In Harry Potter and the Chamber of Secrets, Harry meets a boy named Colin. He wanted to take Harry's picture, so that he can prove to everyone that he has actually met him. Later, he talks about developing the picture.

and a boy in my dormitory said if I develop the film in the right potion, the pictures'll move

What potion is needed to develop pictures, so that they can move?

  • Haha! Colin should have gone for the Selfie! :D Jan 14, 2015 at 17:38

1 Answer 1


I don't think Rowling ever gave that potion a name- in fact, the quote you gave above was the only mention of it in the series.

Here's a little something JK Rowling had to say about it (originally posted on her website, reposted at the MuggleNet.com forums):

JKRowling's website, F.A.Q.
As a vast number of people have pointed out to me in the last twenty four hours (some of them related to me by ties of blood) Colin DID develop a photograph from his camera in 'Chamber of Secrets' (my previous answer stated that he never did so).

Cameras, like radios (or, as the wizards call them 'wirelesses' – they're always a bit behind the times when it comes to Muggle technology) do exist in the wizarding world (there's a radio in the Weasleys' kitchen and we know there are cameras because of the moving photographs you see everywhere). Wizards do not need electricity to make these things work; they function by magic, but in the case of such objects the wizards liked the Muggle invention enough to appropriate the idea without adding cumbersome plugs/batteries.

I have an old notebook in which it says dev sol (potion) magic [indecipherable word] photos move. Adept as I am at interpreting my old scribbles, I can tell you that the original idea was that wizards would use a magical developing potion to make their photographs move.

SO... as Colin's batteries can't work in Hogwarts, clearly his camera is running off the magical atmosphere and he is then developing his photographs in the magical potion that causes the figures therein to move. All of which goes to show that Colin has a lot more initiative than I ever realised.

dev sol seems to be shorthand for developing solution.

  • batteries can't work in Hogwarts, clearly his camera is running off the magical atmosphere - I wonder, in the books did Colin's camera have a flash? If not, I am not then it wouldn't really need batteries for anything. Older cameras even disposable cameras you get these days are purely mechanical. If you properly light the area with magic, you wouldn't need the flash, and so you wouldn't need any electricity at all. Also better cameras can compensate for the lack of perfect light by modifying the exposure time.
    – Zoredache
    Jan 14, 2015 at 19:33
  • 2
    Even in the muggle world, you don't need batteries to have a camera flash. We muggles use loose magnesium powder (very old school) or magnesium wire in a single-use disposable bulb.
    – Joe L.
    Jan 14, 2015 at 23:23
  • Wiki article with info on old-school flash photography. If anyone's curious.
    – Joe L.
    Jan 14, 2015 at 23:33

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