I have received an exported jpg and dng file which derived from the same original raw (.cr2) file. I need to make sure that the dng is in fact an exact replica of the raw (.cr2 file). Given the information the exiftool gave me, is there any data that would object this not being a replica of the raw file?
The jpeg results of the exiftool show the file history, why doesn't the dng file show me that? Does that tell me that the dng is in fact the original because it was converted exactly from the raw file to dng?
My goal here is to make sure I have an exact replica of the raw file at hand, whether it's the dng or jpeg. Is that possible to tell given the results for from the exiftool? ***Given the fact that lightroom can warp, clone....etc, I want to make sure that the .dng file did not have any of these effects added to it.
*I've attached the results from both the jpg and dng file but excluded the directory and names for privacy reasons. With that said, is it normal to also have a different artist name and owner name?
If you worry about the original raw file: it's actually embedded in the dng you got!
Isn't embedding the raw in a dng just an option? Though it would be something to double check on.
Quote from: StarGeek on October 04, 2017, 04:10:18 AM
Isn't embedding the raw in a dng just an option? Though it would be something to double check on.
It
is an option, but the dng file in this case
does have it embedded :)
When the raw is not embedded, I would never trust the Adobe DNG converter to preserve all information from the original raw file -- I know for a fact that there is metadata that is lost, and Adobe knows this too, but they don't care enough to fix it. Also, the metadata is converted to a proprietary Adobe format, which is pretty-well useless for any software except perhaps Adobe software (I know of no other software but ExifTool that can read this format).
- Phil
Quote from: Hayo Baan on October 04, 2017, 06:40:36 AM
Quote from: StarGeek on October 04, 2017, 04:10:18 AM
Isn't embedding the raw in a dng just an option? Though it would be something to double check on.
It is an option, but the dng file in this case does have it embedded :)
Thank you for your reply......but what do you see in the script returned by the ExifTool that signifies that the raw file was embedded?
Quote from: AL10 on October 04, 2017, 02:07:09 PM.but what do you see in the script returned by the ExifTool that signifies that the raw file was embedded?
Original Raw Image : (Binary data 21020688 bytes, use -b option to extract)
Could that line have been added by the user? I know that metadata is not write protected so in this instance could the photographer have added that line in?
It's not a line. It's 21,020,688 bytes (21 megabytes) of binary data. Yes, it's technically possible that they added a 21 megabyte junk file to the DNG, but it's easy enough to extract it and check it out.
exiftool -b -OriginalRawImage >_GIA0026.CR2 File.dng
I used _GIA0026.CR2 as that was the Original Raw File Name, but you can use whatever you want. Make sure you use CMD if you're on Windows, as Powershell will corrupt the redirection.
Quote from: StarGeek on October 04, 2017, 04:13:20 PM
It's not a line. It's 21,020,688 bytes (21 megabytes) of binary data. Yes, it's technically possible that they added a 21 megabyte junk file to the DNG, but it's easy enough to extract it and check it out.
exiftool -b -OriginalRawImage >_GIA0026.CR2 File.dng
I used _GIA0026.CR2 as that was the Original Raw File Name, but you can use whatever you want. Make sure you use CMD if you're on Windows, as Powershell will corrupt the redirection.
You'll have to forgive me as I'm completely new to using the ExifTool but I do have an extensive background in photography/post production. Thus far all I'm using it for is to drag photos to to extract data I need.
Can you clarify and explain how you extracted that information and which lead you to know it was a valid .dng file?
I don't know it's a valid DNG or if the embedded CR2 is valid or not. But the fact that exiftool reports that OriginalRawImage contains "Binary data 21020688 bytes" is not something that can be faked. The file reports that there is a chunk of data 21,020,688 bytes long in the file. If this wasn't the case, if the number of bytes was more or less, then when exiftool jumps to try and read the next bit of data after that, it would read some random bit of data, not the header for the next chunk of data. It would then return an error reporting a problem with the file format.
So there is 21 megs of binary data in there. That part can't be faked. Is it a valid CR2? Or the same CR2 that the DNG was created from? The only way to tell would be to extract it and compare it to DNG file. Technically, it could be just a junk file of some sort or a completely different CR2 file. But then it becomes a technical problem of inserting such a file into the DNG. I haven't used Adobe DNG Converter but I sorta doubt that it has the ability to embed a selected image into a completely different DNG file. Exiftool doesn't have that ability. And a quick google search returns no relevant results. So they're going to have to write their own program to do so.
And when it comes down to it, what would be the point? You could easily extract the embedded raw with Adobe DNG Converter or with exiftool as mentioned above. It could then be compared to the DNG for any differences. So what would be the point of doing so?
Basically, you can't fake the fact that there's 21 megs of binary data in that file. The file would be invalid otherwise. Whether there's a valid CR2 file embedded or not is something only you can figure out.
Quote from: AL10 on October 04, 2017, 01:58:40 AMWith that said, is it normal to also have a different artist name and owner name?
Almost forgot this part of the question. Some cameras have an settings option to embed the owners name in the image. Copyright is often added in processing of the file. I think the logic here is that the owner of the camera may not be the copyright holder. That said, the
OwnerName tag is usually ignored by most software.
Quote from: AL10 on October 06, 2017, 03:18:43 PM
Quote from: StarGeek on October 04, 2017, 04:13:20 PM
It's not a line. It's 21,020,688 bytes (21 megabytes) of binary data. Yes, it's technically possible that they added a 21 megabyte junk file to the DNG, but it's easy enough to extract it and check it out.
exiftool -b -OriginalRawImage >_GIA0026.CR2 File.dng
I used _GIA0026.CR2 as that was the Original Raw File Name, but you can use whatever you want. Make sure you use CMD if you're on Windows, as Powershell will corrupt the redirection.
You'll have to forgive me as I'm completely new to using the ExifTool but I do have an extensive background in photography/post production. Thus far all I'm using it for is to drag photos to to extract data I need.
Can you clarify and explain how you extracted that information and which lead you to know it was a valid .dng file?
I totally understand everything you said regarding the 21mb but i wanted clarity on what you mean by "its easy enough to extract it and check it out". Then you proceeded with this"exiftool -b -OriginalRawImage >_GIA0026.CR2 File.dng". What does that tell me? I just wanted a better understanding of what you did and what your trying to do with that line.
Oh, my apologies then for misunderstanding.
That command will extract the original CR2 file from the DNG file. You could then load both into Lightroom or a similar program and visually compare them. Adobe DNG Converter could also be used to extract the CR2 file.