KNOWLEDGE MAP · REFERENCE

Do not guess. Check in order.

26 recurring questions about files, colour and Resolve. Start with a symptom: establish what is known and which variable to check next.

Keep the definition, the test and its limitations together.

CHECK DESK / 02A next check, not a verdict
Source → Processing → File → View01 / SOURCESource02 / PROCESSINGProcessing03 / FILEFile04 / VIEWView

SELECTED STAGE / Source

Check what was recorded and what was assigned on read. Appearance alone cannot establish unknown encoding.

EVIDENCE INCOMPLETE

First establish source interpretation and re-import conditions. A symptom alone does not identify the cause.

Open the relevant answer ↗
No file is uploaded or analysed.
COLOR SCIENCE / 02 / REFERENCE

A reference, not an automatic diagnosis.

On this page ↓

01 / QUESTIONS

Find the question. Check the conditions.

The explanation, the next check and what it does not prove.

01
Fundamentals

Why can two Rec.709 files look different?

Because the Rec.709 label does not describe the whole playback chain. Transfer/display assumptions, video/full range, metadata tags, OS colour management, monitor calibration and viewing environment all affect appearance. Compare the signal state and display path, not only the gamut name.

NEXT CHECK

Compare one frame before export and after re-import with explicitly verified interpretation.

LIMIT OF THE CONCLUSION

Do not grade a master for an arbitrary player using a blanket compensation curve.

02
Fundamentals

Are sRGB and Rec.709 the same thing?

They share RGB primaries and a D65 white point, so their gamut geometry is the same. Transfer/display conventions and typical viewing contexts differ. An sRGB file is not automatically a correct Rec.709 master merely because the primaries match.

NEXT CHECK

Check the graphic's source profile and the function expected at its project input.

LIMIT OF THE CONCLUSION

Matching primaries do not imply matching nonlinear-code interpretation.

03
Fundamentals

Does Rec.2020 automatically mean HDR?

No. Rec.2020 defines wide-gamut primaries and part of the UHD signal framework. HDR commonly uses BT.2100 with Rec.2020 primaries plus PQ or HLG and an appropriate rendering/display context. Rec.2020 SDR is possible, and HDR requires more context than a gamut label.

NEXT CHECK

Read transfer characteristics and the delivery specification alongside primaries.

LIMIT OF THE CONCLUSION

10 bits, UHD and Rec.2020 individually do not prove that a file is HDR.

04
Fundamentals

Why does Log look grey and flat?

Log is a scene-oriented encoding, not finished display rendering. If its code values are shown directly on an SDR monitor, contrast and saturation look low. Use the correct input interpretation and a viewing/output transform rather than an arbitrary contrast boost.

NEXT CHECK

Record camera, recording mode, exact log generation and matching gamut.

LIMIT OF THE CONCLUSION

Do not assign log because the image looks grey, or add a technical LUT over an existing transform.

05
Fundamentals

Do I need 10-bit for serious grading?

More levels improve precision, but there is no universal rule that 10 bits is sufficient. ARRI LogC4, for example, specifies a 12-bit minimum. Under identical encoding, 10 bits normally gives smaller steps than 8, yet noise, compression and missing detail remain. Repacking an 8-bit source into 10 bits does not recover lost precision.

NEXT CHECK

Check the recording specification and a gradient after your actual processing, not just a codec label.

LIMIT OF THE CONCLUSION

Do not declare every 10-bit file suitable for every log or HDR workflow.

06
Fundamentals

What matters more: 10-bit or 4:4:4?

It depends on the operation. Bit depth usually matters more for tonal gradients, log/HDR and aggressive grading; spatial chroma detail matters more for chroma keying, fine coloured text and compositing. 10-bit 4:2:0 and 8-bit 4:4:4 address different limits.

NEXT CHECK

Test a smooth gradient and fine coloured edges separately through the intended processing.

LIMIT OF THE CONCLUSION

4:4:4 does not mean uncompressed; 10 bits does not restore absent chroma samples.

07
Fundamentals

Is YCbCr a colour space like Rec.709?

No. Y′CbCr is a way of representing nonlinear RGB through luma-like and colour-difference components. Primaries, transfer, matrix coefficients and range are still needed to recover colour meaning. A YCbCr label alone does not specify the gamut.

NEXT CHECK

Check color_space, color_primaries, color_transfer, color_range and pix_fmt in the stream report.

