Jun 2017

You can launch gphoto2 from the command line, just enter

  gphoto2

Now because you didn't specify any parameters, gphoto2 will show you a list of available commands.

Usage: gphoto2 [-?valLnPTDR] [-?|--help] [--usage] [--debug] [--debug-logfile=FILENAME] [--quiet]
        [--hook-script=FILENAME] [--stdout] [--stdout-size] [--auto-detect] [--show-exif=STRING]
        [--show-info=STRING] [--summary] [--manual] [--about] [--storage-info] [--shell]
        [-v|--version] [--list-cameras] [--list-ports] [-a|--abilities] [--port=FILENAME]
        [--speed=SPEED] [--camera=MODEL] [--usbid=USBIDs] [--config] [--list-config]
        [--list-all-config] [--get-config=STRING] [--set-config=STRING] [--set-config-index=STRING]
        [--set-config-value=STRING] [--reset] [--keep] [--no-keep] [--wait-event=COUNT]
        [--wait-event-and-download=COUNT] [--capture-preview] [-B|--bulb=SECONDS] [-F|--frames=COUNT]
        [-I|--interval=SECONDS] [--reset-interval] [--capture-image] [--trigger-capture]
        [--capture-image-and-download] [--capture-movie=COUNT or SECONDS] [--capture-sound]
        [--capture-tethered=COUNT] [--trigger-capture] [-l|--list-folders] [-L|--list-files]
        [-m|--mkdir=DIRNAME] [-r|--rmdir=DIRNAME] [-n|--num-files] [-p|--get-file=RANGE]
        [-P|--get-all-files] [-t|--get-thumbnail=RANGE] [-T|--get-all-thumbnails] [--get-metadata=RANGE]
        [--get-all-metadata] [--upload-metadata=STRING] [--get-raw-data=RANGE] [--get-all-raw-data]
        [--get-audio-data=RANGE] [--get-all-audio-data] [-d|--delete-file=RANGE] [-D|--delete-all-files]
        [-u|--upload-file=FILENAME] [--filename=FILENAME_PATTERN] [-f|--folder=FOLDER] [-R|--recurse]
        [--no-recurse] [--new] [--force-overwrite] [--skip-existing]

Or you can use the following for a better description of each command:

  gphoto2 --help

This will give the following output:

Usage: gphoto2 [OPTION...]

Common options
  -?, --help                                 Print complete help message on program usage
      --usage                                Print short message on program usage
      --debug                                Turn on debugging
      --debug-logfile=FILENAME               Name of file to write debug info to
      --quiet                                Quiet output (default=verbose)
      --hook-script=FILENAME                 Hook script to call after downloads, captures, etc.

Miscellaneous options (unsorted)
      --stdout                               Send file to stdout
      --stdout-size                          Print filesize before data
      --auto-detect                          List auto-detected cameras
      --show-exif=STRING                     Show EXIF information
      --show-info=STRING                     Show info
      --summary                              Show summary
      --manual                               Show camera driver manual
      --about                                About the camera driver manual
      --storage-info                         Show storage information
      --shell                                gPhoto shell

Get information on software and host system (not from the camera)
  -v, --version                              Display version and exit
      --list-cameras                         List supported camera models
      --list-ports                           List supported port devices
  -a, --abilities                            Display camera/driver abilities

Specify the camera to use
      --port=FILENAME                        Specify device port
      --speed=SPEED                          Specify serial transfer speed
      --camera=MODEL                         Specify camera model
      --usbid=USBIDs                         (expert only) Override USB IDs

Camera and software configuration
      --config                               Configure
      --list-config                          List configuration tree
      --list-all-config                      Dump full configuration tree
      --get-config=STRING                    Get configuration value
      --set-config=STRING                    Set configuration value or index in choices
      --set-config-index=STRING              Set configuration value index in choices
      --set-config-value=STRING              Set configuration value
      --reset                                Reset device port

Capture an image from or on the camera
      --keep                                 Keep images on camera after capturing
      --no-keep                              Remove images from camera after capturing
      --wait-event[=COUNT]                   Wait for event(s) from camera
      --wait-event-and-download[=COUNT]      Wait for event(s) from the camera and download new images
      --capture-preview                      Capture a quick preview
  -B, --bulb=SECONDS                         Set bulb exposure time in seconds
  -F, --frames=COUNT                         Set number of frames to capture (default=infinite)
  -I, --interval=SECONDS                     Set capture interval in seconds
      --reset-interval                       Reset capture interval on signal (default=no)
      --capture-image                        Capture an image
      --trigger-capture                      Trigger capture of an image
      --capture-image-and-download           Capture an image and download it
      --capture-movie[=COUNT or SECONDS]     Capture a movie
      --capture-sound                        Capture an audio clip
      --capture-tethered[=COUNT]             Wait for shutter release on the camera and download
      --trigger-capture                      Trigger image capture

Downloading, uploading and manipulating files
  -l, --list-folders                         List folders in folder
  -L, --list-files                           List files in folder
  -m, --mkdir=DIRNAME                        Create a directory
  -r, --rmdir=DIRNAME                        Remove a directory
  -n, --num-files                            Display number of files
  -p, --get-file=RANGE                       Get files given in range
  -P, --get-all-files                        Get all files from folder
  -t, --get-thumbnail=RANGE                  Get thumbnails given in range
  -T, --get-all-thumbnails                   Get all thumbnails from folder
      --get-metadata=RANGE                   Get metadata given in range
      --get-all-metadata                     Get all metadata from folder
      --upload-metadata=STRING               Upload metadata for file
      --get-raw-data=RANGE                   Get raw data given in range
      --get-all-raw-data                     Get all raw data from folder
      --get-audio-data=RANGE                 Get audio data given in range
      --get-all-audio-data                   Get all audio data from folder
  -d, --delete-file=RANGE                    Delete files given in range
  -D, --delete-all-files                     Delete all files in folder (--no-recurse by default)
  -u, --upload-file=FILENAME                 Upload a file to camera
      --filename=FILENAME_PATTERN            Specify a filename or filename pattern
  -f, --folder=FOLDER                        Specify camera folder (default="/")
  -R, --recurse                              Recursion (default for download)
      --no-recurse                           No recursion (default for deletion)
      --new                                  Process new files only
      --force-overwrite                      Overwrite files without asking
      --skip-existing                        Skip existing files

The first thing we need to do with gphoto2 is to check that we can detect the make and model of our camera, if this part fails, then it is likely that your camera is not supported. If you have a particularly old DSLR (acutally, gphoto2 works with cameras other than DSLRs) then you might not get any support, or only limited support.

So for instance, my 12 ish year old Canon 300D is supported (yay) and here is what is supported:

  Canon EOS 300D (normal mode)	Image Capture, Liveview, Configuration	 
  Canon EOS 300D (PTP mode)	 	 

On the other hand, I would expect that any body I, or anyone else buys this year, will have to wait for some support to be added.

There is a list of supported models available at this url: http://gphoto.org/proj/libgphoto2/support.php