Topic: PoP:FS DSi camera unlockable features

I bought an original the Prince of Persia: The Forgotten Sands game for the DSi. In world 1 map, after finishing level 5 was told to activate the camera in the menu and point it to a light source in order to get an unlockable. I dont know what to do. Can you help me understand what I am supposed to do in order to unlock this? Thanks (I have tried activating the function in varied brightness backgrounds, pointing it to TV, light bulbs, sun, and pressing every button and the screen, but nothing)

EDIT: Problem is I cant even snap a shot on the camera, and just keep pointing wont help either, tried all DSi, XL & 3DS.

Take a picture with L/R maybe?

No, that didnt work.

Touch Screen?

I was thinking about picking this game up too. I read online that the DSi exclusives are 4 stages where you they will take your image and incorporate it into the stage. I would try to shoot a picture of something light, but not incredibly bright and hopefully it'd work. Also, are you attempting this on a 3DS? ...I don't know if the few DSi cart titles are compatible with 3DS since I don't have any handy.

@sykotek Problem is that I cant even make the camera function snap a shot, I have tried all the buttons, touch screen and waiting. I have also looked everywhere on the web for how to activate this unlockables without lick, probably because the owners of this game can be counted with the fingers of your hand. That is an interesting info you've brought there, DSi games work fine on 3DS using the camera, but I cant get the unlockables on any DS model, I tried them all.