LIMIT OF THE CONCLUSION

In ffprobe, color_space normally identifies the matrix, not a complete RGB space.

08
DaVinci Resolve

What should I choose: CST, RCM or ACES?

CST is useful when you want explicit local transforms in the node tree. RCM is convenient for Resolve-centric project-level management. ACES is useful as a standardised cross-application architecture. Choose based on the project pipeline rather than assuming one is always 'better'.

NEXT CHECK

For one test clip, label input, working representation, output and the owner of each technical stage.

LIMIT OF THE CONCLUSION

Matching target names do not guarantee identical rendering in CST, RCM and ACES.

09
DaVinci Resolve

Is DaVinci Wide Gamut better than ACES?

These are different levels of description. DWG is a working RGB basis; Intermediate is its common encoding partner. ACES is a broader system with several representations and output transforms. Compare configured workflows for interchange, tool behaviour and approved output, rather than declaring one universally nicer or more correct.

NEXT CHECK

Fix versions, inputs and output transforms in the two workflows being compared.

LIMIT OF THE CONCLUSION

Do not compare pre-render values in one workflow with finished output in another.

10
DaVinci Resolve

Where should Input and Output CSTs go?

In a manual scene-referred chain, an Input CST usually normalises camera source into the working space before the main grade, while the Output CST/DRT follows scene-referred creative work. Display-specific trims may intentionally occur after the output transform. Know the state of each node rather than memorising a position as dogma.

NEXT CHECK

Bypass the creative look and map existing input and output operations.

LIMIT OF THE CONCLUSION

Do not add two supposedly mandatory CSTs without checking project settings.

11
DaVinci Resolve

Why does the image become overly contrasty after a LUT/CST?

A duplicated technical transform is a hypothesis, not a diagnosis from appearance. Project management, CSTs, LUTs or viewing settings may overlap. Wrong transfer or range can look similar. On a test copy, bypass one known stage at a time and compare the same frame rather than resetting the whole chain.

NEXT CHECK

Check project input/output first, then the purpose of every LUT/CST.

LIMIT OF THE CONCLUSION

A nicer image after bypassing a LUT does not prove the remaining path is correct.

12
DaVinci Resolve

Are RAW and Log the same thing?

No. RAW describes a family of early camera representations and decoding controls; Log describes an encoding. RAW can involve nonlinear storage and partial processing, as BRAW does. A decoder can produce a log/gamut pair or another representation. RAW does not guarantee no compression, full reversibility or identical available controls.

NEXT CHECK

Check format and decoder settings: stored data, metadata controls and already baked operations.

LIMIT OF THE CONCLUSION

Do not promise recovery of a clipped channel merely because the source is RAW.

13
DaVinci Resolve

How do I match cameras with different log/gamut encodings?

First interpret each source pair correctly and bring the media into a common working state through managed input transforms or individual CSTs. Perform balance and matching after technical normalisation. Visually matching different camera encodings before normalisation is harder and less robust.

NEXT CHECK

Compare a known neutral object and lighting after correct interpretation of both clips.

LIMIT OF THE CONCLUSION

Do not expect complete automatic matching solely from a shared working space.

14
DaVinci Resolve

Why do logos and UI graphics change in a managed project?

Finished graphics have defined encoding and visual intent. Treating them as camera scene data or rendering them again can alter appearance. Check their input profile, compositing position, output target and straight/premultiplied alpha. Assigning sRGB alone does not guarantee unchanged colour after every look or output transform.

NEXT CHECK

First test a known opaque patch, then an alpha edge of the same graphic.

LIMIT OF THE CONCLUSION

Do not fix a dark edge by changing the whole transfer function before checking alpha representation.

15
HDR and delivery

PQ or HLG — which should I choose for HDR?

PQ is an absolute display-luminance encoding commonly used for mastered/on-demand HDR. HLG is a relative broadcast-oriented system with a system gamma and suits some live/broadcast chains. The delivery specification should decide; one cannot be replaced by the other with a simple tag change.

NEXT CHECK

Confirm required transfer, primaries, range, metadata and validation conditions with the recipient.

LIMIT OF THE CONCLUSION

The words streaming and broadcast do not replace an actual delivery specification.

16
HDR and delivery

Why does 203 nits appear so often in HDR?

