📖 Theory · Module 01B · Lecture 1B.4
Bit Depth — 8-bit vs 10-bit
Two cameras. Same lens. Same scene. Same S-Log3 profile. One grades beautifully. One falls apart the moment you push it. The difference is almost always bit depth.
🎬 Take 1
First — What Is a Stop?
Before bit depth makes sense, you need to understand stops. A stop is the unit camera operators use to measure light. One stop equals double or half the amount of light. Go up one stop — twice as much light reaching the sensor. Go down one stop — half as much light.
🔊
Think of it like volume on a speaker. You are not measuring decibels — you are measuring light levels in steps. Each step up doubles the brightness. Each step down halves it.
Every camera has a maximum number of stops it can capture in a single shot before detail is either crushed to black or blown to white. This maximum is called its dynamic range.
Every camera has a maximum number of stops it can capture in a single shot before detail is either crushed to black or blown to white. This maximum is called its dynamic range.
📊 Dynamic Range — Stops Per Camera Type
Each bar shows the maximum stops of light the camera can capture in a single shot
17
14
11
8
5
0
Phone
~10–12 stops total
~5–7 usable
~5–7 usable
Entry DSLR
~11–12 stops
8-bit typical
8-bit typical
Sony FX3
~13–14 clean stops
10-bit S-Log3
10-bit S-Log3
ARRI Alexa 35
~15–17 stops
Cinema benchmark
Cinema benchmark
⚠️ Sony's Fx3 official claim is 15+ stops. Independent lab tests show ~13–14 clean usable stops in real-world shooting. Still far more than any entry camera.
🏮 Real Wedding Example — Why This Matters
A wedding mandap. Bright tube lights above. Dark corners in the hall. Deep shadow under the stage. Bright window in the background. The difference between the darkest shadow and the brightest light in that room might span 14–15 stops of light.
A phone camera captures ~10–11 stops — everything outside that range either crushes to black or blows to white. The FX3 captures all 13–14 usable stops — nothing is lost.
This is why the production house uses the FX3. Not because it looks nicer on a screen straight out of camera — because it captures more of the room, in more detail, with more to work with in post.
A phone camera captures ~10–11 stops — everything outside that range either crushes to black or blows to white. The FX3 captures all 13–14 usable stops — nothing is lost.
This is why the production house uses the FX3. Not because it looks nicer on a screen straight out of camera — because it captures more of the room, in more detail, with more to work with in post.
🎬 Take 2
Now — What Is Bit Depth?
You know stops tell you how wide the camera's light range is. Bit depth tells you how many recording steps are available to cover that range. Same stops of light — but how finely are those stops divided?
🏢
Think of a staircase from the basement to the rooftop. You already know from Lecture 1B.1 — basement = shadows, every floor in between = midtones, rooftop = highlights. The FX3 captures roughly 14 floors of light — 14 stops from deepest shadow to brightest highlight.
Now — how many stairs are on each floor?
8-bit: 256 total steps across all 14 floors = roughly 18 stairs per floor. Coarse. Jumpy.
10-bit: 1,024 total steps across all 14 floors = roughly 73 stairs per floor. Four times smoother.
Same staircase. Same basement to rooftop. But 10-bit gives you four times more steps to climb — so the transitions between shadow and midtone, midtone and highlight, stay smooth and invisible.
Now — how many stairs are on each floor?
8-bit: 256 total steps across all 14 floors = roughly 18 stairs per floor. Coarse. Jumpy.
10-bit: 1,024 total steps across all 14 floors = roughly 73 stairs per floor. Four times smoother.
Same staircase. Same basement to rooftop. But 10-bit gives you four times more steps to climb — so the transitions between shadow and midtone, midtone and highlight, stay smooth and invisible.
8-bit — The Numbers
2⁸ = 256 levels per colour channel (Red, Green, Blue separately). Total colour combinations: 256 × 256 × 256 = 16.7 million colours. Sounds like a lot — until you try to grade it.
10-bit — The Numbers
2¹⁰ = 1,024 levels per colour channel. Total colour combinations: 1,024 × 1,024 × 1,024 = 1.07 billion colours. Same colour space. Same gamma. Just four times more steps between black and white.
🎬 Take 3
The Staircase — 8-bit vs 10-bit
🪜 Same 14 Stops — Different Number of Steps
Each step = one recordable brightness level. More steps = smoother transitions in your grade.
8-bit
256 STEPS TOTAL
~18 stairs per stop — gaps visible when graded hard
10-bit
1,024 STEPS TOTAL
~73 stairs per stop — transitions stay invisible under heavy grades
🎬 Take 4
What Banding Looks Like
This is the moment where 8-bit falls apart. Not immediately — it looks fine straight out of camera. The problem only appears when you grade it.
Imagine the sky behind the mandap at golden hour. A beautiful smooth gradient from deep blue at the top to warm orange near the horizon. In 8-bit that gradient has 256 steps total. When you push the exposure, add contrast, or pull shadow detail during grading — you stretch those steps apart. The smooth gradient runs out of steps. The transitions between steps become visible — called banding. You can see the stair edges as stripes across the sky.
🌅 Sky Behind The Mandap — After Grading
Same grade applied to both. Same push on exposure and contrast.
