Some fps questions

Hi everyone,

I am new to this forum and new to Resolve too. I am a budding cinematographer trying to make my first music video. I had shot some footage at 120 fps 1080p with Sony a6300/RX10 to slow it down in post for slow motion effects. As I read in other posts, I need to create a new project for every frame rate. I had 2 questions

1. I opened a new project for 120 fps but in the project setup I can only set the Timeline frame rate to a maximum of 96 fps (dropbox). Is this a limitation and are there any workarounds?

2. When I drag and drop a clip from the Media Storage window into Resolve, I sometime get a message "The clip frame rate does not match the project frame rate Change? Don't Change? " and sometimes I don't. In what circumstances does Resolve show the message? And also, if I choose 'Don't change' does it mean that I can have a 120 fps clip in a 24 fps timeline?

Thanks in advance for your answers!

Suresh

The project frame rate should match your desired delivery frame rate (assuming 23.976?). There is a slight glitch frame rates higher than 96, as there's no default option for them. If you intend the footage to be slow-motion, set your timeline frame rate to your desired output (let's say 23.976), then open the clip attributes for the 120p clip, set the frame rate to anything else and hit ok, then go back in to clip attributes and set the clip to 23.976 (or whatever your project is set to). This will properly re-I tee peer the footage so that 1 frame = 1 frame.

Worked!! That was wonderful Scott! Thanks a million. Was wondering whether Blackmagic was aware of this glitch. If I am slowing down the clip in this manner, does the Project Settings -> Editing -> Frame Interpolation settings have any impact on how smooth the slow motion is? (When I am using the Change Clip Speed option to slow down the clip, I use Optical Flow as the Retime process and set it in the Inspector -> Retime and Scaling section.)

About my second question, I realized that Resolve was not prompting the message only when the clip is at 120 fps (timeline is set at default 24). When I import clips which are 23.9 or 60 fps, the message pops up. Looks like Resolve is yet to perfectly handle 120 fps.

We can choose how Resolve handles mixed frame rate by following this method from Resolve 12.5 manual, page 85:
You should also choose “Resolve” if you’re editing from scratch in DaVinci Resolve, and your source clips are at different rates than the timeline rate and you would like each of the clips to be speed changed to the timeline rate by default. This option uses the Retime selection you can find on the editing tab. This pop-up menu also appears in the Load AAF or XML dialogs when you import a project.
Only available prior to importing media into a project)

Was wondering whether Blackmagic was aware of this glitch.

My guess is "yes."

Reconciling frame rates at other than conventional fps becomes a judgement call, and there are legitimate reasons for 60 fps+ to be held at that frame rate -- like for real time HFR workflows.

If you really want 60+ to play back at the native sequence base for slow motion, that's an elective that you need to tell Resolve about, and obviously it works. Fundamentally, almost all of the grade applications are based on sequential-frame workflows -- .dpx, .tif, and so on, which don't have an intrinsic frame rate. That gets assigned by the project settings. Interpreting media containers like .mov or .mxf does pay attention to the fps header metadata (at least now it does, in most cases) but it may still count absolute frames from the 'trim-in' point and just iterate the count -- one frame, another frame, another frame... wrt the project rate. Needless to say this works very well when the fps matches the timeline, but not at all if there is a difference or a time warp/re-map applied. We've progressed a lot in the last 5 or 6 years, at least non-linear timewarps are claimed to be supported now. (But its still a good idea to bake them out.)

This also goes some distance in explaining why variable frame rate goes sideways immediately and Long-GOP is unwieldy.

jPo