Mothco MCO-435 — Field Manual

02 · Specifications

One Sony sensor,
one HD-SDI connector.

2 MP 1/2.8" Sony IMX CMOS sensor, progressive HD-SDI output at 24/25/30 fps, regulated Lemo 2-pin power. Machined aluminum body — 58 × 52 × 52 mm, 365 g.

Sensor

2MP · 1/2.8"

Sony IMX CMOS, 1920 × 1080 effective pixels. HD 16:9 format, progressive scan. Internal sync.

Output

HD-SDI· 24/25/30p

Single BNC HD-SDI. The EX-SDI modes (1.0 / 2.0) exist in the menu but aren't used in the LENSO flow — always force HD-SDI for compatibility with the rest of video village.

Power

12–36v DC · Lemo 2-pin

Regulated DC, reverse-polarity protected. Pin 1 (red dot) = GND, Pin 2 = +DC. Operating range 10-50 °C, humidity 20-80 %.

03 · Installation

THREE M4 SCREWS.
CAMERA OFF.

The tap mounts to the ARRI 435 body with three M4 hex-socket screws. The whole operation happens with the camera powered down and with no power at the tap. Tighten the three screws evenly in a crosswise pattern so no side sits unevenly against the camera body.

Diagram of MCO-435 connectors: 1. HD-SDI output, 2. Lemo 2-pin power, 3. 4-way menu navigator button with center press, 4. Access to circuit for image position adjustment — Installation and body connectorsMothco · User Guide p.3

Connectors — identify each one

① HD-SDI output: BNC. Direct to monitor or to the wireless TX.
② Power: Lemo 2-pin. 12–36 V DC regulated.
③ OSD navigator: 4-way joystick with center press. Only control for the whole menu.
④ PCB access: Access to the circuit board for image position adjustment.

Image position adjustment

The sensor PCB is held by four M2 screws damped by rubber washers. Loosening or tightening crosswise pairs tilts the sensor plane to center the image inside the optical viewfinder frame.

It's a delicate adjustment — only touch it if the viewfinder center doesn't coincide with the tap center. Tighten each screw gently to avoid crushing the washer.

!

Two hard rules from the manufacturer

Beware of hot plugging. Connect monitors, TX, or accessories with everything off. Power up the tap first and the monitor second.

Beware of voltage differential. If the monitor runs off a very different power source than the tap (typical on steadicam), daisy-chain HD-SDI from tap → wireless TX → monitor. A large ground differential can trip the tap's protection or damage the circuit.

04 · Power

Lemo 2-pin.
Red dot to GND.

Regulated DC between 12 V and 36 V. Pin 1 (red-dot mark) is GND, pin 2 is +DC. The connector is polarity-protected, but don't push your luck: wire it right.

Lemo 2-pin pin-out

Pin 1 · red dot: GND
Pin 2: +DC · 12–36 V

Where it comes from

The cameras we ship carry a Lemo 2-pin to D-tap cable from the camera battery. For shoots with two village monitors hanging off the same chassis, consider a dedicated power line — keep the tap isolated from the voltage drops a TX creates when it powers up.

05 · Initial Settings

TWO MENU LINES
BEFORE THE FIRST SHOT.

Before you start rolling, confirm the menu boots with these two values. These are the only "must-do" settings — the rest can stay at factory defaults.

01

SYSTEM · frame rate and region

Open the menu (center press on the navigator) → 7. SYSTEM → FRAME RATE. Set:

1080/24 if shooting with TV SYSTEM US(NTSC) (60 Hz).
1080/25 if shooting with TV SYSTEM EU(PAL) (50 Hz).
To move from 25p to 30p, change TV SYSTEM first — the menu won't offer 30p while PAL is set.

02

EXPOSURE · manual shutter at 1/30

Open 2. EXPOSURE → SHUTTER → MANUAL → 1/30. Two reasons:

In AUTO, the shutter moves constantly to compensate for light — producing visible flicker on the monitor.
FLICKERLESS corrects for mains frequency (TV at 50 Hz in a PAL room), but not for the 435's own mirror-shutter flicker. For a clean viewfinder: always manual at 1/30.

i

When leaving the menu — SAVE, not CANCEL

Item 8. EXIT has two options. SAVE stores the settings and exits the menu; CANCEL exits without saving. Confuse the two and the next boot returns to factory defaults.