10-bit S-Log3
Smooth gradient. Grade absorbed cleanly. No visible steps. Detail preserved throughout.
Smooth gradient. Grade absorbed cleanly. No visible steps. Detail preserved throughout.
8-bit footage
Visible stripes across the sky. Grade ran out of steps. Cannot fix in post — the data was never there.
Visible stripes across the sky. Grade ran out of steps. Cannot fix in post — the data was never there.
💡 Why 10-bit Looks the Same Until You Grade
Straight out of camera — 8-bit and 10-bit footage often look completely identical. The difference is invisible on a monitor at base exposure. It only reveals itself the moment you push the grade. This is why the FX3 shoots 10-bit internally — not for how it looks before editing, but for how much it survives during editing.
🎬 Take 5
8-bit + Log = A Serious Problem
This is the critical connection. You learned in 1B.2 that Log footage compresses a wide dynamic range into the recordable zone — shadows lifted, highlights pulled down, everything squeezed to the middle. That compression means tonal values are packed very close together inside the file.
When you expand them back during grading in DaVinci — you are stretching those values apart again. With 8-bit Log — you started with only 256 steps, already compressed into a tight zone. When DaVinci stretches them back — the gaps between steps become very visible. Banding. Noise. Artefacts.
8-bit Log — What Happens
256 steps compressed into a tight Log zone. Grade stretches them back. Gaps between steps become visible banding. Pushing shadows shows noise immediately. Sky gradients stripe. Skin tones posterise. Cannot fix — the steps were never there to begin with.
10-bit Log — What Happens
1,024 steps compressed into the same tight Log zone. Grade stretches them back. Four times more steps — gaps stay invisible. Shadows lift cleanly. Sky stays smooth. Skin tones grade naturally. The FX3 records 10-bit internally in all modes for exactly this reason.
📌 The Rule
Log footage must be 10-bit. 8-bit Log is technically possible to record — but practically unusable for professional colour grading. If someone asks why the FX3 or M4 shoots 10-bit — this is the answer.
🎬 Take 6
What Your Cameras Shoot
Sony FX3
10-bit 4:2:2 internally — all modes. S-Log3 S-Gamut3.Cine is the recommended setting. 16-bit RAW available via HDMI for external recording. Sony claims 15+ stops dynamic range — real-world clean stops approximately 13–14.
✅ 10-bit
Sony M4
10-bit internal recording. Same S-Log3 S-Gamut3.Cine workflow as FX3. Handles Log footage cleanly. Same production house grading pipeline applies.
✅ 10-bit
Phone Cameras
Standard video mode = 8-bit. Usable exposure latitude is approximately 5–7 stops in real-world shooting — much less than the spec sheet suggests. Exception: iPhone 15 Pro with ProRes Log = 10-bit. But even then, the tiny sensor limits real dynamic range. Use phone footage with minimal grading only.
⚠️ 8-bit
Guest / Backup Cameras
Almost always 8-bit Rec.709. Entry DSLRs, consumer mirrorless, compact cameras — standard video mode. No Log. No 10-bit. Grade gently. Match softly to the main FX3 footage. Do not try to make it look identical.
8-bit
Quick note on 4:2:2 vs 4:2:0: The FX3 shoots 4:2:2 — this means the colour information between pixels is sampled more fully. Phone cameras shoot 4:2:0 — colour information is more compressed. Think of it as another layer of colour quality on top of bit depth. Not critical to memorise now — just know it exists and that 4:2:2 is better for grading.
⚡ Pro Tip
Grade Guest Footage Gently — Always
When you receive footage from a guest camera or backup camera that is 8-bit Rec.709 — do not try to grade it heavily. Apply minimal correction only. Pushing 8-bit footage hard will show banding in sky gradients and noise in shadows immediately.
Match it gently to the main FX3 footage — do not try to make it look identical. A soft match that sits comfortably in the edit is better than a hard grade that falls apart.
Match it gently to the main FX3 footage — do not try to make it look identical. A soft match that sits comfortably in the edit is better than a hard grade that falls apart.
✅ Checkpoint
✅ Quick Check
You apply a grade to the FX3 S-Log3 footage and the sky behind the mandap starts showing visible stripes. The FX3 is 10-bit. What is the most likely cause?
Almost certainly not a bit depth problem — the FX3 shoots 10-bit internally and 10-bit S-Log3 handled correctly should not band under a normal grade.
The most likely cause is incorrect Input Colour Space or Input Gamma settings in DaVinci. If these are set wrong, DaVinci is fighting against the footage rather than working with it — applying corrections to a signal it does not understand. The grade ends up stretching the values incorrectly and the image breaks down.
Check your input settings first. Confirm S-Gamut3.Cine and S-Log3 are set as the input — then check the XML files to make sure that is actually what was shot. Banding in correctly managed 10-bit footage is rare.
The most likely cause is incorrect Input Colour Space or Input Gamma settings in DaVinci. If these are set wrong, DaVinci is fighting against the footage rather than working with it — applying corrections to a signal it does not understand. The grade ends up stretching the values incorrectly and the image breaks down.
Check your input settings first. Confirm S-Gamut3.Cine and S-Log3 are set as the input — then check the XML files to make sure that is actually what was shot. Banding in correctly managed 10-bit footage is rare.