Canon EOS Rebel T6i W Instruction Manual page 119

1
1 is the raw image data before it is made into 73 or other images.
1 images cannot be viewed on a computer without the use of EOS
software, such as Digital Photo Professional (p.404). However, you can
perform various adjustments on them that are impossible with other
image types such as 73. 1 is effective when you want to precisely
adjust the image yourself or shoot an important subject.
1+73
1+73 records a 1 image and a 73 image with a single shot. The
two images are saved to the card simultaneously. The two images will
be saved in the same folder with the same file numbers (file extension
.JPG for JPEG and .CR2 for RAW). 73 images can be viewed or
printed even with a computer which does not have the EOS software
installed.
RAW Image Processing Software
To display RAW images on a computer, using Digital Photo Professional

(DPP, EOS software, p.404) is recommended.
Previous DPP Ver.4.x cannot process RAW images taken with this

camera. If your computer has the previous DPP Ver.4.x, update it with
the EOS DIGITAL Solution Disk. (The previous version will be
overwritten.) Note that DPP Ver.3.x or earlier cannot process RAW
images taken with this camera.
Commercially-available software may not be able to display RAW

images taken with this camera. For compatibility information, contact the
software manufacturer.
3 Setting the Image-Recording Quality
1 image
73 image
File number
0001 . CR2
0001 . JPG
File extension
119