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Comment by charlief | Hacker News Reader

Good idea, but works most effectively when:

(1) Various encode/decode steps along to publishing the photo online don't corrupt EXIF data

(2) Thief isn't sophisticated to wipe/disable EXIF data. Many cameras shoot in a proprietary, higher-bit format and give you a fairly obvious wizard option on a desktop tool to include/exclude the EXIF data.

(3) Thief will use the camera, not sell it immediately into a second-hand market.

(4) Even if your camera is supported, it has to be configured to record EXIF data by both you and the thief. Some proprietary formats are fairly raw and don't always include EXIF-derivable data by default.

This will get some adoption because what other option do users have, but it will be interesting to see how many uploads convert to a lost camera being recovered/thief being apprehended. If users had the ability to leave a testimonial when there is some kind of closure, you could derive a metric of success.

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1) Libraries used to manipulate images tend not to break EXIF data, and many site do not use any encoding at all.

2) Seriously, do you think that a common thief cares about EXIF, let alone know?

3) I have not seen a camera which does not write EXIF -- more probable problem is that it does not write camera serial number.

4) What is the difference? You have similarly small chance of retrieving it, no matter whose possession it is in at the moment.

Most camera's maybe. I'd be interested to see what phones write EXIF, as I would guess phone theft/loss is a more common occurrence. I tried it with my Nexus One but unfortunately it seems that it doesn't log serial numbers in the EXIF data.

Most modern phones do, although as I already pointed out, the real problem phones/cameras not writing serial numbers, not EXIF data as a whole.

Almost every modern smartphone writes EXIF - including Android and iOS.

In fact, EXIF is so common, and so poorly understood by thieves, that your only main fear is image hosts stripping EXIF, or the firmware failing to include serial in EXIF (which is less likely the more expensive the camera).

3) was partly true for me. No serial number is written.

Yup--my camera (Canon 60D) was listed, but when I used a photo that had been exported with Lightroom, it couldn't read the serial number. Only when I gave an original JPEG did it have any success, and it didn't end up finding any photos, since anything I've uploaded has been exported through Lightroom.

I tried it with an old Canon Rebel XTi photo that had gone through Lightroom and flickr. "exiftool" shows a serial number in the image, but the web site does not.

I downloaded the "original" size from flickr - resized flickr images seem to drop most of the exif info, and the "exif info" displayed on the web site no longer shows serial numbers.

I noticed the same a few days ago when I tested it. All my JPGs are exports from Lightzone and there's no serial, my originals are all RAW, so - no luck for those who don't shoot jpeg/raw+jpeg.

You might have "minimize embedded metadata" checked in the export options; uncheck it and I bet the serial will survive the export. Also, if you want more control over exported metadata, Jeffrey Friedl made a plugin[1] for that. I haven't used this particular plugin; I do however use his flickr and geocode plugins, and they're both great.

1) http://regex.info/blog/lightroom-goodies/metadata-wrangler

Lightroom has an export option called "Minimize metadata" that strips a lot of EXIF out.

You have no idea what you're talking about.

- 99.9% people shoot JPEG (which has EXIF enabled by default in pretty much every camera).

- Most DSLR owners don't shoot RAW and don't know what EXIF is.

- Most RAW formats contain EXIF information (at least for major brands).

- Most graphic editors do not destroy EXIF data.

- Even if a thief sells the camera, buying stolen stuff is illegal, so you can get your camera back (it's buyer's problem)

I interpreted this

(1) Various encode/decode steps along to publishing the photo online don't corrupt EXIF data

As referring to online photo-sharing sites which will strip out EXIF data for privacy reasons, like Flickr/Facebook/Imgur.

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