CR3
Canon RAW version 3
CR3 is Canon's current RAW file format, used by EOS R mirrorless and recent EOS DSLR bodies, with an optional smaller compressed version called C-RAW.
A CR3 file holds the sensor data from a Canon camera before it's processed into a finished image, plus a full-size JPEG preview and metadata. Canon introduced CR3 in 2018, replacing CR2, and it's what EOS R bodies such as the R5 Mark II, R6 Mark II, R7 and R8 write today.
CR3 offers two flavours: full RAW, and C-RAW, a compressed option that produces noticeably smaller files.
How it works
CR3 is based on the ISO base media file format, the same family as MP4 and HEIF. RAW mode stores the sensor data losslessly; C-RAW applies lossy compression that Canon designed to be hard to see in normal use, saving a large share of space. Lightroom, Capture One, Photo Mechanic and Canon's Digital Photo Professional all read CR3, though very new bodies sometimes need a software update first. See lossless compressed RAW for the trade-offs.
An example: C-RAW at an event
An event photographer shoots C-RAW plus JPEG on an EOS R6 Mark II for a long conference. The smaller files mean the card lasts the day, and the JPEGs go to the client while the C-RAW files wait for the edit.
CR3 and CloudTether
CloudTether tethers Canon cameras over USB and Wi-Fi and delivers CR3 files as they are to storage destinations such as Dropbox, Google Drive, OneDrive, S3 or an FTP server. Gallery services that take JPEGs only, such as SmugMug and ShootProof, skip RAW files, and the phone's photo library doesn't store RAW. To send only JPEGs and keep CR3 on the card, turn on JPEG only. Canon also writes in-camera star ratings into the file, which powers rated send.
CR3 versus CR2
Older Canon DSLRs write CR2. Software that reads CR2 but not CR3 needs an update, or a conversion to DNG.
Tips and common mistakes
- Update your editing software before shooting with a brand-new Canon body.
- C-RAW halves card and upload use in many cases — test it on your own work.
- Keep CR3 originals; previews inside them aren't a substitute.
See also
Put it into practice
CloudTether tethers your camera to your phone and delivers every shot to the cloud, live as you shoot — no laptop.