Ruby can command a camera to take photos, prefous, and retract autonomously or when triggered by pilot.

Capabilities

Prefocus

Shutter release

Continuous shutter release

Automatic retract at low altitude

Wait until plane level and steady before prefocus and shutter release.

Record exact times of each shutter release in recorded flight data. This information can be later used to correlate plane's position and attitude with individual photo images.

 

Supported Cameras

Canon "PowerShot" cameras capable of running "CHDK" firmware.

 

Installation / Configuration

Install CHDK firmware

 

Connect camera to Ruby

Connect a Ruby Photography Control cable between the "Panel" connector on the Ruby Expander and the USB port on the camera.
* Note that you will no longer be able to use the Control Panel.

Install latest Ruby firmware

Version 708 or higher is required. [download]

Update configuration (see below)

Configuration

You will need to obtain an updated configuration file from support@uthere.com

Here are the relevant parameters that will be updated:

View: Variables: photography: configuration:

photo_interface_type

set to "1"

handheld_map_wire_into_photo_camera_switch (optional)

Channel on handheld transmitter connected to 2- or 3-position switch.

Set to 0 if no manual operation is desired.

photo_prefocus_altitude_agl

Ruby will not prefocus until the plane is above this altitude and is relatively flat (pitch and roll < 15 deg) and steady (pitch and roll rates < 15 deg / sec).

Default: 250 ft

photo_retract_altitude_agl

Ruby will automatically retract (and shut down) the camera once below this altitude.

Default: 150 ft

Operation

Preflight

 

Manual

Camera control switch on handheld transmitter:

High	Continuous shutter release.
Middle (if 3 position switch)	If no prefocus has been performed or the prefocus has ben "invalidated", extend lens and perform prefocus. Once prefocus has been performed, no further action. Lens remains extended.
Low	Retract lens and invalidate prefocus

Actions can be triggered manually while in any Ruby mode, including "Waypoint".

 

Waypoint

 

Starting at the first waypoint and ending with the last waypoint, Ruby will simply send a shutter release command at 2.5 second intervals.
Ruby will delay each shutter release until the plane is flat and steady.

(In upcoming version, Ruby will send shutter releases at specific locations to ensure uniform photographic coverage with desired overlap regardless of airspeed and wind.)

If prefocus has not yet been performed when waypoint mode is initiated, it will be done en route to the first waypoint once plane is above photo_prefocus_altitude_agl, flat and steady.

If conditions are not met for prefocus prior to the first waypoint, Ruby will perform a prefocus at first opportunity while flying between waypoints. Ruby will not perform a shutter release until prefocus.

 

Camera retract / shutdown

Ruby cannot tell the camera to retract without shutting down the camera (It simply does not appear to be possible using CHDK).

Ruby cannot restart the camera once shut down. The user must press the power button to resart it.

Ruby will assume camera will remain shut down and will not attempt any further commands until next prelfight is performed.

 

Technical info

See Camera Photography Control: Technical : Canon CHDK