Tips & Accuracy

01 Tracking accuracy

01

Border calibration

Match border to viewing distance

Border width isn't a fixed value — it scales with your TV size and how far you sit from it. Start at 8px for a 55" screen at 2.5m. If the camera loses tracking when pointing at edges, increase by 2px until stable. Over-wide borders clip into gameplay area on some titles.

02

Lighting

Control ambient light

The Sinden camera tracks white against dark. Bright overhead lights or windows behind the screen reduce contrast on the border. Draw blinds, dim ceiling lights, and avoid bias lighting that wraps around the screen edge. Recalibrate any time your room lighting changes significantly.

03

Exposure

Tune camera exposure

In the Sinden app, the camera preview shows what the gun sees. If the border looks grey rather than pure white, increase camera exposure. If the full screen blooms white, decrease it. Aim for a crisp, bright rectangle of white against a clearly darker surround.

04

Display mode

Use game mode on your TV

Enable Game Mode on your display to cut processing lag to its minimum — typically 5–15ms vs 80–120ms in standard modes. Even with perfect border tracking, a slow panel adds perceived inaccuracy. Check rtings.com for your TV's measured input lag in game mode.

05

Resolution

Run at native resolution

Scaling or letterboxing shifts the effective screen area, which can cause border detection to map incorrectly to game coordinates. Run MAME and emulators at your display's native resolution, and set the game to fill the full screen without additional black bars where possible.

06

Physical

Hold position and wrist, not arm

Accuracy improves when you lead with wrist micro-adjustments rather than full arm swings. Lock your elbow slightly, keep the gun arm at a consistent height, and use wrist rotation to track moving targets. Full arm movement causes overshoot on fast targets.

02 Dual gun setup

Two-player Sinden configuration

Requirements

Two Sinden guns (any mix of standard/recoil)
Two separate USB ports — avoid USB hubs if possible
Two instances of Sinden app running simultaneously
Each app assigned to its own gun device
MAME: lightgun_index 1 and 2 mapped separately
Both guns need clear view of the full border

MAME two-player input mapping

P1 Gun X → Mouse 1 X Axis
P1 Gun Y → Mouse 1 Y Axis
P1 Trigger → Mouse 1 Left
P2 Gun X → Mouse 2 X Axis
P2 Gun Y → Mouse 2 Y Axis
P2 Trigger → Mouse 2 Left

03 Offscreen reload

Offscreen reload mapping

Many arcade lightgun games require pointing off-screen to reload. In MAME, enable offscreen_reload 1 in mame.ini. The Sinden app also has a built-in offscreen reload toggle that sends a right-click when the gun points outside the tracked border area.

        # mame.ini — recommended lightgun settings

        lightgun           1

        lightgun_device    mouse

        offscreen_reload   1

        mouse              1

        restrict_vertical  0

        # Sinden app — offscreen reload

        Enable: Offscreen Reload → Right click

        Threshold: 2–4% outside border edge

For Time Crisis-style pedal mechanics in MAME, map the pedal input to a keyboard key and use a foot switch, or remap it to right mouse button if the game doesn't use offscreen reload.

04 Troubleshooting

Common issues & fixes

Cursor drifts to one corner

Border not fully visible to camera. Check for bezel overlap, HUD elements covering border, or a screen edge cut off by overscan. Disable overscan in TV settings.

Tracking fine in centre, poor at edges

Increase border width by 2–4px. The camera needs a consistent border area to anchor position at extreme angles. Also check camera exposure isn't clipping the far edge.

Erratic tracking in bright room

Ambient light is washing out the border contrast. Dim the room, close blinds, or increase the Sinden border brightness setting. Avoid direct light sources near the screen.

Gun not recognised in MAME

Ensure mouse 1 and lightgun 1 are set in mame.ini. Re-map inputs via Tab → Input (this game) after launching. Confirm both the HID and Camera devices appear in Device Manager.

Recoil fires on wrong button

Open Sinden app → Recoil config. Re-assign the trigger button. Some games send recoil on a different input — match the Sinden recoil trigger to whichever button fires in-game.

DuckStation — shots registering off-target

Recalibrate the DuckStation lightgun offset in Controller Settings. Ensure the game resolution matches your display resolution. Overscan compensation in DuckStation can shift tracking coordinates.

Second gun not detected in MAME

MAME must see two separate mouse devices. Both Sinden apps must be running. Use mouse_index in mame.ini to assign each physical gun to Player 1 and Player 2 inputs explicitly.