203 cd/m² is a nominal HDR Reference White production anchor under the ITU conditions, not a universal ceiling. A neutral 75% HLG signal is about that luminance on a 1000 cd/m² reference display at system gamma 1.2 with the adopted black-level model. Do not assume the equality under different display conditions. Highlights and objects have their own creative purposes.

NEXT CHECK

Read the conditions attached to the reference value and separate graphics white from highlight peak.

LIMIT OF THE CONCLUSION

Do not set every white object to 203 cd/m² or treat 75% HLG as an absolute PQ scale.

17
HDR and delivery

What happens to a 1000-nit master on a 600-nit TV?

A display or player may map the image to its capabilities. Algorithm, settings, metadata and actual content affect the result; identical appearance across TVs is not guaranteed. Mastering-display peak and maximum content light are distinct. Validate the approved target and representative viewing paths rather than blindly changing a master for one screen.

NEXT CHECK

Compare mastering requirements, content metadata and the TV's viewing mode.

LIMIT OF THE CONCLUSION

A bright screenshot tells neither physical display peak nor the file's MaxCLL.

18
HDR and delivery

Does PQ always mean a 10,000-nit master?

No. 10,000 cd/m² is the mathematical design ceiling of ST 2084. A real master may use a 600-, 1000-, 4000-nit or other approved peak. PQ code values retain absolute luminance meaning within the system, but the mastering display need not reach the ceiling.

NEXT CHECK

Record function maximum, mastering target and content-analysis results separately.

LIMIT OF THE CONCLUSION

Unused PQ range above a master's peak does not mean PQ was encoded incorrectly.

19
HDR and delivery

Can I make HDR by simply changing Gamma 2.4 to PQ?

No. That only re-encodes or reinterprets the signal relationship and does not automatically create a new scene/display rendering. A proper HDR trim/master requires decisions about reference white, highlight allocation, colour volume, tone/gamut mapping and monitoring target.

NEXT CHECK

Establish whether pre-SDR-render sources remain available or only a finished SDR master.

LIMIT OF THE CONCLUSION

Changing a Gamma field does not guarantee new dynamic range or recovered highlights.

20
Troubleshooting

Why did black become grey or everything become too dark?

The first suspect is a full/video range mismatch or incorrect data-level interpretation. Also check transfer assumptions and the player path. A range error changes code-value mapping to black/white and can look like washed or crushed blacks without any creative grade change.

NEXT CHECK

For 10-bit narrow Y′, inspect interpretation of 64 and 940; compare explicit Full only on a test copy.

LIMIT OF THE CONCLUSION

Grey-looking black does not prove a range mismatch without controlled evidence.

21
Troubleshooting

Why did hues shift strangely after decoding?

Check the Y′CbCr matrix and primary interpretation, as well as the transfer and preceding processing. Test matrix errors on coloured samples: equal R′=G′=B′ can remain neutral under different NCL weights. Locate the first mismatch before trying to fix it with Hue or Saturation.

NEXT CHECK

Compare coloured samples with explicitly selected matrices on the same recording.

LIMIT OF THE CONCLUSION

A normal grey ramp does not rule out a colour-difference matrix error.

22
Troubleshooting

Why does an export look different in a browser, player and Resolve?

Different applications can use different colour-management/display paths, interpret tags differently and output through different OS APIs. Compare the master on a controlled reference path, then test consumer playback separately. A screenshot from one browser is not a reference measurement of the master signal.

NEXT CHECK

Keep one file and timecode; record app, version, OS, display and HDR mode.

LIMIT OF THE CONCLUSION

A matching re-import is useful but does not certify the whole master.

23
Troubleshooting

Do pixel values change when colour tags change?

Usually not: metadata describes how values should be interpreted, while a colour transform mathematically changes the values. A player can nevertheless display the same bytes differently after seeing different tags. Retagging and transforming/transcoding are different operations.

NEXT CHECK

Compare metadata reports and a controlled decoded frame before/after under equal interpretation.

LIMIT OF THE CONCLUSION

A whole-file hash changes with metadata and does not prove pixel conversion.

24
Troubleshooting

Are scopes more important than the monitor?

They answer different questions. Scopes measure the signal representation, while a calibrated monitor shows the perceptual/rendered result. Creative colour cannot be judged from a waveform alone, just as levels/tag mismatches should not be diagnosed only by eye on an unknown display.

NEXT CHECK

Establish where scopes are calculated and what units their scale uses.

