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I'm in photo-backup-deduplication hell. Thousands of folders organised in a different way, backups of backups of backups. There's no easy way to know what's latest/more important.

I'm using dupeGuru and it found many duplicates with different metadata. This answer is very good, it says that new metadata were probably added by visualisation software like Picasa. So it doesn't really matter which version I pick, since these can be re-generated*.

However, by the looks of their names and description, it seems that a lot of these metadata could only be generated by the camera; they seem to be hardware-related:

Exif:

Exposure Mode: Auto exposure
Digital Zoom Ratio: 1
Custom Rendered: Normal process Scene Capture Type: Standard
White Balance: Auto white balance

Also flipped information on Focal Plane X Resolution and on Pixel X Dimension too (X value on Y and Y on X).

TIFF:

Orientation: 6(Rotated 90o ACW)

Maybe they were added as default values?

How can I make sure I'm not losing anything important?

Are these metadata really newer and generated by software or can I somehow irretrievably erase data?

I've never used any photo editing tools on these photos. They are all JPG.

The only differences are in metadata, resolution and "content" are the same. I also didn't fix rotation in any of these pictures.

*- This is important to me because - in the middle of the huge mess that are my photo libraries - I elected one folder to be the organised/official, which never gets anything deleted, and everything else is compared against it. So it happens that sometimes the official one is the one that has photos with less metadata.

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  • \$\begingroup\$ INFO: Your post is tagged [exiftool]. Is this something you added or was it added automatically by StackExchange? I ask because if it is something you're using, I can refine my answer to be closer to the output that you would see with exiftool. \$\endgroup\$
    – StarGeek
    Commented Mar 24, 2021 at 6:01
  • \$\begingroup\$ What does "Also inverted information" mean? \$\endgroup\$
    – Saaru Lindestøkke
    Commented Mar 24, 2021 at 11:53
  • \$\begingroup\$ Remember to check the file sizes too. If copy A is twice the size of copy B, perhaps B is more compressed (and therefore not as good), or perhaps A was simply rotated 90° and due to the way jpegs work it ended up much larger. \$\endgroup\$
    – Ray Butterworth
    Commented Mar 24, 2021 at 13:02
  • \$\begingroup\$ You definitely don't want to remove the "Orientation" meta tag. Without it the photo will by default be displayed tipped on its side. \$\endgroup\$
    – Ray Butterworth
    Commented Mar 24, 2021 at 13:03
  • \$\begingroup\$ @StarGeek I tried using exiftool but ended up getting all the info I needed from macOS's Preview inspector. \$\endgroup\$
    – Roberto
    Commented Mar 25, 2021 at 2:29

3 Answers 3

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If you have never used photo editing software with the images the images are all camera generated jpegs(?) and there should not be any major difference in the metadata.

In that case the images with the minimum metadata should be the originals and there is nothing to really be concerned about.

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  • \$\begingroup\$ Hi. Can you please elaborate a bit more on why the one with the smallest metadata is the original? Your answer seems to be the opposite of StarGeek’s because he said EXIF is mostly generated by camera. Thanks \$\endgroup\$
    – Roberto
    Commented Mar 26, 2021 at 14:51
  • \$\begingroup\$ Because any exif generated by a secondary program would be in addition to the camera generated exif; which is the relevant data of concern. If you had possibly edited the image and output it with the exif stripped that might not be the case... but then there wouldn't be any (much) exif at all. Only an editing program outputting a new file can/will strip exif. \$\endgroup\$
    – Steven Kersting
    Commented Mar 26, 2021 at 15:19
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There are multiple standards when it comes to photo metadata. EXIF is one type, IPTC IIM/Legacy is another, and then XMP (which includes IPTC Core/Ext).

Most of the data in the EXIF block is data from the camera that created the image, though there are a few others that do get added by other software, such as Artist and Copyright. Anything that is in the IPTC IIM block is almost certainly data added at a later point, as I don't believe there is a camera that writes this data. Amost any XMP data is also data that was added later, though some more modern cameras do save the regions recognized as faces in XMP.

