Here's a random question:
How do you (the photographer) conclusively prove the date on which a photo was taken, within the photo itself, using an easily-repeatable method?

I was watching a film where a character was kidnapped and the baddies took a polaroid with the current day's paper in shot... but that would only work for today. If you used the same photo tomorrow, there would be no way to tell if the photo had been taken today (but with yesterday's paper) or yesterday.

Things like this keep me awake at night. I'm going down to my local pub, hopefully someone will figure it out by the time I get back :-D

EDIT: I'm not planning any kidnappings btw. However, this may change if an answer materialises...
( chart cat has an itch, Fri 1 Aug 2008, 20:39, 11 replies, latest was 16 years ago)

If it's a JPG file
You can right click on it, go to Properties, then Summary and it'll tell you all sorts of interesting things about it :)
(jamesthegill opens new tabs with his scroll wheel, Fri 1 Aug 2008, 20:50, Reply)

I don't know that there's a way to do so conclusively.
I mean, I can take an image, copy it to a machine, manually set the date to 1980, re-save the image and it'll claim it's 18 years old...
( The Resident Loon Not a demographic. Do not measure., Fri 1 Aug 2008, 21:03, Reply)

@Loon
Shirly 28?
(Pretty strangers and promises, Fri 1 Aug 2008, 21:32, Reply)

Gah. You're right.
Sorry- nipping in here between researching stainless steel thrust bearings. Ah well...

I'm REALLY irritated that I can't find anyone making thrust bearings with ceramics! Stainless steel is just not strong enough, and carbon steel would rust solid inside a month underwater...
( The Resident Loon Not a demographic. Do not measure., Fri 1 Aug 2008, 21:34, Reply)

Create a catastrophe in the background
which would only occur on one particular day
(Ethelred is watching cheese grow, Fri 1 Aug 2008, 21:43, Reply)

I guess the question is
are you trying to prove that the pic is old or new? Proving it's recent with a newspaper or TV in the shot is easy. Proving it's old is impossible.
( The Resident Loon Not a demographic. Do not measure., Fri 1 Aug 2008, 21:48, Reply)

Thanks for the suggestions so far!
@james... yep, but anything digital is relatively easy to manipulate without leaving a trace. I'm pretty sure the EXIF data embedded in a jpeg can be changed.

@Ethelred: A fine suggestion, but not an easily-repeatable one. Incurring the wrath of the masses would probably mean I'd shortly end up in the slammer, which would limit the usefulness of that method.

@TRL: Prove that it's of a specific date in the past. The polaroid method works for 'today' but for any date in the past it isn't reliable.

It's a curious conundrum, eh? Some inventors post themselves a vacuum-sealed copy of their design work via recorded delivery and leave it unopened, in case a court case comes up in the future. I guess I'm looking for something like that, which might prove conclusively that a photo had been taken at a particular point in time.

Actually, maybe that would work... you could take the photo and get a copy made (digitally, developed or whatever) and then post it to yourself in a sealed envelope via recorded delivery. What a pain in the arse that would be though, eh?

I don't even have an application for this... it's just something that I couldn't resolve in my own head!
( chart cat has an itch, Fri 1 Aug 2008, 22:32, Reply)

I heard about a chap once
who would paint things that he saw in dreams and thought were predictions of future events. He would then go to the bank and stand infront of the cashiers where they have the time and date clock jobbie.
( Mrs Entity is in hiding., Sat 2 Aug 2008, 1:50, Reply)

what you need is
a blemish/pixel or a mole, and a doctor capable of removing such a mark, or at least certifying that the removal took place prior to the date in question.




its ball park but beautiful
(Escaped_Nubian, Mon 4 Aug 2008, 0:48, Reply)

Posting stuff to yourself doesn't work
If I post myself an empty, unsealed envelope, I can keep it until I need it and stuff whatever I like in there. Voila! One modern thingummy, apparently delivered three weeks ago.
(ThomsonsPier consumes, Mon 4 Aug 2008, 12:05, Reply)