This has been one of my favorite and most populartricks for birthday parties. I could be adapted for other activities. I use an old Polaroid camera, the old stanless steel ones. No longer made but you may find one in a garage sale. These cameras really look good.
I describe this camera to my audience as not one of those old fashioned digital camera but a new Magic Camera.
I ask the parents for a digital pix of the child. Then using Serif Photo Plus (or a photoshop type program) to remove the child from the background. I insert the child into a template.
The year and name is added to the final pix.
I then show the “Magic Film” and insert it into the camera. You will need to prepare the camera by opening it up and tape a black paper into the chamber so the “film” will remain hidden when the picture door is opened.
The final picture is placed in the camera behind the picture door.
Do your patter about what you are doing and have the child put the magic film in the camera. Take the picture and have the child open the door and take out the picture.
The pictures show the pix and film showing from the back. Probably logic says they should be the other way. I showed it this way for easy viewing but you may want to put it the other way.
I often show a big pix of the castle as a part of the patter leading up to taking the pix. I usually print 2 copies because the parents want one and the one the child gets will get beat up as they show their friends. I find it wise to make this the last thing you do. The kids will all want to see the pix and it will be hard to do anything else.