06 · OSD Menu

Eight items,
one joystick.

The physical navigator (4-way button with center press) is the only control. Up/down moves between items, left/right changes the value, press enters a submenu marked with ↵. The root menu has eight entries.

1 · LENS

Always MANUAL. The MCO-435 ships with a fixed-aperture integrated lens; the DC value is for auto-iris (doesn't apply).

2 · EXPOSURE

Brightness, shutter, sens-up, and AGC. The submenu most touched on set — see section 07.

3 · BACKLIGHT

Backlight compensation: HLC (mask blown zones), BLC (expose a defined rectangle), or HDR (CLEAR or DOL).

4 · DAY & NIGHT

Force color (DAY), b/w (NIGHT), or let the sensor decide by light (AUTO). Normal shoot: DAY, always.

5 · COLOR

White balance and color gain — see section 08.

6 · IMAGE

Sharpness, gamma, mirror/flip, D-WDR, defog, shading, privacy masks — see section 09.

7 · SYSTEM

Output (HD-SDI), frame rate, TV region (US/EU), language, cam title, RS-485 comm, factory reset — see section 10.

8 · EXIT

SAVE saves and exits. CANCEL exits without saving. Any change made in the other 7 items is lost if you hit CANCEL by mistake.

07 · Exposure

Brightness, shutter, AGC.

The four variables under the EXPOSURE submenu. In standard LENSO flow, SHUTTER is always manual at 1/30 — the rest can stay at defaults.

EXPOSURE screen: BRIGHTNESS 10, SHUTTER AUTO, AGC 7, RETURN — EXPOSURE submenuMenu → 2. EXPOSURE

Controls

BRIGHTNESS: 0-20. Up to brighten, down to darken. Default 10.
SHUTTER: MANUAL 1/30 always. AUTO generates flicker. FLICKERLESS helps with mains but not with the 435 mirror.
SENS-UP: Low-light exposure multiplier (×2, ×4…). Leave OFF unless extreme night work.
AGC: Max allowed gain. Higher = more noise. Default 7 is usually fine.

Symptom → tweak

Continuous flicker: SHUTTER to MANUAL 1/30.
Dark image: Raise BRIGHTNESS first; if that's not enough, raise AGC.
Visible noise: Lower AGC. If the shot still needs more light, open the lens aperture.
Blown background: BACKLIGHT → HLC or BLC in the root menu.

08 · Color and White Balance

AUTO or PRESET —
rarely MANUAL.

The COLOR submenu has two items: WHITE BAL and COLOR GAIN. In practice, the AC leaves it on AUTO or PRESET and touches COLOR GAIN if the village wants more or less saturation.

COLOR screen: WHITE BAL AUTO, COLOR GAIN 10, RETURN. Below AWB MANUAL screen: C-TEMP 5000K, R-GAIN 10, B-GAIN 10 — COLOR and AWB MANUAL submenusMenu → 5. COLOR

AUTO: The sensor tracks white continuously. Good for most setups under stable light.
AUTOext: Wider color-temperature range than AUTO. Useful when mixing tungsten interior with HMI exterior.
PRESET: Fixed white — locked in by pressing SET on a white reference card. Doesn't follow light changes.
MANUAL: Enters the AWB MANUAL submenu: C-TEMP (3000K, 5000K, 8000K), R-GAIN and B-GAIN (0-20). Only if the DP wants a specific look.
COLOR GAIN: 0-20. Up to saturate, down to desaturate. Default 10.

09 · Image

Sharpness, gamma, flip,
privacy masks.

The IMAGE submenu groups eight processing settings. Factory recommendation is to leave most at defaults; only MIRROR/FLIP and PRIVACY masks get touched on real shoots.

