. It happens very rarely - maybe one pic in every 200 or so. I am using Lightroom but have also tried to open them in other software with the same result. I always shoot DNGs and process through LR. My guess is that perhaps this is what happens (at times) when I turn off the camera while it is still writing to the card? I sent a file to Leica and they only advised me to send in the camera if it continues. Any guess as to what might be causing this? L1009034 by garyclennan, on Flickr Link to post Share on other sites More sharing options...
Advertisement Posted September 3, 2014 Posted September 3, 2014 Hi Gary Clennan, Take a look here Strange Image Output. I'm sure you'll find what you were looking for!
jip Posted September 3, 2014 Share #2 Posted September 3, 2014 I think it has to do with your SD card, I've seen this once on my M240 and after I have ditched the card and bought a new one I've never had the problem anymore... Link to post Share on other sites More sharing options...
John Black Posted September 3, 2014 Share #3 Posted September 3, 2014 I think that's an SD card issue as well. Have you tried SD Formatter? https://www.sdcard.org/downloads/formatter_4/ I do the full format option at least once a month per SDHC card. It also helps to keep the start-up times short(er) too, which tend to erode over time as the card gets more and more use - essentially fragmenting the storage space. Link to post Share on other sites More sharing options...
Gary Clennan Posted September 3, 2014 Author Share #4 Posted September 3, 2014 Yes, all of my cards are run through sdformatter. I suppose I should try to remember if a certain card is having these issues and then try another brand. Link to post Share on other sites More sharing options...
tobey bilek Posted September 3, 2014 Share #5 Posted September 3, 2014 SD formater might be nice, but format the card in the camera in which it will be used. I buy 2 card when I buy a camera. They stay with the camera until it dies. And buy from a trusted source like B&H. Their 2 pack deals are cost effective. Link to post Share on other sites More sharing options...
CheshireCat Posted September 4, 2014 Share #6 Posted September 4, 2014 Are the artifacts present when reviewing the image on the back LCD just after you take the photo ? Link to post Share on other sites More sharing options...
menos I M6 Posted September 4, 2014 Share #7 Posted September 4, 2014 Advertisement (gone after registration) I use Mac computers and made diglloydTools an essential part of my photographic workflow. Highly recommended to regularly use on all digital media in use (and backups as well). Link to post Share on other sites More sharing options...
Gary Clennan Posted September 4, 2014 Author Share #8 Posted September 4, 2014 Are the artifacts present when reviewing the image on the back LCD just after you take the photo ? I am pretty sure that I have never seen this appear on the preview image on the LCD. At least, I have never noticed it.... Link to post Share on other sites More sharing options...
Telfs Posted September 4, 2014 Share #9 Posted September 4, 2014 I am pretty sure that I have never seen this appear on the preview image on the LCD. At least, I have never noticed it.... The "review" image visible after you take the shot is, I suspect, created from the camera's buffer and so is unlikely to display these characteristics. If, however, you "play" an image, it will be retrieved from the card and should do so if the card is indeed the problem. Link to post Share on other sites More sharing options...
CheshireCat Posted September 4, 2014 Share #10 Posted September 4, 2014 I am pretty sure that I have never seen this appear on the preview image on the LCD. At least, I have never noticed it.... If so, this means that your camera hardware is ok up to the RAM buffer where the last captured image is stored. Now if the artifacts show up when you power-cycle the M and then review your shots in the camera, it means that the SD card is faulty and must be replaced. Otherwise, the problem is your SD card reader. Link to post Share on other sites More sharing options...
colonel Posted September 4, 2014 Share #11 Posted September 4, 2014 I have seen that before on a Canon 5Dii I am 99% sure that SD card is duff Don't waste your time mucking around and I wouldn't bother formatting it. I would use another SD card. Take the card back if under warranty, most of these things have life time warranties these days Link to post Share on other sites More sharing options...
Gary Clennan Posted September 5, 2014 Author Share #12 Posted September 5, 2014 Thanks to everyone! I don't recall (although I could be wrong) ever seeing this issue when playing back images after the shot was taken. I really don't chimp much though so I could be wrong. I am planning on paying close attention to which card is causing the issue and then try to work it from there. Thanks again for the responses! Link to post Share on other sites More sharing options...
Gary Clennan Posted September 6, 2014 Author Share #13 Posted September 6, 2014 Arghh!! I was out today shooting and encountered the very same problem. I was careful to keep an eye on things and this is what I observed: Image preview was perfectly fine Playback of the image was perfectly fine Image in LR is messed up Another important note... I imported the images into LR and then removed the SD card once complete. Not exactly sure what to call it but once all images are in LR, it starts to "build" the images or something similar. You can see it go image by image until complete. All the images looked perfectly fine until LR "processed" it. Basically once imported, all images looked great in LR but then after it got to one of the images, it made it have that strange effect above. I am also pretty sure that the other issues were with a different SD card than the one I used today. I'm not sure where to start.... Advice? Link to post Share on other sites More sharing options...
