ISO CHEAT SHEET
PVME Training Division — quick reference
Full-stop ISO scale
Each step doubles or halves sensor amplification. Doubling ISO = +1 stop of light, +1 stop of noise.
50 — 100 — 200 — 400 — 800 — 1600 — 3200 — 6400 — 12,800 — 25,600 — 51,200 — 102,400
Rule of thumb: Set ISO last. Lock aperture for DOF, set shutter for motion, then push ISO only as needed to nail exposure. Modern Sony bodies are clean to ISO 6400.
Base vs native vs extended
- Native ISO range: The genuine analog amplification range. On Sony A7RV: ISO 100–32,000. Maximum image quality lives here.
- Base ISO: The lowest native ISO — best dynamic range and least noise. Sony A7RV base = ISO 100.
- Extended ISO: Software push/pull beyond native (ISO 50, 64,000+). Pulled-down ISO 50 loses one stop of highlight headroom. Pushed-up extended ISOs are just digital gain — noisier than native equivalents.
PVME starting ISO chart
| Scenario | ISO range | Mode |
|---|---|---|
| Tethered studio (strobes) | 100 | Locked manual |
| Military headshot (strobes) | 100 | Locked manual |
| Outdoor military formation, sunny | 100 – 200 | Locked manual |
| Outdoor formation, overcast | 400 – 800 | Locked manual |
| Indoor armory / hangar | 1600 – 3200 | Auto with 6400 ceiling |
| Wedding ceremony — daylight venue | 400 – 800 | Auto with floor 1/250 |
| Wedding ceremony — dim chapel | 1600 – 3200 | Auto with 6400 ceiling |
| Wedding reception (mixed light) | 3200 – 6400 | Auto with 12,800 ceiling |
| Reception with bounce flash | 800 – 1600 | Locked |
| Real estate interior (ambient + tripod) | 100 | Locked manual |
| Real estate twilight exterior | 100 – 200 | Locked manual |
| Engagement golden hour | 100 – 400 | Auto floor 1/500 |
Dual-gain (dual-conversion-gain) thresholds
Modern sensors flip to a second amplifier at a specific ISO, dropping read noise dramatically. Below the threshold = max dynamic range. Above = cleaner shadows in low light. Set Auto-ISO to skip the dirty middle ground.
| Camera | Low gain | High gain kicks in |
|---|---|---|
| Sony A7RV | ISO 100 | ISO 320 |
| Sony A7 IV | ISO 100 | ISO 800 |
| Sony A1 / A9 III | ISO 100 | ISO 500 |
| Canon R5 | ISO 100 | ISO 400 |
| Nikon Z8 / Z9 | ISO 64 | ISO 500 |
Practical use: If a scene wants ISO 250, push it to ISO 320 instead — same exposure, cleaner shadows on the A7RV.
Noise vs detail tradeoff
- ISO 100 – 400: Reference quality. Full dynamic range, deepest blacks, clean color.
- ISO 800 – 1600: Indistinguishable from base in print, slight shadow grain.
- ISO 3200 – 6400: Usable for delivery; expect mild luminance noise. DeNoise AI recommended.
- ISO 12,800: Working ISO for emergency. Color noise appears. Always run noise reduction.
- ISO 25,600+: Only when the shot otherwise doesn't exist. Convert to black and white if color breaks down.
5 common ISO mistakes
- Leaving Auto-ISO on for tethered studio — strobes will read as underexposure and ISO will spike. Lock to 100.
- Auto-ISO with no minimum shutter — body will pick 1/30 in dim light and blur subjects. Set floor.
- Cranking ISO before opening aperture — wasted noise. Open up first, then push ISO.
- Forgetting ISO 50 loses highlight headroom — never use extended low ISO on white wedding gowns.
- Running ISO 320 instead of 250 without knowing why — now you do (dual-gain).