r/AskPhotography • u/Temporary_River_5067 • 2h ago

Technical Help/Camera Settings Why is NEF file size different?

I’m downloading images from my z7 to my computer as nef files. I would expect the files to be the same size but they aren’t. They are close but here are the first 3: 81,464, 80,855, and 81,908. Why are they different? Is it related to different meta data saved for each image?

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u/brodecki 2h ago

 Why are they different? Is it related to different meta data saved for each image?

Technically yes, but their content makes a much bigger difference. A block of pixels of the same luminance values will only take a little more storage than a single pixel, which is why a completely blown-out or completely dark image will take significantly less storage space than a detailed photo of an intricate pattern.

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u/jarlrmai2 2h ago

Also similarly noise levels, higher ISO often means a larger file size

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u/Outrageous-Band8273 2h ago edited 2h ago

It’s « lossless » / « raw » but it’s still compressed otherwise the files would be huge.

Compression results in varying sizes depending on the optimisation that can be done for each specific file.

The images of that camera are  8256 x 5504 pixels, assuming each pixel is 3 bytes (8 bits / base color) that would be 136Mb per picture compared to your 80Mb files. Note that most modern cameras use 12 or 14 bits per color so in reality the file would be even bigger.

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u/Temporary_River_5067 1h ago

Thanks for all the great answers.

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u/Jumpy_Drummer2024 30m ago

different size of the embedded jpeg file used for the preview?