Canon EOS 7D Performance, Timings, and Image Quality

by J. Keenan Reads (5,694)

PERFORMANCE
Aside from smoothing the pixel gap in the Canon sensor lineup, the 7D gives Canon a good performing camera at a price range that just happens to also fit into a gulf between the $1100 MSRP of the 50D and the $2700 ticket to ride with a 5DII. Price or pixels – take your pick and
Canon has you covered either way.

Shooting Performance
The 7D, like any higher performance DSLR, starts and shoots virtually instantly. Sensor cleaning when the 7D power switch is set to ON or OFF is the default, and on startup takes a little over 3 seconds. You can abort the sensor cleaning by going to a half push on the shutter button to begin shooting immediately, or the cleaning can be disabled via internal menu.

Shutter lag is basically non-existent and AF acquisition time is excellent as well, with the figures coming in at 0.02 and 0.17 seconds, respectively. Single shot-to shot times (shoot, write, reacquire focus and shoot) are practically as fast as you can get off the first shot, lift off the shutter and take the next shot – something in the order of 0.8 seconds.

Shutter Lag (press-to-capture, pre-focused)

Camera Time (seconds)
Canon EOS 7D 0.02
Nikon D300S 0.02
Pentax K20 0.04
Panasonic Lumix DMC-GH1 0.06

AF Acquisition (press-to-capture, no pre-focus)

Camera Time (seconds)
Nikon D300S 0.15
Canon EOS 7D 0.17
Pentax K20 0.28
Panasonic Lumix DMC-GH1 0.37

Continuous Shooting

Camera Frames Framerate
Canon EOS 7D 160 8.0 fps
Nikon D300S 14 6.9 fps
Pentax K20 38 3.0 fps
Panasonic Lumix DMC-GH1 5 2.8 fps

*Note: Continuous shooting framerates are based on the camera’s fastest full-resolution JPEG continuous shooting mode, using the fastest media type available (300x CF, SDHC, etc.). “Frames” notes the number of captures recorded per burst before the camera stops/slows to clear the buffer.

Continuous shooting speed can be as fast as 8fps – faster than anything from Sony, Pentax, Olympus and Fuji; matched by the Nikon D300/300S with the optional MB-D10 battery pack and surpassed only by the Nikon D3 and Canon EOS 1D/III and IV. Using Lexar UDMA 300X CF cards I got between 16 and 20 continuous RAW files at the 8fps rate before the 7D needed a short break.

Canon EOS 7D

Using a 600X SanDisk Extreme Pro UDMA 6 card, the camera also captured 16 to 20 files before stopping, but write times with the 600X card were significantly better – about 6.5 seconds to clear the buffer versus 11 seconds with the 300X.

Our studio tests got 160 JPEGS, only about 140 more than the longest sequence I’ve ever shot in the field. Here are four shots from a sequence at 8fps – the advantage of the higher speeds is you get the “in between” shots the 4 and 5 fps cameras miss. If you compare the first and third shots and particularly the second and fourth, you can get an idea of how much can be missed shooting at the lower rates.

Canon EOS 7D
Burst Shooting Frame 1
Canon EOS 7D
Burst Shooting Frame 2
Canon EOS 7D
Burst Shooting Frame 3
Canon EOS 7D
Burst Shooting Frame 4

The EOS 7D carries a new Canon AF system consisting of 19 cross-point sensors (cross-point sensors can establish focus in both horizontal and vertical planes). There are 5 AF area selection modes: single point (manually selected); zone AF (the 19 points can divided into 5 separate zones covering various portions of the field of view); auto select 19 point AF (used in the fully auto and creative auto shooting modes); spot AF (same as point AF but the AF point covers a smaller area than in point AF) and AF point expansion (manual selection of the active point and adjacent points are then also used to aid with focus).

Any of the modes worked well with static subjects, although users should keep in mind when using the auto select or zone methods that all AF points in the selected zone are used to acquire focus and will tend to focus on the nearest subject. For moving subjects I found that AF point expansion worked best – but only after some trial and error. In addition to simply selecting the AF point expansion mode, I ultimately ended up adjusting the AI Servo tracking sensitivity to slow in order to get the best results.

The higher performance DSLRs have a myriad of settings in various menus that impact their performance, and fine tuning these combinations is the key to realizing the full potential of any camera. I shot over 2500 captures in preparing this review, many of them sequences testing the ability of the 7D to acquire and/or keep focus on moving subjects.

Here are six shots from a sequence of thirteen tracking a single gull through some crowded airspace – the 7D did a pretty good job of not losing track of the bird despite a lot of movement in and out of the frame. These were made with the 200mm lens at f/4 to pick up some shutter speed and within thirty feet of the birds so depth of field was fairly shallow. Overall the 7D handles moving subjects well with the right settings in the camera – it’s not perfect and will lose track every so often, but it turned in a decent performance.

