BRAW 3:1, 5:1, 8:1, and 12:1 are Constant Bitrate compression choices. The number describes the approximate relationship between an unprocessed frame baseline and the compressed recording stream. A lower first number means less compression, more recorded data, and greater demand on media. A higher number means smaller files and longer card time.
The setting is not a simple quality ladder where one option is always correct. The useful question is: which setting preserves enough detail for the shot while keeping the media and post workflow reliable?
What the ratio means
At 3:1, the stream retains roughly one unit of data for every three units in the baseline. At 12:1, it retains roughly one for every twelve. That makes 3:1 about four times the data rate of 12:1 when resolution and frame rate stay constant.
The ratio is based on image data, not the final file’s exact byte-for-byte reduction. Container information, metadata, audio, and implementation details add overhead. This is why a ratio-based formula should be treated as an estimate and checked against camera-specific storage tables.
Side-by-side behavior
| Setting | Relative data | Typical planning priority | Main cost |
|---|---|---|---|
| 3:1 | Highest | Maximum retention for demanding shots | Fast media, short card time, large backups |
| 5:1 | High | Strong quality with more manageable storage | Still data-heavy at high resolutions or frame rates |
| 8:1 | Moderate | Longer rolls and practical everyday acquisition | Less margin for extremely fine or noisy detail |
| 12:1 | Lowest | Maximum capacity and predictable record time | Highest compression in the Constant Bitrate group |
This table deliberately avoids assigning a genre to each setting. A documentary may contain detailed landscapes and low-light noise; a commercial may be a clean talking head. Image complexity matters more than the label on the production.
BRAW 3:1: when data is cheaper than uncertainty
3:1 is the most data-intensive Constant Bitrate choice in the common group. It is appropriate when the footage is difficult to repeat, the frame contains fine texture, the image will undergo heavy manipulation, or the production has deliberately budgeted for the larger data path.
Examples include VFX plates, greenscreen edges, product details, wide landscapes, practical effects, and shots with dense motion or noise. This does not mean every such shot visibly improves at 3:1. It means the production is choosing more recorded information as a risk-management decision.
The cost expands through the workflow. Four times the data of 12:1 means roughly four times the source capacity, copy time at the same transfer speed, backup capacity, and archive requirement. If the media team cannot keep pace, the “highest” recording setting can create a less reliable production.
BRAW 5:1: a quality-led middle position
5:1 is often a practical high-quality setting because it preserves substantially more data than 8:1 or 12:1 without reaching 3:1 volumes. It works well when image quality is important but the project still needs realistic card turnover and post storage.
Use 5:1 as a candidate, not a default rule. Test it with the real scene. Hair, foliage, confetti, rain, fabric, fine architecture, smoke, and underexposed noise can expose compression behavior that a clean test chart will not.
At high frame rates, even 5:1 becomes demanding. Moving from 24 fps to 60 fps multiplies the stream by 2.5. A setting that is comfortable at normal speed may exceed a card, cable, or offload plan in slow-motion work.
BRAW 8:1: capacity without jumping to the maximum ratio
8:1 reduces the data rate enough to extend record time meaningfully while keeping a moderate Constant Bitrate profile. It can be a strong fit for interviews, events, documentary coverage, and general shooting when the scene has been tested and the production needs longer rolls.
Its biggest advantage is operational. More minutes per card can reduce media changes during ceremonies, performances, interviews, or remote work. Smaller originals also shorten offloads and lower backup cost.
The tradeoff is less data for fine image structure. If the footage will be heavily reframed, keyed, denoised, sharpened, or pushed in the grade, compare 8:1 with 5:1 using the intended finishing path—not only an ungraded monitor image.
BRAW 12:1: predictable and storage-efficient
12:1 provides the smallest files among these Constant Bitrate settings. It is useful when long continuous recording, limited media, fast turnaround, or large camera counts dominate the plan. Under controlled conditions, it can make RAW-oriented capture possible on a storage budget that would otherwise force a different codec.
Smaller does not mean “bad,” and large does not mean “automatically visible.” Many images compress efficiently. The risk increases with scenes that are noisy, highly detailed, fast-moving, or intended for aggressive post work.
The responsible way to use 12:1 is to test the difficult part of the project. Shoot the darkest expected lighting, busiest texture, strongest motion, and heaviest intended grade. View the result at delivery resolution and inspect motion, edges, noise, and texture—not only paused frames at extreme zoom.
A numeric example
For 6K 6144 × 3456 at 30 fps, Blackmagic Design publishes representative Constant Bitrate storage rates of approximately:
- 323 MB/s at 3:1
- 194 MB/s at 5:1
- 121 MB/s at 8:1
- 81 MB/s at 12:1
At those rates, one minute before a safety buffer is roughly 19.4GB, 11.6GB, 7.3GB, or 4.9GB respectively. A two-hour recorded day would be about 2.33TB at 3:1 and 0.58TB at 12:1 before retakes, multi-camera multiplication, filesystem overhead, and backups.
The BRAW storage calculator lets you change frame rate and duration, then add the production buffer explicitly.
How to choose a setting
Use a short test matrix instead of a vague quality debate:
- Record the most difficult expected scene at 3:1, 5:1, 8:1, and 12:1.
- Keep exposure, lens, lighting, and framing identical.
- Apply the intended color-management and grading workflow.
- Add the transforms the real project needs: denoise, stabilization, keying, reframing, or sharpening.
- Compare at the actual delivery size and viewing distance.
- Calculate the full-day data, two working copies, archive, and offload time for each acceptable option.
- Choose the smallest reliable setting that still passes the image test—or the highest-quality setting the entire pipeline can safely support.
That last condition matters. A codec setting is only successful if the camera records it without dropped frames, the crew can offload it before cards run out, the backups finish before source media is cleared, and post can play it with the required number of streams.
Do not confuse ratios with Constant Quality labels
Q0, Q1, Q3, and Q5 are not additional points on the same ratio scale. They allow the bitrate to vary with scene complexity. A Q setting can produce a range that overlaps several Constant Bitrate settings. If predictable card time is essential, ratios are easier to budget. If the encoder should spend more data on difficult frames, a Q mode may be preferable.
The best BRAW compression setting is therefore not a universal number. It is the setting that passes the project’s image test and the production’s data test at the same time.
Sources and calculation notes
- Blackmagic Pocket Cinema Camera technical specifications: camera-specific formats and storage-rate reference tables.
- Blackmagic RAW overview: manufacturer information about the codec and encoding modes.
- BRAW Planner methodology: the estimation formulas, unit conventions and limitations used on this site.
Workflow suggestions in this guide are planning guidance, not a claim that a particular camera or drive has been tested by the author.
Use the BRAW storage and recording-time calculator to model your exact resolution, frame rate, compression setting, safety buffer, and media capacity.