Both a 24.1MP APS-C CMOS sensor and DIGIC 8 image processor are used to deliver high sensitivity and fast camera performance to suit both stills and video applications. A flexible native ISO 100-25600 range suits working in a variety of lighting conditions, and the processing capabilities minimize noise for notable clarity. The processor also enables up to 5 fps continuous shooting as well as UHD 4K video recording and a 4K time-lapse movie mode.

In addition to stills recording, the SL3 also supports UHD 4K24p video recording, as well as Full HD and HD recording. Video recording is benefitted by the inclusion of Dual Pixel CMOS AF and the Movie Servo AF focusing functions, as well as the touchscreen design of the LCD monitor for intuitive control. Movie Digital IS also helps to steady recordings by minimizing the appearance of camera shake across five axes for smoother footage. Additionally, an external microphone jack is incorporated in the body design for greater control over your recorded sound.

Employing the video capabilities, a dedicated Time-Lapse Movie mode can also be used to creatively depict subjects over a longer span of time. Interval settings between 1 second and 60 minutes are available for between 2 and 3600 consecutive frames. These individual frames can then be automatically compiled into a 4K or Full HD video file for seamless playback.

Benefitting stills shooting with the optical viewfinder, a 9-point phase-detection autofocus system provides quick and precise focusing in difficult lighting conditions. The center point is also a cross-type for enhanced accuracy and speed.

When recording video or shooting in live view, a Dual Pixel CMOS AF system is employed that offers smooth and fast focusing performance in a similar manner to how a camcorder acquires focus. This system integrates two separate photodiodes within each pixel to provide a broad and dense network of phase-detection gathering elements across a majority of the image sensor to reduce focus hunting for faster, more direct control of focus placement. When working with still imagery, this focusing system works to acquire focus quickly and accurately, making it ideally suited to shooting and tracking moving subjects so that critical focus is attained with each shot. Eye Detection AF can also be employed to prioritize focus on a recognized subject's eye. When shooting video, a Movie Servo AF mode offers smooth and natural focusing when changing from different subjects or different distances within the scene, as well as the ability to specify tracking sensitivity, AF speed, and Face Tracking priority. Benefited by the Touch AF system, rack focus is possible simply by touching elements within the scene on the touchscreen in order to change focus in an intuitive manner. Subject tracking in movies is also heightened due to the Dual Pixel CMOS AF system's ability to recognize subjects and maintain focus when working within changing or cluttered scenery.