LUTs (Look-Up Tables) are how video color grading gets done. A .cube file is a small text file that maps every input color to a new output color, applied uniformly across every frame of your video. Editors use them for everything from log-to-Rec.709 conversion to film emulations to a specific look you saw on a YouTube video.
For years, applying a LUT meant opening DaVinci Resolve or Premiere on a laptop. That is still the right tool for a full color grade, but for most creators the question is simpler: how do I get this look onto my iPhone footage without opening a laptop? The answer is yes — ReelClip imports .cube files from the Files app and applies them on-device.
Two kinds of LUT, and which to apply first
LUTs come in two broad categories, and the order you apply them matters:
- Camera-transform LUTs. Convert log gamma footage (DJI D-Log, Apple Log, Sony S-Log, HLG) into a displayable color space like Rec.709. These must be applied first, directly on the raw log footage.
- Creative LUTs. Apply a stylistic look on top of already-normalized footage — a film emulation, a warm cinematic grade, a desaturated action look. These go on after the camera transform.
Applying a creative LUT to raw log footage gives unpredictable results. The creative LUT assumes it is being fed normal-range color, not a flat log signal. ReelClip handles this correctly by always applying the camera transform first, then letting you stack the creative look on top.
The on-device workflow
Step 1: Get your LUT file
LUT packs usually arrive as a ZIP of .cube files. Save them to your iPhone — the Files app works, as does iCloud Drive, Dropbox, Google Drive, or anywhere else iOS can read. The file just needs to be reachable from the Files picker.
A few popular free LUT packs to start with:
- DJI's official D-Log to Rec.709 conversion LUTs — available on the DJI website for each camera model.
- Apple's Final Cut Pro LUT packs — designed for Apple Log and convertible to .cube.
- Free LUT packs from Lutify.me, SmallHD, and others.
Step 2: Import into ReelClip
Open ReelClip, import the video you want to grade, and pick the matching camera color profile (DJI D-Log, DJI D-Log M, DJI D-Log 2, Apple Log, Apple Log 2, or HLG). ReelClip applies the correct built-in camera transform for that profile.
Step 3: Import your .cube file
In the Look panel, tap Import LUT and pick the .cube file from Files. ReelClip parses the file, validates it (most are 17×17×17 or 33×33×33 cubes), and adds it to your on-device LUT library. The file stays on your iPhone — nothing is uploaded.
Step 4: Apply and adjust strength
Select the LUT from the list. ReelClip applies it on top of the camera transform. Most creative LUTs look too strong at 100%, so use the strength slider to dial it back — somewhere between 60% and 85% usually hits the right note. You can preview the result on every frame in real time.
Step 5: Export the graded clip
Save to Photos. The output is a standard Rec.709 video file with both the camera transform and your creative look baked in. Ready to post, share, or edit further.
What this gets you
The traditional LUT workflow was: copy LUT file to laptop, copy footage to laptop, open Resolve, apply LUT, render, copy back. Hours of work for one clip.
The on-device version is: import LUT once into your phone's library, then apply to any log footage you shoot, forever. The library persists across sessions, so once you have imported a LUT you like, it is one tap to apply to your next clip.
What to do next
If you are grading DJI footage specifically, see DJI Osmo Pocket color grading on iPhone. For the broader DJI workflow from import to post, see how to edit DJI Osmo footage on iPhone.