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<blockquote data-quote="Felisek" data-source="post: 375523" data-attributes="member: 23887">To be more precise, the amount of information recored in a long exposure is similar to that from a short exposure. During an exposure pixels convert arriving photons into charge, which is accumulated in a special element. When the shutter is closed these charges are read by camera's electronics. I might be wrong, but I don't thing camera is recording or processing any information when the shutter is open.After a long exposure the camera takes a blank picture (with the shutter closed) of the same exposure time as the main picture. This takes time: as you said, if you take a 30-s exposure, the camera will take another 30-s blank exposure afterwards. This blank frame is used to measure noise caused by the heat in the sensor. It is a different type of noise than the high-ISO noise, it makes parts of the frame brighter. Then, the blank frame is subtracted from the image, I don't suppose this process is going to take much time in a modern camera.But you are right, the camera is busy for a while after taking a long exposure and will not take another shot.</blockquote>

[QUOTE="Felisek, post: 375523, member: 23887"] To be more precise, the amount of information recored in a long exposure is similar to that from a short exposure. During an exposure pixels convert arriving photons into charge, which is accumulated in a special element. When the shutter is closed these charges are read by camera's electronics. I might be wrong, but I don't thing camera is recording or processing any information when the shutter is open. After a long exposure the camera takes a blank picture (with the shutter closed) of the same exposure time as the main picture. This takes time: as you said, if you take a 30-s exposure, the camera will take another 30-s blank exposure afterwards. This blank frame is used to measure noise caused by the heat in the sensor. It is a different type of noise than the high-ISO noise, it makes parts of the frame brighter. Then, the blank frame is subtracted from the image, I don't suppose this process is going to take much time in a modern camera. But you are right, the camera is busy for a while after taking a long exposure and will not take another shot. [/QUOTE]

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