Canon EOS 7D Canon EOS 7D
Canon EOS 7D Canon EOS 7D
Canon EOS 7D Canon EOS 7D

The 7D built-in flash has a guide number of 39 at ISO 100, which translates into a range of about 10 feet with the lens set at f/4. Recycle times in moderately lit conditions with a fully charged battery ran only a second or so – and Canon lists three seconds as the nominal recycle rate. When shooting in aperture priority, the flash can be set to fire and illuminate a subject in the foreground while the camera holds the shutter open an extended period to use natural light to expose the background. In this example, the owl in the foreground is lit by the flash while the castle is exposed for the ambient light.

Canon EOS 7D

Canon EOS 7D

The 7D flash can also act as the master unit with Canon Speedlite flashes with wireless slave capability and remotely trigger these other flashes to fire.

Canon rates the 7D battery for about 800 shots with no live view shooting and 50% flash usage; that figure drops to about 220 shots using live view and 50% flash. Continuous live view shooting lasts about 90 minutes.

Lens Performance
Canon provided an EF-S 17-85mm f4-5.6 IS USM zoom lens for this review, and also an EF 200mm f2 L IS USM to help us better explore the 7D’s potential for sports and action shots with that 8 fps motor. Here’s what the wide and telephoto ends of the zoom look like, as well as the 200mm.

Canon EOS 7D
17mm wide angle

Canon EOS 7D
85mm telephoto

Canon EOS 7D
200mm telephoto

Because the 17-85 is not being offered as a kit lens with the 7D I’ll just briefly comment that it proved to be a nice walking around lens, not overly fast and exhibiting some barrel and pincushion distortion with straight lines in images. One advantage of the DSLR is that there are usually a large number of lenses available to mate with the body depending on your particular shooting need(s). The 7D accepts both EF and EF-S lenses, which total over sixty at last count.

Video Quality
Video quality out of the 7D at the 1920x1080p HD resolution is good – our demo videos were shot at the “cinema” speed of 24fps, but 30 and 25fps speeds are available as well. The 7D uses a CMOS sensor for video and still image capture, and that type sensor can be subject to “rolling shutter effect” which causes vertical stationary objects to appear to be bending as the camera pans across the scene. The 7D does exhibit this effect, which is slight at normal panning speeds but can be greatly exaggerated by panning quickly back and forth at, frankly, speeds that no reasonable person would ordinarily employ. Panning to follow a fast jet at an air show would be one example where the effect might be more objectionable without purposely trying to initiate the phenomenon.

Reduced resolutions of 1280x720p and 640x480p are also available at 50 and 60 fps rates. Regardless of resolution, video length is limited to 4GB or 29 minutes 59 seconds. AF is available at the start of recording, but continuous AF is not provided. Manual focus and zoom are available, and the 7D also allows for manual exposure in addition to automatic.

Video recording is a simple matter of setting the live view shooting/movie shooting switch to the red “movie” icon, acquiring focus automatically by means of a half push of the shutter or full push of the AF ON button (or focus manually) and pushing the start/stop button to initiate capture. A second push stops recording. As heavy as the 7D is with even the lightest of lenses, a tripod or some other form of camera support is a good idea for extended video shoots. Holding the 7D and lens with even partially extended arms in order to see the monitor will get tiring pretty quickly.

Image Quality
Shortly after the 7D reached market Canon issued a firmware update to correct a problem with ghost-like images in some 7D captures: “In images captured by continuous shooting, and under certain conditions, barely noticeable traces of the immediately preceding frame may be visible. This phenomenon is not noticeable in an image with optimal exposure. The phenomenon may become more noticeable if a retouching process such as level compensation is applied to emphasize the image.”

Our demo model 7D displayed no traces of the problem for over 2000 shots, but checking a sequence from an overcast day at the beach I found one example of the phenomenon: two shots of a gull with the ghostly outline of the preceding shot appearing on the second. While I use a calibrated 24 inch LCD monitor to review shots and made the discovery on that screen, the ghost was faintly visible on a 5×7 print I made of the image.

Here are the two shots as they came out of the camera:

Canon EOS 7D Canon EOS 7D

In any event, the firmware update has reportedly fixed the problem, which was subtle, at least on our problem image. Folks contemplating moving into a 7D should plan to update the firmware if their camera hasn’t had the latest version installed at the factory.

Default images out of the 7D were generally pleasing with regard to color fidelity, contrast and sharpness, but are output at 72 dpi which results in a 72×48 inch image at 100% enlargement – you’re going to be resizing for both printing or internet/email usage.

Canon EOS 7D Canon EOS 7D
Canon EOS 7D Canon EOS 7D

Not sure what Canon’s thinking is on this one – if the images are output at 300 dpi that resolution is excellent for printing as is, and you’re left with resizing for internet/email only.