CheshireCat Posted September 6, 2014 Share #14 Posted September 6, 2014 Another important note... I imported the images into LR and then removed the SD card once complete. Not exactly sure what to call it but once all images are in LR, it starts to "build" the images or something similar. You can see it go image by image until complete. All the images looked perfectly fine until LR "processed" it. Basically once imported, all images looked great in LR but then after it got to one of the images, it made it have that strange effect above. I am also pretty sure that the other issues were with a different SD card than the one I used today. I'm not sure where to start.... Advice? DNG images embed a little JPG preview that is computed by the camera. This is what Lr shows until it compute its own preview on the actual raw data. I believe the JPG preview is also what the camera shows when you preview the picture in camera, unless you zoom in. If zooming in the picture while reviewing it in-camera reveals the same artifacts, then the issue is probably the SD card. Otherwise the corruption happens during transfer from the camera or card-reader to the computer. How do you import images to your computer ? Link to post Share on other sites More sharing options...
Gary Clennan Posted September 6, 2014 Author Share #15 Posted September 6, 2014 DNG images embed a little JPG preview that is computed by the camera. This is what Lr shows until it compute its own preview on the actual raw data. I believe the JPG preview is also what the camera shows when you preview the picture in camera, unless you zoom in. If zooming in the picture while reviewing it in-camera reveals the same artifacts, then the issue is probably the SD card. Otherwise the corruption happens during transfer from the camera or card-reader to the computer. How do you import images to your computer ? Thanks! I plug my card direct into the side of my iMac. Link to post Share on other sites More sharing options...
menos I M6 Posted September 6, 2014 Share #16 Posted September 6, 2014 This sounds indeed like image file corruption. Be aware that DNG files are basically a container filled with RAW data, which can only interpreted by a raw file converter such as Lightroom. To be able to see an image preview on the screen of your digital camera, as well as a preview in most file browsers and quick previews in image managing software a little "helper" preview JPG is embedded into the DNG container (very low res). What you see on the back of your digital camera is this very little JPG file. What you see as an initial preview during import in Lightroom is just that very tiny JPG preview from the DNG container. Lightroom then continuous to calculate it's own higher res library preview file directly from the RAW data in the DNG container. This is where you will first see the issue with corrupted files. The RAW data of the DNG file is damaged (in most cases irretrievable). The cause lies either in a corrupted SD card (most of the times) or in a fault during writing of the raw file to the SD card in camera (for example when you shoot a burst of images with an almost empty battery in an old generation digital Leica M - the sudden surge of needed energy can be too much for the camera's operation at that given moment, sometimes resulting in corrupting image data during writing to SD card). In an earlier post I suggested a suite of data checking and stress testing tools. I run regularly all my media through these tools (and yes, corrupted SD cards are reality but can be often repaired). A regular formatting of an SD card does not necessarily find and certainly not always "repair" corruption. A proper fill write and stresstest combined with reconditioning though will find corrupted sectors and often will be able to repair (exclude) them, making the given card good for use again. Btw - exactly the same issues will for certain corrupt digital files stored on media. If data integrity is important to you, a proper workflow of regular checks (hash checks for file integrity) is mandatory. Above named tools (I am not affiliated, just a satisfied user) can be one part of such a workflow (proper backups and regular checks should be the other). Link to post Share on other sites More sharing options...
Gary Clennan Posted September 6, 2014 Author Share #17 Posted September 6, 2014 Excuse my ignorance but I am not so tech-savy... Are you suggesting that I use this software (or similar) to test my SD card and repair if needed? Is there anything further I can do to narrow down the problem to just the card? I would rather not shell out any money unless I am confident it will resolve the issue. FYI - I am using a Samsung 64GB pro (came with subscription to LFI), and mainly Lexar Professional 32GB cards. Really apprecite the help. Link to post Share on other sites More sharing options...
pop Posted September 6, 2014 Share #18 Posted September 6, 2014 There is ample reason to assume that the card is at fault. Formatting the card with the program mentioned in the third post in this thread might fix it. But then, it might not. If you use the program, it's of the utmost importance that you use the option to overwrite the data. This may take quite some time. Link to post Share on other sites More sharing options...
Gary Clennan Posted September 6, 2014 Author Share #19 Posted September 6, 2014 OK - did some more testing this morning, here is what I managed to determine: 1) I opened that native DNG file with CS5 with no issues. The moment it opened the image, it showed the problem but then the image quickly appeared as it should. I made some test adjustments in CS5, saved it (as a TIF) with no issues. 2) I downloaded the problem DNG files from the SD card to my computer using both the mac SD port and then again with an external card reader. 3) I imported (separately) both of these DNG files into LR and then opened them up. There were no issues at all. Could it perhaps be the LR software causing issues upon import? It seems that the camera is writing the data properly, the card is recording the data properly, and the transfer from the card to the computer is happening as it should. Where to go from here? Link to post Share on other sites More sharing options...
CheshireCat Posted September 6, 2014 Share #20 Posted September 6, 2014 1) I opened that native DNG file with CS5 with no issues. The moment it opened the image, it showed the problem but then the image quickly appeared as it should. I made some test adjustments in CS5, saved it (as a TIF) with no issues. 2) I downloaded the problem DNG files from the SD card to my computer using both the mac SD port and then again with an external card reader. 3) I imported (separately) both of these DNG files into LR and then opened them up. There were no issues at all. 1) This may be because Lightroom had updated the little JPG preview with the bad image. Then CS5 recomputed it from raw data. It might be that CS5 is better at handling bit errors in the raw data (which only makes sense if you have enabled DNG compression in your M, let us know if this is the case). 2) Ok. 3) This is weird. If the files can be read fine from SD sometimes, then it may be that bit errors only happen under some conditions (such as high tempreature). Keep using your external card reader, and let us know if you still see this issue. Link to post Share on other sites More sharing options...
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