I dont think is in the curtains that open and close when you press the shutter. Is it inside the lense? Or is just seen in illustrations that show how a camera works? It has nothing to do with "aperture"?
The best way I could find to explain my question is this: The pinhole I am talking about is that orifice where the light goes thru, and an inverted image (upside-down) is created. This orifice must be present in any camera in order for a defined image to form and register on the film or sensor. But I dont think is the aperture, because the pinhole has to be a very small, "punctual" hole? And is the same orifice existing in the first invented cameras , over a hundred years ago. (camera obscura comes to mind)I just would like to know where is this orifice located in modern SLRs