• Compression Techniques

  Film to DPX question

  Posted by Mohammad Tavakoli on February 13, 2013 at 8:25 pm

  Hi,

  I’m currently working on a student film that’s in pre-production and will be shooting over the summer. We will be shooting the film on super 16mm film. I had a question about digitization since I’m fairly new to it.

  Everything I have worked on before was transferred at 422 but for this project I would like to have as much data possible for color grading since we have access to free Resolve suites through the school.

  I have heard that transferring to DPX would give us the most amount of data to begin with. Then we can get 422 files for editing out of resolve and come back to the original files for color grading and mastering. What I couldn’t understand is that if DPX is a single frame or a moving image. I assume it’s a combination of single frames that would be put in motion–just like how jpeg can be.

  Also, to get log footage would I have to just request it from the lab or is that a completely different type of transfer from linear footage.

  I would really appreciate it if someone could explain this to me or refer me to a link that explains it.

  Thank you!

  Jeff Greenberg replied 13 years, 2 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Jeff Greenberg

  March 15, 2013 at 12:21 pm

  Upsampling to DPX won’t make a marked advantage in your workflow, but will vastly increase file sizes and time/cost.

  Basically, that’s what’s wrong, you’d be upsampling. Imagine taking an SD file and blowing it up to HD. You still only have the original data. You wouldn’t be getting any benefit/colorspace advantages to going from 10 bit ProRes to 16 bit DPX; especially since Resolve is 32 bit float internally.

  You need to retransfer the film as DPX files instead of ProRes.

  DPX – is a series of stills. All a QuickTime file is (in this case) is a container. You can actually open QT, point at a folder of sequential stills and have it ‘playback’ as a video file.

  DPX can hold more steps between black and white than ProRes can, if the source supports it and that’s dependent on the transfer. Since you didn’t do your original transfer this way, there isn’t measurable benefit in doing so after the fact. Garbage in/Garbage out (GIGO)

  Feel free to follow up if you have specific questions!

  Best,

  Jeff I. Greenberg
  Author/Master Instructor/Speaker/Consulting
  My contact info and more

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