When I was in school, the photo imaging principle of a camera was taught by the teacher in the high school chemistry class.
To put it simply: using the property of silver bromide to decompose when exposed to light, through the camera lens, bright objects will reduce the silver bromide on the film into silver, while dark objects cannot be restored. After the film is developed, , the scenery becomes a negative film with the opposite light and dark to the subject on the film. Then go through the darkroom, use a lamp to illuminate the negative film, and shine it on the photographic paper through the negative film. The silver bromide on the photographic paper will also be reduced to different degrees according to the intensity of the light. A negative becomes a positive, and the washed out photographic paper will be The same light and dark photos as the scenery we saw.
Half a century ago, Polaroid introduced a camera that pressed the film and photo paper together, with developing chemicals in between. After taking the photo, the medicine works to transfer the unreduced silver salt on the negative to photographic paper, and after processing, the positive film is obtained. Because photos can be obtained within minutes of taking a photo, the camera has been used in many fields in the more than half a century since its introduction. Back then, many vendors in Tiananmen Square used this kind of camera to drum up business. Of course, they are also found in many scenic spots.
The camera has a simple body structure, which is equivalent to the simplest point-and-shoot camera; the photo paper is expensive, and only Polaroid produces it. This involves a lot of patent issues, and only Japan's Fujifilm has produced it. .
The disadvantage of this kind of disposable camera is that the photos are easy to expire, the color of the images is not guaranteed, and the color of the photos will change over time.
More than ten years ago, due to the emergence of digital camera technology, the scene after taking the photo can be seen immediately and printed out very conveniently as needed. This kind of one-time imaging Polaroid suddenly lost its existence. Meaning, Polaroid Company declared bankruptcy in 2001.
Although the camera on hand is gone, there are still two boxes of useless films. Keep it as a souvenir.