LIMIT OF THE CONCLUSION

A trace at 100% is not universal proof that an SDR/HDR master is delivery-ready.

25
Troubleshooting

Does Colour Management replace monitor calibration?

No. Management and viewing transforms mathematically prepare a signal; the physical display must match the target within its capabilities. Calibration adjusts behaviour, profiling describes it, and measurement verifies it. Neither a profile nor RCM gives a panel arbitrary gamut or luminance.

NEXT CHECK

Check target mode, a current measurement report, OS settings and the active viewing path.

LIMIT OF THE CONCLUSION

Changing a profile by eye is not measurement-based calibration.

26
Troubleshooting

Are negative RGB values or values above 1 an error?

Not necessarily. In wide-gamut floating-point scene-referred transforms, such values can be a valid intermediate state. The problem occurs when they are sent to a limited display output without appropriate gamut/tone mapping or clipping policy.

NEXT CHECK

Inspect values before/after the transform and its rules outside 0…1.

LIMIT OF THE CONCLUSION

Do not clip working values merely because ordinary display RGB is bounded.

TOPIC ILLUSTRATION

THE ESSENTIAL IDEA

Colour-science FAQ

The same visible symptom can arise at different stages. This FAQ separates an explanation, a controlled next step and the limit of the conclusion, so that a decision follows evidence rather than a similar-looking image.

  • Separate changes to a file from changes to its display.
  • Change one variable and record the result.
  • Do not treat a matching swatch as validation of the whole system.
A topic illustration, not a measurement diagram or an interface screenshot.
01

Find the first divergence

Do not start with a control that merely compensates for the appearance. Preserve the original state, take a short test segment and locate the boundary: source decoding, processing, export or another viewer?

A comparison requires matched conditions. Re-importing with the same wrong assignment can reproduce the same error. A match is useful evidence, not a correctness certificate. Inspect coloured and neutral regions, then the full shot.

What this means in practice

If changing Output Gamma hides the error, the cause is still unproven. Record what the file and viewer expected and check whether the change simply moved the problem elsewhere.

02

Establish what was recorded

A MOV or MP4 extension does not define colour. You need the stream format, precision, signalling and provenance. For camera footage, check RAW decoding, Log and gamut separately.

An unknown field calls for clarification, not a favourite default profile. ffprobe reveals stored information; it does not prove its correctness or identical interpretation by every application.

What this means in practice

Compare color_primaries, color_transfer, color_space and color_range with the camera report. In ffprobe, color_space identifies matrix coefficients, not the complete RGB-space definition.

03

Check order and ownership

Trace input, working processing and output separately. Technical operations can live in project settings rather than visible nodes. A CST node says little about preceding decoding or subsequent output.

Test suspected double processing by bypassing exactly one stage in a project copy. Disabling everything removes several possible causes at once. For a LUT, record its expected input and whether display rendering is included.

What this means in practice

In a managed project, check input assignment and project output before adding two CSTs from another example. Explicit and project-managed processing need coordination, not mechanical stacking.

04

Check component and range

Raised blacks can follow range interpretation, grading, rendering, decoding or the source itself. A range test needs known code values; a dark image alone is insufficient.

Y′ and Cb/Cr have different nominal Video scales. The Y′CbCr matrix is another variable: wrong coefficients can shift coloured regions while leaving neutral regions close to correct. A grey ramp is useful but cannot validate every colour operation.

What this means in practice

Check known 64/940 values for 10-bit Video Y′. Do not use them as universal component limits or confuse nominal levels with the full permitted code set.

05

The file and its view are separate checks

When one export differs between applications, keep the file unchanged first. Compare application colour management, system HDR mode, monitor selection and display settings. A difference does not automatically establish an export fault.

Nor can every differing viewer be dismissed without testing: the file may be incorrectly described and one path may accidentally compensate. A screenshot adds another conversion path and cannot replace measurement or an agreed monitoring setup.

What this means in practice

Compare the same short file on the same monitor in two applications and record their modes. Do not change the file, display profile and project output simultaneously.

06

Build a reproducible report

A useful report includes a test source, timeline segment, input/output settings, application version, export parameters, metadata and viewing conditions. Separate observation (“blacks are raised in A”) from hypothesis (“Video may be read as Full”).

