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On this page I found this here:

http://www.timescapes.org/products/

And I don't get it, because 4k Ediition is only 25gb and 4k cinema is 330gb.

What is the difference if both are 4K (4096 x 2304) ?

Could 12-bit (color resolution) make that huge difference in size?

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2 Answers 2

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The simple answer is yes for a couple of reasons:

  • if the number of pixels is the same*, the colour depth can have a huge impact on the size. 12 bit = 4096 in decimal. So if the difference between the two formats is 13.2 (330/25) that could be easily explained as the difference between 8 bit and 12 bit is could be a 16x difference.
  • the content on each of the formats may be different - you have no way of knowing from this product list.

(*there are some differences - see table below from the Wikipedia 4K page)

enter image description here

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  • This is indeed the biggest factor but @Fred42vid is not wrong either, the two versions use two diffrent codecs that compress the video diffrently. He may have used h.264 with Level 5.1 or 5.2, it supports up to 4k. If the bit-depth of both files were the same I would estimate a file size of 60-80GB for the cineform file. That estimate includes chroma subsampling, h.264 would have 4:2:0 or 4:2:2 when using a standard profile, Cineform has 4:4:4.
    – timonsku
    Jan 16, 2013 at 22:15
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It's the compression!

The color resolution is a factor, but not such a big one. In this case the compression is the biggest factor. If you assume that both the 4K Edition and the 4K Cineform contain the same material, 4K Cineform contains more than 13x the information (as stated on the timescapes.org products page).

But is more really better? Cineform states here that for 4K their codec produces a stream between 30 MByte/s up to 90 MByte/s, depending on the color space. This is far more than an average computer can display without interruptions.

So, if you just plan to play back the movie smoothly, choose a smaller format, as timescapes.org offers for 30" or retina displays.

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