Published: June 2, 2017
The Canon EOS 77D (9000D) is a mid-level DSLR offering a less expensive alternative to the 80D but positioned above the Rebel T7i. It offers full HD video up to 60fps and 6 fps high-speed continuous shooting at full resolution using its 24.2 megapixel APS-C sensor. It has a DIGIC 7 image processor and provides an ISO range from 100-51,200. The dual-pixel AF uses sensor-based focusing to enable auto focus during Live View and video recording, while 45 cross-type phase detect sensors provide autofocus when using the optical viewfinder and function up to maximum apertures including f/8.
The Canon 77D has a single SD card slot and supports UHS-I cards. To compare memory card performance, 125 SD cards were tested in the camera. All cards tested support UHS-I (UHS-II cards operate in UHS-I mode in the 77D). Test results are calculated and presented in average write speed for continuous of RAW images, as well as continuous shooting for the number of images taken in 30 seconds using RAW+JPEG, RAW, and JPEG image settings. Following the results, an analysis provides additional details observed during the tests. The fastest SD cards for the 77D are recommended including suggested cards for best value in the camera.
The camera is mounted on a tripod and controlled by a remote release timer. A manual lens is used with aperture set via the lens. Focus is set manually using Live View at maximum magnification. The image subject is a detailed scene illuminated by controlled lighting. The average write speed is calculated during extended shooting with a buffer full shot condition and is calculated by dividing the total size (in bytes) of images written to the card divided by the write time (in seconds). Results are provided in megabytes per seconds (MB/s) where 1 MB = 1,048,576 bytes. Write speeds is for RAW image mode which provides the highest average write speed (RAW+JPEG and JPEG modes have lower write speeds).
Continuous shooting results show the number of images captured in 30 seconds. The 77D is tested using three image modes: RAW+JPEG, RAW, and JPEG. The JPEG mode image setting is large, high quality. The total time the shutter is activated is 30 seconds and does not include the time to clear the buffer. Continuous shooting with the 77D is limited by the memory card write speed and once the buffer reaches capacity the frame rate slows down depending on the write speed of the card. Faster memory cards allow more shots because they clear the buffer faster so the camera can shoot more shots.
The continuous shooting results depend on camera settings and the image subject. The detailed subject for this test creates large files: 33.5 MB RAW (.CRW) and 12.6 MB JPEG. Using a less detailed image subject will yield higher numbers.
The Canon 77D supports UHS-I cards including the fastest SDR104 mode which provides up to 104MB/s bus speed. The highest average write speed measured in the 77D was 81.2 MB/s. This is very close to the 81.5 MB/s maximum measured in the Canon 80D. Although several UHS-II cards were tested, they function in UHS-I mode in the 77D and offer practically the same write speed in the camera as fast UHS-I cards. UHS-II cards are faster only in devices that have the pins required to use the UHS-II interface, the Canon 77D does not. UHS-II cards will provide faster download speed when used in a UHS-II card reader. The cards can support up to 300MB/s read speed when used in UHS-II devices.
The 77D has a comparatively large buffer for a camera at its price point and the buffer size is similar to the 80D. When shooting RAW images, the camera captured up to 27 shots at full frame rate until the buffer was full when using the faster cards. Slower cards reduced this number and the slowest card could only capture 18 shots before the card speed limited shooting. The difference is due to the higher rate at which the faster cards can clear the buffer while shooting. That difference is even more apparent after after the buffer is full; the fastest card shot at 2.4 fps while the slowest only maintained 0.4 fps. The number of shots and frame rate depend on camera settings and the image subject. The detailed scene in this test produced 33.5 MB RAW files and 12.6 MB JPEG files.
When shooting RAW+JPEG, the slowest card reached 17 shots at full frame rate, whereas a fast card could reach up to 22. Frame rate with the buffer full varied from 0.3 fps with slow cards to 1.9 fps with the faster cards. When shooting JPEG only, the slowest card maintained full frame rate for the first 30 shots then dropped to 1.1 fps, while fast cards did not limit JPEG shooting and shot at full frame rate for the 30 second test.
The fastest cards in the Canon 77D were Sony SF-G 300MB/s UHS-II cards. Although these are UHS-II cards, they only function in UHS-I mode in the camera. There is little difference between the fastest UHS-II cards and fast UHS-I cards in the camera. SanDisk Extreme Pro 95MB/s UHS-I cards offer similar write speed in the camera and are a much better value. The Sony M Series UHS-II cards also offer high performance at a lower price point than other UHS-II cards, with the added benefit of fast UHS-II downloads. Kingston U3 90/80 MB/s UHS-I cards offer excellent performance in a UHS-I card.
From a value perspective, the Kingston Class 10 UHS-I 64GB is a good performer at a reasonable price point. The tables above can be sorted by clicking on the column headers and filtered by card capacity.
The Canon 77D has a USB 2.0 port that can be used to transfer images from the camera to a computer. USB 2.0 connections are limited to around 35MB/s at best, and the transfer speed of the 77D measured slightly lower. To test the transfer speed two of the faster SD cards were tested in the camera. Each card contained 5GB of RAW images and the transfer was made using a USB cable connected to a computer with a fast SSD drive to allow the fastest transfer rate. The first card was the Sony SF-G UHS-II 32GB which averaged 31.9 MB/s. The second card, the SanDisk Extreme Pro 95MB/s UHS-I U3 V30 32GB, averaged 31.5 MB/s. While this is reasonable performance for USB 2.0, it is far below the transfer rates provided by a separate USB 3.0 card reader. Transfer rates using UHS-I cards can reach 90MB/s, while UHS-II card can reach over 250MB/s when copying files. Speed tests of memory card readers are provided in the Card Reader Reviews.