This probably doesn't work, use at your own risk, etc.

basic usage: (lytro-dl::download-pictures)

By default, copies files to ~/lytro/<serial>/sha1-.../<*> where serial is the camera serial number, sha1-... is the sha1 ID of the file from the file listing in the camera protocol. ~/lytro/ can be changed by specifying :DIR option to DOWNLOAD-PICTURES.

Each directory contains a set of files like

100-0004.128  100-0004.jpg  100-0004.raw  100-0004.stk  100-0004.txt  metadata

metadata is a s-expression containing some metatdata from the camera. Most useful fields are probably :rotation, :picture-date, and :last-lambda.

Other files are directly as sent by camera, ###-####.txt is json metadata containing a bunch of camera and picture settings. ###-####.raw is the raw image data, with format specified in json file (something like 3280x3280 big-endian 12bit/pixel (actual values from 168-4095), with "r,gr:gb,b" bayer filter. Lenslet array orientation/offset is also specified in the json data. ###-####.jpg is a jpeg compressed version of the raw, which loses most of the lightfield data due to compression but can provide a quick preview. ###-####.128 is thumbnail as 128x128 4:2:2 yuy2. ###-###.stk is a binary file containing a few jpg files with 320x320 images at various focus settings. See http://optics.miloush.net/lytro/TheProtocols.Commands.aspx under "load picture" for details.

If it starts getting PIPE or TIMEOUT errors, might help to run (lytro-dl::%reset-camera) to clear/halt/reset the USB endpoint. It if gets permission errors, may need to add /etc/udev/rules.d/51-lytro.rules containing

SUBSYSTEM=="usb", ATTR{idVendor}=="24cf", ATTR{idProduct}=="00a1", MODE="0777"

to tell udev to make the device readable by default, then disconnect/reconnect the usb.