Why this matters

Good exposure is the foundation of image quality. Too little light forces the camera to add electronic gain (noise); too much light blows out highlights and reduces contrast. Use the controls below to balance lighting, shutter, iris and digital processing so the picture looks natural on every output.

Environment Settings

• Lighting: Add more light where possible; never film directly into fixtures to avoid glare and false focus issues (Doc 3).
• Zoom: Avoid full zoom—lens extension reduces light reaching the sensor and makes focusing harder (Doc 3).
• Placement: Mount on a stable, vibration-free platform and position as close to the subject as practical (Doc 3).

1 – Pick the right Exposure Mode

OSD menu: CAMERA ▶ EXPOSURE ▶ Mode
Web GUI: VIDEO tab ▶ Camera Settings ▶ Exposure Mode

• AUTO – The camera opens the iris fully and continually adjusts shutter and gain. Best for rooms with windows or moving light effects.
• AAE (Aperture Automatic Exposure) – You lock the iris; the camera chooses shutter and gain. Ideal for studios or fixed lighting.
• SAE (Shutter Automatic Exposure) – You lock the shutter time; the camera adjusts iris and gain. Use when you must freeze motion or meet anti‑flicker rates.
• MANUAL – You set iris, shutter and gain yourself. Maximum control, but requires skill.

Dynamic vs Fixed lighting (from Doc 3)

• Dynamic light (spaces with windows): leave the camera in AUTO, or use AAE/SAE only if you can monitor continuously.
• Fixed light (studios): switch to AAE, close the iris slightly and keep exposure steady for sharper focus and less gain.

2 – Set the Iris for depth‑of‑field

The iris is the adjustable opening inside the camera’s lens—much like the pupil in your eye. By widening or narrowing this opening (expressed as f‑numbers such as f/1.8 or f/4.0), the iris controls how much light reaches the sensor:

• Wide iris (small f‑number): lets in more light, brightens the image, but reduces depth‑of‑field.

• Narrow iris (large f‑number): lets in less light, darkens the image, but increases depth‑of‑field and overall sharpness.

Depth of field is the range in front of the camera that appears acceptably sharp, from the nearest point in focus to the farthest. Changing the iris is one of the three core ways—alongside shutter speed and gain—to adjust exposure.

The higher the F number, the 

In AAE mode close the iris to F3.4 – F4.0. A smaller aperture

• gives a deeper depth‑of‑field so foreground and background stay sharp,
• reduces lens aberrations for a crisper image,
• but needs more light or gain.

3 – Choose a Shutter that fits the frame‑rate

See Objective 1 for safe shutter limits. Within that range:

• Use the 180‑degree shutter (½ frame) for natural blur: 1/100 s at 50 fps or 1/120 s at 60 fps.
• Slow shutters (1/50 s, 1/30 s) brighten dark halls but smear motion.
• Fast shutters (1/250 s – 1/1000 s) freeze sports but darken the image; add light or gain.

4 – Keep electronic Gain under control

OSD: EXPOSURE ▶ G.Limit – sets the ceiling for automatic gain.
A reasonable range is 6 – 12 dB; higher values brighten shadows but inject noise.

5 – Improve contrast with Dynamic Range Compression (DRC)

OSD: EXPOSURE ▶ DRC
DRC compresses extreme highlights and lifts shadows:

• Level Low reveals shadow detail without greying the picture.
• Higher levels can flatten contrast; increase only until faces are readable.

6 – Handle back‑light with BLC

If the speaker stands in front of a bright window, enable Back‑Light Compensation:

GUI: VIDEO tab ▶ Camera Settings ▶ BLC

• BLC is available only in AUTO exposure mode.
• Toggle BLC on the remote with BLC ON/OFF for quick A/B comparison.

7 – Synchronise shutter and mains frequency (Anti‑Flicker)

Within any exposure mode except MANUAL and SAE you can simply set Flicker to 50 Hz or 60 Hz and let the camera pick compatible shutter speeds. If you must use a manual shutter:

• 50 Hz lighting ➝ lock shutter to 1/100 s.
• 60 Hz lighting ➝ lock shutter to 1/60 s.

Quick checklist

• Start in AAE mode, iris = F3.4 – F4.0.
• Set 180‑degree shutter (1/100 s or 1/120 s) and Flicker = 50/60 Hz.
• Raise G.Limit only if picture is still dark.
• Add Low DRC; turn on BLC for windows behind the subject.

Digital Image Processing Details

• DRC (Dynamic Range Compression): Compresses extremes of brightness and darkness.
  MENU ▶ CAMERA ▶ EXPOSURE ▶ DRC
  
• Gain Limit (G.Limit): Caps automatic gain to avoid noise (6–12 dB recommended).
  MENU ▶ CAMERA ▶ EXPOSURE ▶ G.Limit
• Brightness, Contrast, Gamma, EV: Digital controls adjust overall brightness, contrast scale, sensor response and exposure compensation.
  MENU ▶ CAMERA ▶ EXPOSURE ▶ Brightness / Contrast / Gamma / EV

Back-Light Compensation (BLC) Details

• OSD Menu: MENU ▶ CAMERA ▶ EXPOSURE ▶ BLC
  
• Web GUI: VIDEO tab ▶ Camera Settings ▶ BLC
  
• IR remote: Press BLC ON/OFF for quick A/B comparison
  
• Note: BLC, DRC & G.Limit are visible only on CM40/CM7x HDMI/SDI outputs and the USB output of CM41/CM44 (Doc 7).