###Installing and using CHDK###

*There is lots of information at the "CHDK for Dummies" site: http://chdk.wikia.com/wiki/CHDK_for_Dummies
*A CHDK FAQ is here: http://chdk.wikia.com/wiki/FAQ

Follow these steps to "reprogram" a pair of SD memory cards so that they load temporary firmware to your cameras when turned on.  This firmware provides several useful enhancements including the ability to trigger two cameras simultaneously every 5-10 seconds via the USB port.

The "CHDK" or Canon Hack Development Kit must be installed on the camera's SD card.  It loads when the camera is turned on, and does not change the camera permanently.

###Choosing an SD card###

* 4GB cards are preferred because larger cards require partitioning in order to run CHDK. 4GB cards $5-10 online or a little more at a local store.
* cards must be "SDHC"

###Installing CHDK on the SD cards###

* The firmware version on the Kickstarter A495 cameras should be "100F", so the matching CHDK  file **a495-100f-1.0.0-1820-full_BETA.zip** is available at http://mighty-hoernsche.de/ (mirror)

###Installing using a PC###
*Follow the instructions here: http://chdk.wikia.com/wiki/CHDK_For_Newbies_-_How_To_Install
*This requires using the program called CardTricks: http://chdk.wikia.com/wiki/CardTricks

###Installing using a Mac:###
I had to run this command in the terminal on the files in the SD card to make them executable (on a mac):

    cd /Volumes/CANON_DC
    xattr -d com.apple.quarantine DISKBOOT.BIN PS.FI2

as outlined here: http://chdk.wikia.com/wiki/FAQ/Mac#Still_Having_Trouble.3F

* (add videos?)

###Basic settings to start with###

*Enable Remote*
To allow remote shutter release via the USB port, you must enable remote operation. In the CHDK Main Menu select Miscellaneous Stuff/Remote Parameters/Enable Remote. 

*Synchronous Shutter Release*
To precisely synchronize the shutter releases of two cameras connected to a timer, you must enable synchronous remote in CHDK. In the CHDK menu, under <strong>Miscellaneous Stuff/Remote Parameters</strong>, turn on <strong>Enable Remote</strong>, <strong>Enable Synchable Remote</strong>, and <strong>Enable Synch</strong>.

With this setting, CHDK uses the first signal from the timer to get ready to take the photo (focus, exposure, any other auto stuff) and then takes the photo on the second signal. 

###Some options available when CHDK is installed###

*Shutter Priority* -- The Canon A495 does not have this option, but CHDK adds it.  It allows the camera to set the exposure automatically while keeping the shutter speed high (thus reducing blur).  On sunny days, setting the shutter speed at 1/800 second is suggested (the IR camera may require more light and lower shutter speeds).  To use shutter priority in the CHDK menu, select <strong>Extra Photo Operations/Disable Overides</strong> = OFF, then <strong>Overide Shutter Speed</strong> = 1/800 (or whatever), then <strong>Value Factor</strong>=1. Generally you should deselect or turn OFF everything else on that menu page.

###Configuration using the camera's normal menu settings###

Personal preferences will vary, but these choices have worked well during mapping flights. In general, manual settings are preferred over automatic settings so each photo has similar qualities and will stitch together well.  The exception is exposure, which is a challenge to set correctly before launch.

*Manual Focus* -- the A495 can be set to focus on infinity.  The camera has to be in "Manual" mode for this option to appear (have to confirm this).  For most mapping flights, everything will be in focus if the camera is focused on infinity. Caution: when focus is in manual mode, MAKE SURE it is focused on infinity before launching.

*Daylight White Balance* -- When the camera is in "Manual" mode, select the sun icon for daylight white balance.

*Turn Image Stabilization (IS) OFF* --  There is some debate about this, but IS is designed for shaky hands, not cameras swaying on long lines. 

*Battery Saving Features* -- (must confirm with the A495)
   Turn the brightness of the LCD display way down
   Turn the autofocus light off