Recommended parameters

SHARPNESS: Default 4. Higher = harder image and more noise.
GAMMA: Default 0.45. Standard curve for HD-SDI.
MIRROR: Horizontal flip. OFF by default.
FLIP: Vertical flip. OFF by default. Useful if the tap mounts inverted on steadicam.

Compensation and masks

D-WDR: Compensates dark areas in high-contrast scenes. Leave on AUTO.
DEFOG: Improves visibility through haze. AUTO, MANUAL, or OFF.
SHADING: Compensates corner fall-off.
PRIVACY: Up to 16 rectangular masks (programmable size, color, position, transparency). Useful to cover a logo or a serial number in the background.

10 · System

Output, frame rate, region.

The SYSTEM submenu controls output format and global preferences. Two things to always check; the rest is optional.

MCO-435 SYSTEM and OUTPUT screens: OUTPUT HD-SDI, FRAME RATE 1080 30, TV SYSTEM US(NTSC), LANGUAGE ENG, CAM TITLE OFF, FACTORY RESET ON. Below OUTPUT submenu: SDI OUTPUT HD-SDI, ANALOG MODE THD — SYSTEM and OUTPUT submenusMenu → 7. SYSTEM

Required

SDI OUTPUT: Always HD-SDI. The EX-SDI 1.0/2.0 and OFF options aren't used in LENSO flow.
ANALOG MODE: Don't switch to ANALOG. Leave it as it comes from factory (THD).
FRAME RATE: 1080 24p, 25p, 30p, 60p, 50p; 720 60p or 30p. For 25p, set TV SYSTEM to PAL first.
TV SYSTEM: US(NTSC) for 60 Hz regions, EU(PAL) for 50 Hz.

Optional

LANGUAGE: English, Korean, Japanese, Chinese (simplified and traditional), German.
CAM TITLE: Up to 8 alphanumeric characters overlaid on the image. Position OFF / RIGHT UP / LEFT DOWN.
COMM: Camera ID and RS-485 speed (default ID:1, 9600 BPS). Only if a control board is present.
FACTORY RESET: Returns everything to factory. Afterwards redo the two initial settings.

11 · Troubleshooting

Fast on-set triage.

The most common symptoms and the shortest fix for each. Power, shutter, and output cover 90 % of the calls.

Symptom	Probable cause	Fix
No signal on the monitor	BNC not seated, or a "non-SDI" cable (an analog-only PAL/NTSC cable).	Reseat the BNC. Try a short SDI reference cable. An analog PAL/NTSC cable will fail even at short SDI distances.
Flicker in the image	SHUTTER on `AUTO` or `FLICKERLESS`.	Menu → 2. EXPOSURE → SHUTTER → `MANUAL` → `1/30`.
Image off-center in the viewfinder	Mechanical alignment of the sensor against the optical axis.	Open the PCB access (screw ③) and tweak the four M2 screws in cross pattern, see section 03. Don't do it on set — better bring it to the warehouse.
Random image dropouts	Voltage drop below 12 V or ground differential with the monitor.	Swap the camera battery, verify the monitor is daisy-chained through the wireless TX (not direct to the tap).
Over-saturated or flat colors	COLOR GAIN out of range or AWB on the wrong mode.	Menu → 5. COLOR → WHITE BAL `AUTO`, COLOR GAIN `10`. If the DP wants a look, use AWB MANUAL with fixed C-TEMP.
Image inverted	FLIP and/or MIRROR active — typical when inheriting settings from an earlier steadicam build.	Menu → 6. IMAGE → MIRROR `OFF`, FLIP `OFF`.
Settings lost on power-off	Exited the menu with `CANCEL` instead of `SAVE`.	Back to the menu, redo the changes, exit via 8. EXIT → SAVE.
Artifacts after hot-plugging an accessory	Hot-plug with the tap powered.	Cut tap power, connect the accessory, power on again. Protection should have caught it — but it's not free.
Nothing works after too many menu changes	Menu in inconsistent state.	Menu → 7. SYSTEM → `FACTORY RESET` → ON. Then redo the two initial settings (SYSTEM and SHUTTER).