Nikon D70 Noise
The tables below show a series of dark frames with different exposure time and sensor sensitivity, taken at 22° Celsius. The camera settings were: optimize image = normal, long exposure noise reduction = no, image quality = raw, white balance = direct sunlight. Except resizing or cropping and converting from 16bit NEF to 8bit PNG was no further image processing done.
Scaled Full Frame
The 3008x2000 px raw dark frames have been resized to 150x100px for comparison. As one can clearly see, there is a strong noise source in one corner that rapidly increases with long exposures. This is probably caused by the heat of a microchip. After several long exposures one can feel that the camera gets warm. If the heat noise in the image corner has become white, the image cannot be repaired by subtracting a dark frame. The maximum possible exposure time without loosing data depends on the ISO sensitivity.
ISO 200 | ISO 400 | ISO 800 | ISO 1600 | |
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1:1 Center Crop
The table below shows a 150x100 pixel crop in the center of the raw image and should represent the average noise of the CCD chip. One can see that the average noise is not bad, except for the rapid noise increase after one second with ISO 1600. It would be much better if Nikon D70 didn't had this misplaced heat source that causes the bright corner.
ISO 200 | ISO 400 | ISO 800 | ISO 1600 | |
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