Disk Space for DPX

Hi

Does anyone know how much disk-space around 10mins worth of 35mm scanned at 4K to DPX would take up?

Thanks!

K

When working in 4K, the rule of thumb is a terabyte per reel. That's your short answer. The actual math follows:

A full-aperture 4K scan of 4-perf Super 35 will come in at 4096 x 3112 pixels. Each pixel is stored as four bytes (ten bits for three color channels plus two bytes of padding), and a DPX file has an 8,192-byte header on it. So a full-aperture scan will be 50,995,200 bytes, which is roughly 48.6 megabytes.

A reel is a thousand feet, or 16,000 frames. (Ten minutes would be 14,400 frames.)

Multiplying that out, you get 815,923,200,000 bytes, or roughly 760 gigabytes, for a thousand-foot reel. Since you never scan every single frame on a reel (you skip the leader and so forth), you can round that down to 750 gigabytes and be more or less okay, most of the time. It's easier to do the arithmetic in your head if you round up to a terabyte though, plus it gives you some margin for error.

Your actual requirement will be smaller if you're not scanning the full Academy frame. If you're hard-matting, or cropping out an optical soundtrack, or scanning a frame of 3-perf Super 35 or 2-perf Techniscope, you'll have fewer pixels per frame, so your DPX files will be correspondingly smaller.

If you're curious, 2K full-aperture scans come in just slightly over 12 MB per frame, or roughly 200 gigabytes per reel. Which is why 2K is still by far the preferred format.

At this data size, is it an uncompressed process?


Jeff Harrell Wrote:
-------------------------------------------------------
> When working in 4K, the rule of thumb is a
> terabyte per reel. That's your short answer. The
> actual math follows:
>
> A full-aperture 4K scan of 4-perf Super 35 will
> come in at 4096 x 3112 pixels. Each pixel is
> stored as four bytes (ten bits for three color
> channels plus two bytes of padding), and a DPX
> file has an 8,192-byte header on it. So a
> full-aperture scan will be 50,995,200 bytes, which
> is roughly 48.6 megabytes.
>
> A reel is a thousand feet, or 16,000 frames. (Ten
> minutes would be 14,400 frames.)
>
> Multiplying that out, you get 815,923,200,000
> bytes, or roughly 760 gigabytes, for a
> thousand-foot reel. Since you never scan every
> single frame on a reel (you skip the leader and so
> forth), you can round that down to 750 gigabytes
> and be more or less okay, most of the time. It's
> easier to do the arithmetic in your head if you
> round up to a terabyte though, plus it gives you
> some margin for error.
>
> Your actual requirement will be smaller if you're
> not scanning the full Academy frame. If you're
> hard-matting, or cropping out an optical
> soundtrack, or scanning a frame of 3-perf Super 35
> or 2-perf Techniscope, you'll have fewer pixels
> per frame, so your DPX files will be
> correspondingly smaller.
>
> If you're curious, 2K full-aperture scans come in
> just slightly over 12 MB per frame, or roughly 200
> gigabytes per reel. Which is why 2K is still by
> far the preferred format.

DPXs are not compressed, no.

Thanks for the info Jeff! Incase you're curious it's 35 Anamorphic we'll be scanning.

K