A historical video-production archive needs to distinguish the Gen-4 family from Gen-4.5. Gen-4 was an image-led generation workflow in which a reference image was required; it is not accurate to copy Gen-4.5’s text-only specifications backward into it. Old video tutorials remain useful, but only when their model, plan and period are identified.
What the older model actually documented
Runway’s Gen-4 documentation states that Gen-4 and Gen-4 Turbo produce five- or ten-second video outputs from an input image plus prompt. Both specify 24 fps. The published outputs include landscape 1280×720, portrait 720×1280, square 960×960 and several other crops. Gen-4 cost 12 credits per second, whereas Turbo cost five credits per second. Thus a five-second Gen-4 attempt cost 60 credits and a Turbo attempt 25 under that published rate card.
The critical difference for teams migrating old project files is the input contract: an image was not an optional aesthetic preference in Gen-4, it was required. A pipeline that only stores the written prompt cannot reconstruct its key creative input. Preserve image file hashes, permission records, framing and crop settings beside each prompt, seed and output.
Where Turbo fits
A cheaper iteration model is useful for checking whether a broad motion concept reads. Suppose a character must turn toward a window and reveal a skyline. A team can test the action at the lower Turbo rate, then choose whether the scene warrants spending more on standard Gen-4 or migrating to a newer family. This is a budgeting workflow, not a claim that Turbo and standard versions render equivalent frames from the same seed. Runway describes fixed seeds as helping produce similar motion, not guaranteeing a pixel-perfect repeat.
Preserve version-specific provenance
For an archival record, store model ID, model family, invocation surface, ratio, FPS, nominal credits, generated output length, generation date and source policy date. The public help center now labels Gen-4 an older generation and links creators to Gen-4.5 and Edit Studio. That is enough to mark this page historical rather than advertise Gen-4 as the preferred live route. A future importer should not collapse Gen-4, Gen-4 Turbo and Gen-4.5 under one evergreen specification.
Practical handoff
Export original MP4 files with metadata and keep source stills separate. Inspect visual continuity at joins, remove unused tests with clear retention rules and recheck commercial rights for inputs. If the job depends on new text-to-video modes, consult the Gen-4.5 record instead of assuming a legacy feature gained new controls automatically.
Worked production example
An archived 2025 campaign may contain only a PNG, prompt and finished MP4. Before migrating, reconstruct the scene’s aspect ratio and required input-image crop. A creator cannot fairly reproduce a Gen-4 shot using the text prompt alone if the essential image is missing. Mark it as an incomplete archival reproduction, not a failure of the newer renderer. If the old footage is acceptable and licensed, keep it; regenerating merely to modernize a model label risks changing approved characters, typography and timing.
Relevant alternatives and trade-offs
For native-audio generation assess Gemini Omni Flash; for sophisticated HDR/VFX handoff inspect Ray3.2; for exact on-screen graphics use a conventional compositor.