Index:
	01 - Introduction & Camera Specific Notes

	02 - Installation

	03 - FAQ

	04 - Links, Urls

	05 - GPL, License

	06 - uBASIC copyright notice


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01 - Introduction

Hi, 

this is the small readme to CHDK. It provides just enough info to get you rolling, for more information use the links in the bottom.


CHDK is a firmware enhancement that operates on a number of Canon Cameras. CHDK gets loaded into your camera's memory upon bootup (either manually or automatically). It provides additional functionality beyond that currently provided by the native camera firmware.

CHDK is not a permanent firmware upgrade: you decide how it is loaded (manually or automatically) and you can always easily remove it. 

Main features:

    * Save images in RAW format
    * Ability to run "Scripts" to automate the camera
    * Live histogram (RGB, blended, luminance and for each RGB channel)
    * Zebra mode (blinking highlights and shadows to show over/under exposed areas)
    * An "always on" full range Battery indicator
    * Ability to turn off automatic dark-frame subtraction
    * a higher compression movie mode, and double the maximum video file size
    * exposure times as long as 65 seconds
    * exposure times as little as 1/10,000 of a second
    * ability to use the USB port for a remote trigger input 

Additional features:

    * a depth-of-field (DOF)-calculator
    * File browser
    * Text reader
    * Calendar
    * Some fun tools and games 

Why would I want to use CHDK?

    * To get Raw file capability on cameras that don't have that ability
    * To get the ability to use scripts
    * to be able to know the battery status at all times (not just when it's about to run out of power)
    * you want or need any of the other enhancement features that CHDK provides 

What are scripts? Scripts are Lua or uBASIC language programs that give you the ability to control the operation of the camera under program control. They have been used to add or extend the native capability of the camera: more flexible intervalometers, extended-range exposure compensation, extended bracketing ability, lightning photography, etc. See the script pages for more details.


*** Build Information ***
CHDK for m10 fw:110d PID:12960
build:1.7.0-6343_BETA date:Sun, 21 Sep 2025 04:57:24 +0200

*** Camera specific notes ***
EOS M10 notes

CHDK is a hack, use at your own risk!

CHDK support for interchangeable lens cameras is incomplete.

Default ALT button is the playback button.

The half press zebra shortcut button is "UP" on the 4-way controller.

The RAW shortcut (and generic shortcut) button is the VIDEO button.

Notes

- To select a digit in a CHDK menu numeric field, press the shutter halfway

- To achieve card speeds greater than 20MB/s, card is now powered off during CHDK start.
  This may result in additional startup delay, depending on card. Reports about card issues
  are welcome in the forum: https://chdk.setepontos.com/index.php?topic=13089.0

- Video bitrate can be adjusted (CBR, VBR). Maximum possible video bitrate is approx. 41000 kbit/s

- Video time based limits are raised to 3 hours

- Clean overlay is possible for HDMI output purposes: See "Video Parameters" -> "Clear Canon overlays"
  "Rec": Canon overlay is removed upon entering shooting (aka rec) mode
  "MviRec": Canon overlay is removed when recording video
  CHDK overlay needs to be removed separately, in the "CHDK Settings" menu.
  For more info, visit https://chdk.setepontos.com/index.php?topic=13489

- This camera can switch on itself after a user-initiated delay. This feature can be used from a user-written Lua script.
  For more details and the script, see https://chdk.setepontos.com/index.php?topic=12542.msg137151#msg137151

Issues

- CHDK dark frame subtraction control only seems effective when Canon setting is on AUTO

- Exposure overrides may fail to apply when shutter is held halfway down for a while
    - this does not happen when an AF lens is attached and auto focus succeeds
    - does not happen in M mode
    - does not happen when AE is locked using the Canon controls (asterisk on the 4-way controller)

- Exposure overrides may also fail to apply when the shutter is pressed too quickly

- Av override selector in the Enhanced Photo Operations menu has garbage entries

- Low resolution HDMI modes have shortcomings and are best to be avoided:
    - Canon overlay looks coarse due to halved vertical resolution
    - CHDK overlay has an even lower resolution (just 320 pixels wide) which affects some UI elements (such as the file selector)


Tested (using 15-45 kit lens)

- Exposure overrides in (semi-)manual modes (not very extensively)
- CHDK RAW/DNG in (semi-)manual modes (Av, Tv, M, P) (not very extensively)
- PTP play/rec switch
- llibtst.lua
- setmode.lua - one failure with default 10ms delay, works with 100ms
- ubtest.bas
- hooktest.lua (Av, Tv, M, P)
- isobase.lua
- PTP live view
- Motion detection (reaction time not tested)
- USB remote - plug test
- chdkptp cam tests
- bracketing in continuous mode - Tv, ISO works, Av also seems to work

Untested

- RAW/DNG, overrides in scene/auto modes

Not implemented

- CHDK touchscreen functionality
- CHDK mirrorless camera support is not complete
    - Zoom related functionality is missing (except for focal length display)
    - Most focus related functions are not working and are untested
- Filewritetask is not currently supported

Developer notes

- [WORKED AROUND] Camera crashes with "Vector 0x37" (??) exception if spytask starts too soon (??).
    Guesses: 
        - too early use of the busyonscreen functions ?
          Worked around, using a flag from "GUISrv_StartGUISystem_FW".
          Does not help. Works if _GetLogToFile() is called prior to shooting_init() in spytask.
        - spytask calls something else too early


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02 - Installation

To install CHDK on your Canon P&S camera,  you need to know the model number and firmware version of your cameras in order to get the right version of CHDK for your camera  Details on how to determine this can be found here :

http://chdk.fandom.com/wiki/Downloads


Once you have the correct CHDK installation file for your camera,  you need to prepare and load your camera's SD card with CHDK.  The best method for doing this depends on how you intend to use your camera and the date your particular carmera was released.  Details can be found here :

http://chdk.fandom.com/wiki/Prepare_your_SD_card

Once you have correctly loaded CHDK,  you can refer to the following section for instructions on how to use CHDK.

