# FLUX 3 Video Keyframes: How to Pin Frames, Storyboard Beats, and What the Docs Say Will Drift - Published: 20 October 2026 - Updated: 20 October 2026 - Author: RenderBob team - Category: Technical - Canonical: https://renderbob.ai/blog/flux-3-video-keyframes-guide Runware's FLUX 3 Video docs let you pin up to 10 images by frame index or by timestamp. The page calls that strong guidance, and it marks storyboards and morphs experimental. Black Forest Labs' FLUX 3 Video, as Runware documents it, takes up to 10 images in frameImages. Each image is placed with a frame or a timestamp. The keyframe guide treats each pin as strong guidance, and it tells you to expect drift. ## How a pin is specified frame can be first, last, or a zero-based index counted at 24 frames per second. -1 is the last frame. timestamp is seconds, in hundredths, from 0 to 20. One entry uses one or the other. Sending both is a validation error, and two images cannot share a position. A position past the duration fails validation. Leave the position off and the placement depends on how many images you sent. One image becomes the first frame. Two become the first and the last. Three or more pin the first and the last, with the middle images spaced evenly. Clips run from 5 to 20 seconds. Three or more images with no positions need a whole-number duration. auto is rejected in that case. Runware's model page lists resolution as 720p or 1080p, and it defaults to 720p. The keyframe examples are 720p. frameImages cannot be combined with video continuation. Sending both returns a 422. ## Patterns the guide describes - A single first frame, when the source image is the shot you need to open on. - A last-frame pin, for a packshot or a logo that has to land. - A timestamp for a beat, such as a jump apex at 3.5 seconds. - A two-frame morph, and a multi-image storyboard. Both are marked experimental. Morphs work better when the two frames share camera angle and lighting. ## What the page says will drift Expect small composition drift, leftover props, and motion between distant keyframes that can jump like a timelapse. Storyboards struggle with large subject motion or a big scene change. The guide says to open the prompt by telling the model to use the image as the first frame, match the source aspect ratio to the output, pin the last frame when the ending is the deliverable, keep storyboards simple, and reuse the same keyframe files across takes. Some takes need another roll. ## A speed claim with one source A July MindStudio article described FLUX 3 Video as early access via Discord, with native audio, up to 10 image references, and unreliable image-to-video reference handling at that stage. A daily digest on 20 October lists FLUX 3 Max, a 10-second clip in about 12 seconds, and a 22 times speed advantage over Seedance 2.5. We could not find a second source. The July article makes no speed claim. Treat the Max line as unverified. ## A working test Take two stills from the same scene. Pin them as the first and last frames of a 6-second clip, then add one timed beat. See how far the middle drifts, and keep that keyframe set for the next takes. RenderBob lets you choose local or cloud for each clip and keep the references with the studio. ## What to watch Independent drift tests against Kling 4.0's keyframes, and a primary source for the Max speed line.