And while we’re on the subject of image size, let’s talk about those 18 megapixel resolution files. Conventional wisdom holds that the higher resolutions tend to be attractive to folks who do landscape or scenic shots where the higher pixel counts bring out greater detail in those wide vistas. Studio work is also mentioned – the ability to bring out detail in portraits, or commercial products for example. And finally, more resolution means larger files which can then be cropped more aggressively yet still retain good photo quality, or, in the absence of cropping produce larger images.

Cropping is a useful tool to improve images as long as the perspective of the shot isn’t ruined – composing the shot as it will finally appear in the camera is always preferable to a composition that will need surgery in the computer later. Here’s the original and a cropped version of an Anna’s hummingbird – both at 15×10 inch size with the original at 345 dpi and the crop at 247 dpi.

Canon EOS 7D Canon EOS 7D

With many competitors’ cameras carrying 12 megapixel class sensors, the 18 megapixel sensor of the 7D enjoys an almost 50% advantage in pixels. The 7D has sensor pixel dimension of 5184×3456 to produce that 18 megapixels; a Nikon D300s has pixel dimensions of 4288×2848 to produce 12.3 MP.

If we resize both files to 300 dpi for printing, we get a 17.28×11.52 inch print out of the 7D and a 14.29×9.49 inch print out of the D300s. So 50% more pixels doesn’t get you a 50% larger print. There’s more to work with, but perhaps not the sweeping amount many folks might expect out of such a seemingly large boost in resolution.

The 7D offers evaluative, partial (9.3% at the center of the screen), spot (2.3% at the center of the screen) and center-weighted metering options, with evaluative being the default. In practice, evaluative worked well for a variety of conditions and was used for the captures in this review. The 7D fairly consistently lost highlights in the high contrast surf shots I try to use to test metering systems. However, the highlights were barely being lost and 1/3EV under exposure compensation fixed virtually all the problems.

The 7D offers a highlight tone priority setting that seeks to expand the camera’s dynamic range between the standard 18% gray and bright highlights, smoothing out the gradation between grays and highlights. Highlight tone priority helped with the highlights as evidenced by histograms of individual shots, but with the downside that ISO settings from 200 to 6400 are required – the 100 to 200 ISO range is disabled when this setting is enabled.

Canon’s picture style effects offer image effects that can be selected to complement a shooting style or subject. Here are the standard, portrait, landscape, neutral, faithful, and monochrome effects. Individual characteristics of each effect (sharpness, contrast, saturation and color tone) can be further adjusted by the user.

Canon EOS 7D
Standard
Canon EOS 7D
Portrait
Canon EOS 7D
Landscape
Canon EOS 7D
Neutral
Canon EOS 7D
Faithful
Canon EOS 7D
Monochrome

Auto white balance worked well for most lighting conditions and shot warm under incandescent light. The 7D also offers daylight, shade, cloudy, tungsten, white fluorescent, flash, custom and color temperature settings.

Canon EOS 7D
Auto White Balance, 3200k incandescent light

Generally, adding pixels to the same physical sized sensor increases noise in digital captures – both the additional pixels and their smaller size are largely to blame. But it’s also true that technology inexorably marches on and that may be why the 7D noise performance came as a pleasant surprise. The camera doesn’t re-write the book on low ISO noise performance, but by the same token noise performance didn’t take the hit I thought it would, at least to my eyes.

Canon EOS 7D
ISO 100
Canon EOS 7D
ISO 100, 100% crop
Canon EOS 7D
ISO 200
Canon EOS 7D
ISO 200, 100% crop
Canon EOS 7D
ISO 400
Canon EOS 7D
ISO 400, 100% crop
Canon EOS 7D
ISO 800
Canon EOS 7D
ISO 800, 100% crop
Canon EOS 7D
ISO 1600
Canon EOS 7D
ISO 1600, 100% crop
Canon EOS 7D
ISO 3200
Canon EOS 7D
ISO 3200, 100% crop
Canon EOS 7D
ISO 4000
Canon EOS 7D
ISO 4000, 100% crop
Canon EOS 7D
ISO 5000
Canon EOS 7D
ISO 5000, 100% crop
Canon EOS 7D
ISO 6400
Canon EOS 7D
ISO 6400, 100% crop

ISO 100 and 200 are quite clean and hard to tell apart – 400 is quite good but showing just a hint of noise and 800 a bit more. ISO 1600 is still fairly good but showing more noise, and 3200 has dropped off even more. The biggest individual drop looks to be between 3200 and 6400, both of which I’d try to avoid if possible. The 7D has “standard” high ISO noise reduction enabled as a default and the camera actually applies noise reduction at all ISO speeds – in the low ISO range the effect is primarily reduction of noise in shadow areas. There are also “low” and “strong” reduction settings, as well as a disable option.

Additional Sample Images

Canon EOS 7D Canon EOS 7D
Canon EOS 7D Canon EOS 7D
Canon EOS 7D Canon EOS 7D
Canon EOS 7D Canon EOS 7D


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