Adulterated Images and Missing Images.

[joebranko]

I have experienced two strange phenomena recently on which I would like some input to help me determine what is happening with my equipment/software. These problems are spread over 3 photoshoots.

In the first instance when I exported this image after processing I got three images, two normal images separated by an image which looks like a multi-colour smudge, as shown below.
Image 5929-2


Here is the preceding image: Img 5929



Here is the image which followed: Img 5929-3



These images are all from the same exposure img 5929: When you save second or third copy of an exposure Lightroom asks if it should overwrite or use a unique number. I don't recall doing this but I must have elected " Unique Number".

This anomaly happened several times when I processed the shots from this photoshoot. I think 12 times. If it is important I can look back and find this.
I assumed something was wrong with the SD card so I formatted it in my camera. It is a 16 GB ScanDisk Ultra 30MB/s.

Later I went on another photo shoot. Everything was OK in this shoot.

A few days later I went on another shoot and everything seemed OK. I was able to look at every exposure and adjust as needed. However when I returned from the shoot, and looked at the exposures on my computer, I could find only one exposure ( the very first) from that shoot on the SD card. When I put the SD card back in the camera all from this last shoot, except the one mentioned above, were missing. Also the one surviving shot from this last shoot was not in sequence that I took it. It appeared in the third 'slot' of the previous shoot. I think I may have deleted a shot from the aforementioned shoot.

So I don't know if I have a problem with the SD card, the camera or the processing software, or if these problems are independent of each other or what? Can a problem in any one of these cause damage to another?
Appreciate your input to resolve this.

My camera is a Canon t2i
PP software is Lightroom 6
SD card is Scandisk 16GB 30MB/s

[Dave Humphries]

Joe,

You need to give us more to go on; e.g. what were you exporting from?

If we have to guess you equipment/software, this could be a very long and rambling thread

TIA, Dave

[Manfred M]

Joe - I tend to agree with Dave, you haven't given us much to work with.

That being said, I have seen this type of result before when the data gets corrupted when the output file is written. As JPEG files rely on data compression, a write error can throw off the whole decoding operation. As for the cause of the corruption, that is anyone's guess. Try saving it again to see if you get the same result.

[joebranko]

Joe,

You need to give us more to go on; e.g. what were you exporting from?

If we have to guess you equipment/software, this could be a very long and rambling thread

TIA, Dave

Sorry Dave. I had a bit of a health issue in the middle of my post and had to interrupt half way through. I am better now and can continue posting.

I was doing my PP in Lightroom and exporting to my hard drive.
I will try to edit my original and continue there.

[joebranko]

Joe - I tend to agree with Dave, you haven't given us much to work with.

That being said, I have seen this type of result before when the data gets corrupted when the output file is written. As JPEG files rely on data compression, a write error can throw off the whole decoding operation. As for the cause of the corruption, that is anyone's guess. Try saving it again to see if you get the same result.

Thanks Manfred. This anomaly has happened in that shoot. I have not counted but I would say 12 times.
Please see my edit to my original thread for further details.

[DanK]

Joe,

I think this is the key:

However when I returned from the shoot, and looked at the exposures on my computer, I could find only one exposure ( the very first) from that shoot on the SD card. When I put the SD card back in the camera all from this last shoot, except the one mentioned above, were missing.

This seems to make clear that the source of the problem isn't software. It seems most likely that the problem is either a bad SD card or a problem with the camera. A faster version of your SD card (a SanDisk Extreme 16 GB 40 MBS/s write speed) costs only $11. I'd simply buy one and try it out. If the problem doesn't recur, throw out the old SD card, and all will be well. If it does recur, that would seem to suggest that the camera is having problems writing to the card.

Dan

[Manfred M]

+1 to Dan's comment. If you have a suspect card, throw it out and replace it with a new one. I have had some data corruption problems with some lower end cards, but now exclusively shoot either Lexar or Sandisk. They cost a bit more, but I have never had a data corruption issue with them.

[rpcrowe]

The example posted above is what the test images looked like when I was using my second Kingston card that failed initially. It has been Lexar or SanDisk exclusively for me since...

[Merlin52]

Bad SD card. Throw it out and get a new one for New Year

[joebranko]

Installed new SD card. I don't get any weird pics so that problem appeared solved. However I still am getting missing pics. I took my camera in to the camera shop for analysis/troubleshooting. Won't hear for about 1 week.😞

[joebranko]

In a related question: The image which appears on the LCD display immediately after making an exposure; is the data for that exposure stored on the SD card or some memory card internal in the camera?

[xpatUSA]

In a related question: The image which appears on the LCD display immediately after making an exposure; is the data for that exposure stored on the SD card or some memory card internal in the camera?

Joe, do you mean the image data, the meta-data (e.g. EXIF/XMP/Maker Notes), or both?

[joebranko]

Hi Ted. I am referring to the image data.

[xpatUSA]

Hi Ted. I am referring to the image data.

Thanks Joe. For some cameras that JPEG image data is embedded in the raw file and can be recovered by some means, don't know how for your camera.

The JPEG quality may not be the best possible, 4:2:0 or 4:2:2 are typical, IMHO, in other words "FINE" doesn't automatically get you 4:4:4 in spite of what one might think.

Pardon me for assuming that you shoot raw . .

[joebranko]

Yes you are correct. I do shoot raw . I am trying to understand how I could loose images from a brand new SD card after seeing them on the LCD monitor after making an exposure. I thought that if I saw them on the monitor and the data was on the SD card , it must still be there and I should be able to recover it.
My camera is now at the repair shop . I am hoping it's not too serious a problem.

[xpatUSA]

Yes you are correct. I do shoot raw . I am trying to understand how I could loose images from a brand new SD card after seeing them on the LCD monitor after making an exposure. I thought that if I saw them on the monitor and the data was on the SD card, it must still be there and I should be able to recover it.

I understand your frustration. Corrupted raw images like yours are quite common in the world of S*g*a, it doesn't take much. In that world, there are utilities galore to try and rescue the raw and, if that doesn't work, to extract the embedded JPEG and run with that. Even the proprietary raw converter can extract JPEGs.

Pardon the minority camera mention . . .

My camera is now at the repair shop . I am hoping it's not too serious a problem.

Good luck with the shop.

[Tronhard]

I actually READ the manual for one of my cameras and discovered that if I shoot ONLY in RAW that the image displayed is a "virtual" JPG and is not stored as a separate entity, but is essentially only for viewing, not editing purposes. For that reason I have chosen to shoot in RAW and JPG and never had a problem.

[xpatUSA]

I actually READ the manual . . .

Call yourself a man? . .

[Tronhard]

Call yourself a man? . .

It was my feminine side coming out, I admit...

[joebranko]

Thanks Ted and Trev. I only shoot in R AW so the virtual image hypothesis explains what I am seeing. Thanks for this input.