The examples you list above are almost certainly all part of the EXIF block and data from the camera. Whether they are important to you is your decision. If you think there is some point where you will get really serious about knowing how your images were shot, then they should be saved. But unless they are RAW images of some type (CR2, NEF, ARW, DNG, etc), then the existence or removal of that data won't affect the image. Never remove EXIF data from a RAW image as that will probably permanently corrupt the image.

Additional blocks you might find would be the MakerNotes, which is basically more advanced EXIF data, specific to each individual camera type. Also there is the possibility of an ICC Profile, though that usually comes from editing an image. The ICC profile should not be removed as it will affect the colors of an image.

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  • \$\begingroup\$ As a matter of fact most contemporary cameras can add Artist and Copyright tags on the moment you make the photo. \$\endgroup\$
    – Romeo Ninov
    Commented Mar 24, 2021 at 6:22
  • \$\begingroup\$ Would removing the EXIF block on a JPEG also remove the captured date? I can imagine that is interesting information to keep, regardless of RAW/JPEG. \$\endgroup\$
    – Saaru Lindestøkke
    Commented Mar 24, 2021 at 11:54
  • \$\begingroup\$ @Saaru Lindestøkke Yes, the timestamp for when the picture was taken is held in the EXIF block. \$\endgroup\$
    – StarGeek
    Commented Mar 24, 2021 at 14:26
  • \$\begingroup\$ Canon's 1-Series cameras and some recent 5-Series cameras can embed IPTC info at the time the image is taken. I don't know of any of that info uses the IPTC IIM block or not. \$\endgroup\$
    – Michael C
    Commented Mar 24, 2021 at 22:15
  • \$\begingroup\$ @StarGeek I only have JPGs. You mentioned the tags I posted were probably generated by the camera (since they are EXIF). In this case, how do you think the metadata got removed? \$\endgroup\$
    – Roberto
    Commented Mar 25, 2021 at 2:44
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The way to avoid losing anything important is to keep everything.

Disk space is inexpensive.

Your goal is probably to find pictures more easily.

Multiple copies makes finding a particular picture easier.

The right approach is search. It is not a grand scheme of organized folders. Search is why you use Google.

Pick a photo manager and spend your time tagging. Nothing will be lost. All the time you spend tagging will make pictures easier to find.

Start tagging your new photos. Then they will be easier to find too.

It's ok to have pictures in a dozen different file organization schemes. Nobody will judge you.

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    \$\begingroup\$ While this answer seems liberating, it can also create the situation that you never know if you have a certain photo in the long term. E.g. drive A breaks, you had your photos scattered all over the place. Maybe on drive A only, but also on drive B? Maybe in the cloud? Maybe not? \$\endgroup\$
    – Saaru Lindestøkke
    Commented Mar 24, 2021 at 9:33
  • \$\begingroup\$ @SaaruLindestøkke Multiple copies increase the probability that you will have a copy of the photo after a crashed drive. Not deleting anything is orthogonal to a sound backup strategy. It is also orthogonal to creating a central repository. Nobody minds if you copy all the redundancy onto a single new disk for easy access. Banks need a single source of truth. A shoebox does not. \$\endgroup\$
    – Bob Macaroni McStevens
    Commented Mar 24, 2021 at 14:01
  • \$\begingroup\$ @SaaruLindestøkke Please don’t misunderstand me, there are business cases where removing duplication makes business sense. Most people don’t have a business case. On the other hand, append only is also a sound business approach to managing data. Document search (information retrieval) is a better strategy there than relational or flat file databases. \$\endgroup\$
    – Bob Macaroni McStevens
    Commented Mar 24, 2021 at 14:09
  • \$\begingroup\$ @BobMacaroniMcStevens what software would you recommend for tagging and hiding away the duplicates? I have a ~1:10 duplication rate, I assume you are suggesting something that I could tag one photo/folder and it would replicate that for other copies. Otherwise that would take too much time. \$\endgroup\$
    – Roberto
    Commented Mar 25, 2021 at 2:41
  • \$\begingroup\$ @Roberto I recommend software you are using already. What are you using? \$\endgroup\$
    – Bob Macaroni McStevens
    Commented Mar 25, 2021 at 3:06

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