The EOS 7D is powered by Dual Digic 4 processors and it shows. The camera's overall performance is nothing short of impressive, especially in this segment of the market. The two processors are pushing the huge 18 megapixel files through the imaging and processing pipeline in an extremely swift manner. Instead of asking if this camera is fast enough for you, you should probably be slightly concerned if you are fast enough for the 7D.
Timings & File Sizes
Timing Notes: All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 5184 x 3456 JPEG Fine (approx. 6,000 KB per image).
The media used for these tests was:
- 32 GB SanDisk Extreme Pro CF card
(32 GB SanDisk)
|Power Off to On *1||0.1|
|Power Off to Shot||<0.1|
|Shot to shot time (JPEG)||
|Shot to shot time (RAW)||
|Switch from live view||0.4|
|Power On to Off *2||2.1|
|*1||This is the time from turning the switch to the 'On' position to shooting information appearing on the top LCD (as soon as you would be able to verify camera settings). It takes approximately 1.0 sec for the status screen to appear on the rear LCD.|
|*2||This is taken up with 'Sensor cleaning' (dust removal), if you disable automatic sensor cleaning the power off time is instant.|
Continuous Drive mode
To test continuous mode the camera had the following settings: Manual Focus, Manual Exposure (1/640 sec, F5.6), ISO 100. Measurements were taken from audio recordings of the tests. Media used were the same as above.
The tests carried out below measured the following results for JPEG and RAW:
- Frame rate - Initial frame rate, this was always 8.0 fps (+/- 0.05 fps)
- Number of frames - Number of frames in a burst (for JPEG there is no limit with a fast card)
- Buffer full rate - Frame rate if shutter release held down after burst (buffer full)
- Write complete - How long after the last shot before the CF lamp goes out
Burst of JPEG Large/Fine images
32 GB SanDisk
|Frame rate||8.0 fps|
|Number of frames||> 320|
|Write complete||~ 1.0 sec|
Burst of RAW images
32 GB GB SanDisk
|Frame rate||8.0 fps|
|Number of frames||24|
|Buffer full rate||4.9*1|
|Write complete||9.4 sec|
|*1||This is the average buffer full rate. Once the buffer is full the EOS 7D falls into a shooting 'rhythm' taking two shots in quick succession (almost normal frame rate) followed by a gap of approximately 0.45 sec.|
At eight frames per second the EOS 7D is the quickest APS-C DSLR that we've seen in our labs so far. The frame rate is impressive on itself and even more so considering that with a very fast card, such as the Sandisk Extreme Pro, in JPEG format the 7D can maintain this speed indefinitely (well, we gave up after approximately 60 sec or 320 frames) and for 24 frames when shooting RAW. Surprisingly that's even better than the official Canon specification (126 frames in JPEG, 15 frames in RAW). The initial frame rate is still maintained when shooting RAW+JPEG but only for seven frames.
There is no doubt that the dual Digic 4 processors are doing an impressive job of pushing the large image files that the 18 megapixel sensor is capturing through the camera's data pipeline. For those who are less in a hurry there is also a three frames per second low-speed continuous mode.
USB transfer speed
To test the EOS 7D's USB speed we transferred approximately 500 MB of images (mixed RAW and JPEG) from a SanDisk Extreme Pro CF card (the same card used in the other readers). With the 7D connected via USB cable, the only transfer method available is WIA - Canon doesn't provide a simple 'mass storage device' feature in the camera (enabling the camera to act as a normal card reader). Because of this a driver is installed when you connect the camera to your computer the first time to ensure the transfer of all your images (as drag-and-drop WIA doesn't support RAW). Transfer speed was pretty quick, not quite getting up there with a good external card reader but quicker than the built-in model on our office PCs.
|EOS 7D USB 2.0 via EOS Utility (WIA)||15.4 MB/sec|
|SanDisk Extreme Pro (using built in USB connector)||14.3 MB/sec|
|SanDisk Extreme Pro in USB 2.0 reader||21.5 MB/sec|
Autofocus speed / accuracy
The EOS 7D's Auto Focus performs very well under any condition. The camera locked the focus very quickly with with Canon's standard and Ultrasonic lenses alike (the latter give you the additional benefit of focusing almost silently). As usual we shot a few hundred real-life sample shots while working on this review and only had a very small number of pictures that were not focused properly. The AF works accurately even in impressively low light levels and only slows down a little bit, so you can relax about the lack of an AF assist light and make good use of the ISO 12800 maximum sensitivity.
We are no sports photographers but we have used the EOS 7D at a sports/action event and even with our limited sports photography skills got a decent proportion of usable shots. Given the flexibility of the EOS 7D's AF system sports photographers who know what they are doing should find it quite easy to set up the system to suit their requirements. This, in combination with the camera's eight frames per second continuous shooting rate, should make the 7D an option for at least those sports photographers who are on a budget or are looking for a more affordable backup for the 1D Mark III or IV.
The contrast detect AF in live view and movie mode is slightly improved over previous Canon DSLRs but is still pretty slow and slightly painful to use. Therefore, as usual, your best bet is to pre-focus or focus manually when using live view.
The EOS 7D uses the same Lithium-Ion LP-E6 battery pack as the EOS 5D Mark II and specified (CIPA) battery life is very similar as well. During the process of this review battery life never really was an issue. For a majority of photographers the 7D's battery should hold at least enough power for a day. Only if you make very extensive use of the camera's continuous shooting capabilities, live view or video it might be worth considering getting an additional battery pack. Canon reports tested battery life as:
50% Flash use
|At 23°C / 73 °F||
|At 0°C / 32°F||