Record one change and its result. If evidence is insufficient, retain an “undetermined” state. This is faster than accumulating compensating edits that fail on the next delivery. Use a short non-confidential sample for external review.

What this means in practice

Record: the file was unchanged; only range interpretation changed; reference codes recovered, but the coloured test still differs. That identifies a remaining variable, not complete validation.

DO. OBSERVE. EXPLAIN.

Investigate one symptom without guessing

Use a short safe clip, a project copy and one unchanged test export.

  1. 01

    State the observation

    Describe the difference, application, display and image region separately from the suspected cause.

    CHECK

    The observation contains no unverified diagnosis.

  2. 02

    Choose a control

    Find the relevant question and perform its check with one variable changed.

    CHECK

    The initial state and result of one change are recorded.

  3. 03

    Check another sample

    After a grey ramp inspect a coloured region; after one frame inspect motion.

    CHECK

    The result was not judged from one convenient swatch alone.

  4. 04

    Record the limits

    Write down what is supported, disproven and still unknown.

    CHECK

    The source is preserved and no unexplained compensation chain was accumulated.

Check your understanding

0 / 4

Tick only what you can explain yourself.

TEST THE EXPLANATION

A situation, not a trick question.

Answer first. Open the reasoning afterwards.

01A re-import matches. Is validation finished?

No. A match supports some chain hypotheses, but the same wrong interpretation can recur. A known contract and independent reference samples are still needed.

02Are raised blacks necessarily a Video/Full mismatch?

That is one hypothesis. Check known levels, processing, decoding and viewing separately instead of compensating with Lift by eye.

03Metadata changed; were the pixels transformed?

Not necessarily. Tag assignment and transformation of decoded signal are different operations. Even a whole-file hash can change because of container metadata alone.

Avoid these shortcuts

  • Do not replace missing information with familiar settings.
  • Keep the conditions with the number or definition.
COLOR / DAVINCI RESOLVE

From the model to your workflow.

Record the Resolve version, colour-management mode, input interpretation and viewing conditions. This reference helps define a check, but does not replace reviewing the full shot or validating a delivery file.

Color Management ↗Scopes ↗Color Space Transform ↗

CHECK THE FOUNDATION

Sources and model limits.

Editorial review: 1 October 2026. Links identify the definitions and formulas; exercises are independent teaching examples.

  1. [4]
    ICC · sRGB ↗

    Primaries, D65 and the piecewise transfer function.

  2. [7]
    ITU-R · BT.709-6 ↗

    Sections 1, 3, 4: primaries, OETF, coefficients and 8/10-bit digital levels.

  3. [8]
    ITU-R · BT.1886 ↗

    Annex 1: EOTF depending on black and white luminance.

  4. [9]
    ITU-R · BT.2100-3 ↗

    PQ, HLG; Table 9: 10/12-bit integer representation.

  5. [10]
    ITU-R · BT.2408-9 (03/2026) ↗

    HDR reference white and conditions for 75% HLG corresponding to about 203 cd/m².

  6. [11]
    ITU-T · H.273 (07/2024) ↗

    Independent video-identification fields; metadata is not a transform.

  7. [13]
    ACES · ACEScct ↗

    AP1 and nonlinear scene encoding with a linear toe.

  8. [14]
    ACES · Output Transforms ↗

    Target-display rendering and encoding; not merely a tag change.

  9. [15]
    Blackmagic · DWG / Intermediate v1.1 ↗

    DWG and Intermediate specify distinct properties of a working representation.

  10. [16]
    Blackmagic · Color ↗

    CST, RCM and Color tools. Menu details depend on the Resolve version.

  11. [17]
    Blackmagic · RAW ↗

    Partial demosaic and nonlinear 12-bit BRAW coding; do not generalise to all RAW.

  12. [18]
    ARRI · LogC4 specification ↗

    Precision is format-specific: LogC4 specifies a 12-bit minimum; 10 bits is not universal.

  13. [19]
    FFmpeg · ffprobe ↗

    Read stream fields without modifying the file; unknown does not prove a particular colour space.

  14. [20]
    FFmpeg · Content light metadata ↗

    MaxCLL and MaxFALL are different content-metadata fields, not measurements of the current display.

  15. [21]
    OpenColorIO · Displays & Views ↗

    Working data and viewing transforms are distinct.

  16. [22]
    W3C · CSS Color 4 ↗

    RGB conversions and browser colour definitions; document status is stated in the specification.