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03 - FAQ

1. What is CHDK?

    CHDK is not just one thing! The term CHDK refers to free software currently available for many (but not all) Canon PowerShot compact digital cameras that you can load onto your camera's memory card to give your camera greatly enhanced capabilities. 

2. Am I likely to be interested in CHDK?

    The enhanced capabilities that CHDK provides are most likely to be of interest to experienced photographers - if you believe that your Canon PowerShot camera already has more features than you will ever need, you probably won't be interested in CHDK. 

3. Is CHDK safe to use?

    Yes CHDK is experimental and has risks, but with tens of thousands of happy users it can generally be considered safe. CHDK doesn't make any actual changes to your camera. If you delete the CHDK software from your memory card, or if you choose not to activate the CHDK software on the card (or remove and replace the batteries), then the camera will behave absolutely normally - nothing has been (or ever is) changed, so the warranty is not affected. 

4. How does CHDK work?

    CHDK makes use of the microprocessor that controls the camera (every digital camera contains a microprocessor) to act as a programmable computer that provides the extra capabilities. 

5. What extra capabilities does CHDK provide?

    The current set of extra capabilities fall into six categories:

        a. Enhanced ways of recording images - you can capture still pictures in RAW format (as well as JPEG), and for video images you can have increased recording time and length (1 hour or 2 GB), and a greatly increased range of compression options. 
        b. Additional data displays on the LCD screen - histogram, battery life indicator, depth of field, and many more. 
        c. Additional photographic settings that are not available on the camera by itself - longer exposure times (up to 65 seconds), faster shutter speeds (1/25,000 sec, and faster in some cases), automatic bracketing of exposure, etc. 
        d. The ability for the camera to run programs ('scripts', written in a micro-version of the BASIC language) stored on the memory card - these programs allow you to set the camera to perform a sequence of operations under the control of the program. For example, a camera can be programmed to take multiple pictures for focus bracketing, or take a picture when it detects that something in the field of view moves or changes brightness. 
        e. The ability to take a picture, or start a program on the memory card, by sending a signal into the USB port - you can use the USB cable to take a picture remotely. 
        f. The ability to do a number of other more useful (and fun) things, such as act as a mini file browser for the memory card, let you play games on the LCD screen, etc. 

6. What else should I know?

    Developers around the world are continuing to add new features to CHDK. Because the idea of using the camera's microprocessor is so flexible, various developers have made different versions of CHDK, and new features continue to be developed - for example, one version of CHDK has features assist in taking stereo photographs, and even allows two cameras to be synchronized to take pictures at the same time (with an accuracy of better than 0.1 milliseconds, providing they are the same camera model). 

The best place to find out more about CHDK is to follow the CHDK wiki  ( http://chdk.fandom.com/wiki/CHDK ) and CHDK user forum ( http://chdk.setepontos.com/ ).




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04 - URLs, Links


For more information visit the following links:

CHDK Forum :                    http://chdk.setepontos.com/index.php

CHDK Wiki:                      http://chdk.fandom.com/wiki/CHDK
CHDK Wiki FAQ:                  http://chdk.fandom.com/wiki/FAQ

CHDK Features :                 http://chdk.fandom.com/wiki/CHDK_User_Manual#Introduction
CHDK in Brief :                 http://chdk.fandom.com/wiki/CHDK_in_Brief
CHDK User Quick Start Guide :   http://chdk.fandom.com/wiki/CHDK_User_Quick_Start_Guide.pdf
CHDK User Manual :              http://chdk.fandom.com/wiki/CHDK_User_Manual
CHDK for Dummies :              http://chdk.fandom.com/wiki/CHDK_for_Dummies
CHDK Installation Guide :       http://chdk.fandom.com/wiki/File:CHDK_Installation_Guide.pdf

One Page Users Guide :          http://chdk.fandom.com/wiki/One_Page_Ultra-Quick_Users_Guide

Prepare Your SD Card :          http://chdk.fandom.com/wiki/Prepare_your_SD_card




*********************************

05 - GPL


/*
 * This file is part of CHDK.
 * Copyright (C) 2008 The CHDK Team
 * CHDK - CHDK Wiki
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA,
 * 02110-1301  USA
 */

*********************************

06 - uBASIC copyright notice

CHDK contains a modified version of Adam Dunkels uBASIC. 

The following notice applies to the original uBASIC code:

Copyright (c) 2006, Adam Dunkels
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.
3. Neither the name of the author nor the names of its contributors
   may be used to endorse or promote products derived from this software
   without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.

