By: Jesse Korosi, Director of Workflow
I have heard this question of “2.39 vs. 2.40 for features” come up several times during the production stages of jobs and thought I would write a quick post to try to clear some things up!
If you are shooting a movie and delivering to a theatre, the DCP Spec for delivery is actually 2.39.
Here is an example pixel accurate framing chart for the Arri65, framing for a 10% punch in on a 2.40 frame:
This 10% punched in frame is 5904 x 2460, which again is 2.40.
Framing on set at this aspect ratio will be fine and no issues will be flagged here. Online distribution for PIX/DAX type files will be delivered letterboxed to 2.40, no problem. In the offline edit, a matte and punch in can be added to work with the intended 2.40 area, again, no problem. Then on to visual effects, they will work in 2.40 as well.
After we have been on through all of these steps it’s time for our DI. However by this time, the people that made the decision on set to frame for 2.40 have finished their work and are on to their next job!
In comes the final DI. Delivering a final 2K DCP has a resolution spec of 2048×858. Why is this number so important? It’s not 2.40! It is 2.39.
If we were having all of our VFX scaled down to 2K for delivery for the conform and we wanted to maintain EXACTLY what was seen on set and through dailies, editorial, etc., we probably would have done something like this:
The grey area represents maintaining a 10% look around area to the final frame which is great to keep for stabilizing and small re-frames. The red area then represents the actual frame that was being displayed on set and on through editorial.
You will notice the height of the red area is currently 852. If you take 2048 and divide that by 2.4 you actually get 853.333. However, we do not want to use odd numbers when providing framing. Therefore, this has been rounded down to 852.
So with the DCP Spec actually being 2048 x 858, we need to somehow fill these extra pixels before delivering.
We have two options. Add a few black rows of pixels top and bottom of the frame during the DI process, or add in pixels that were technically outside of the intended frame. But, option 2 may not even be an option as there is a great chance your VFX shots delivered to DI were actually hard matted or cropped, so those extra pixels may not even be available.
Adding these black pixels is not a huge deal during the online process. However, it is a step that would ideally be avoided by simply framing on set at 2.39, as the majority of people that choose to go 2.40 instead of 2.39 are not doing it for any type of aesthetics, but rather what they may be used to.