Magnificent 7?
Canon says it consulted with 5000 photographers for the design of the EOS 7D, its most feature packed DSLR camera yet. David Kilpatrick finds out if they got it right
Canon's new EOS 7D incorporates many new technologies, the most important being a near-18 million pixel image size on the small APS-C 1.6x factor sensor. This is the highest density of pixels so far for any DSLR. What will strike the buyer first, though, is the change in the position of the on-off switch. After many years of Canon putting switches in some very strange places, the 7D has it neatly placed for your left thumb just under the main control dial.
Autofocus
The 7D has a new AF system along with a new type of focusing screen. There are no physical engravings on the screen and for the first time with any DSLR it's possible to view with a completely plain screen and not see focus markings. At default out-of-the-box settings, there is just a barrel-shaped partial outline of the wide focusing zone. It lacks the straight lines you will find on many focus screens (more about this later) and the shimmering texture of the focus screen grain is all you have for adjusting the dioptre setting.
Then, when you first apply a little shutter pressure, large and clearly outlined focus point rectangles appear in whatever pattern matches the locked AF plane; it may be only a single point, two or three, or a pattern distributed across the zone. As you refocus or the subject moves (in Continuous or AI-Servo AF modes) the 19 available points come alive singly or in groups.
Does it work well? Out of the box, absolutely not. The default 19-point Auto Selection AF setting prefers closer subjects, and averages the setting based on an f/5.6 depth-of-field when more than one point is confirmed. I found that with a typical wide- angle landscape or street scene, focus would be at the bottom of the image, five to 10 feet from the camera. In any crowd shot, the closest figures to the camera would be sharp even if the main subject was much better lit and centrally placed. Closest detected object priority has been a standard Canon default for multi-point AF from inception.
However, the 7D focus array covers a much larger area of the picture than AF modules did when this behaviour was chosen. Selecting the closest point from a tight line of three or a central cluster of five points still ensured the focus was more or less on the middle of the shot. With the 7D, a focus point close to the edge of the frame can take priority over a more distant subject filling the central area.
The instruction manual warns 'since it is inclined to focus the nearest subject, focusing a specific target is harder than with single-point AF or AF point expansion'. But out of the box, switching from 19-point Auto Selection to Single Point manually selected AF means either using a sequence of menu choices (via a new Q button for Quick Menu interactive setting navigation) or a sequence of button presses.
Custom settings
To overcome this and other problems, the 7D requires maybe a day spent studying the manual and learning how the complex interaction of preferences, button assignment and custom settings can be tuned to make the 7D respond predictably.
Setting up the AF to work functionally and reliably is not intuitive. There is a new button marked M-Fn. To take control you must first activate the camera with pressure on the shutter release; then push the AF mode button (the familiar one with five horizontal marks); then 'look through the viewfinder and press the M-Fn button'; then repeatedly press the M-Fn button to move through single-point AF, Zone AF (five areas of grouped points) or 19-point; finally, select your focus point if applicable. You can use Q navigation on the rear screen instead, it's less obscure but actually involves just as many operations.
Control of zones or points in the first two modes is by multiway controller or front and rear wheels. You can best do this while looking through the finder; the top LCD display has no mirroring of the function, not even any change to the visible AF indicator to remind you which mode you are in. Further refinements allow pinpoint AF (reducing the area covered by a single sensor), automatic shift of Zone AF to match vertical or horizontal camera position, and expanded single point AF where adjacent points are allowed to have some effect.
Combined with excellent sensitivity and speed, all this does bring the 7D's AF module more up to the level of Nikon's offerings. The Nikon models work as you expect them to out of the box, the 7D does not. It is possible to assign the AF-On or Star buttons to switch to a preselected focus point or zone when in any mode except 19-point Auto Selection, which is the one mode where you most need to have this function.
The only solution I could find was to assign single central point spot AF to the depth-of-field preview button, placed on the lens mount bottom left. This sacrifices the depth-of-field function
and is not ideally placed. Lens buttons (normally used for Focus Hold) can also be assigned this function. Once set up, this does allow instant switching from 19-point auto to spot focus. It's a poor workround for what should be a default function of one of the more accessible right-thumb buttons.
Screen display
I'm used to focus screens that have permanently visible marks, including 16:9 and APS-C crops on full frame and various metering and focus areas. The 7D's 100% viewfinder focus screen markings do not help with composition, even when a visible centre spot focus or metering circle is enabled.
You can - through a menu that takes some hunting down in the manual - set the M-Fn button to display a grid screen together with a two-way spirit level function. This is one of the best features I've ever seen on a DSLR. It uses the AF display markings to indicate tilt or the horizon, and camera level for getting perfect verticals.
If you get just the central AF marking showing while pressing the M-Fn button, you are within one degree of correct for both. Aim the camera up, and additional rectangles appear above the centre; down, they appear below. Tilt the horizon and they light up on the side which is up. The maximum (two squares away from centre) means six degrees.
Combined with the grid screen, this display is black in daylight, and red under a certain EV level. It stays active after you remove your finger from the M-Fn button, but is cancelled when you take first pressure on the shutter.
This great feature is disabled by default, and to enable it you must dedicate the M-Fn button to the task. Since that button is also the one you can assign for raw+JPEG or raw to JPEG one-shot switching, you have a choice. This applies to many of the custom functions of the 7D. Some offer two button assignment choices, others are limited to a single button and picking one function means you can't have the other.
The focusing screen itself is a new type, bright and with a shimmering look to its granular structure, almost like a superfine microprism. The 1x magnification is impressive, making it the 'largest' visually of all APS-C/DX finders. Even so is not very re- liable for manual focusing by eye, due to the clarity and brightness of the f/4 optimised screen.
Metering link
While the 19-point Auto Selection AF system is prone to 'user error', its links to the new colour sensitive 63-zone evaluative metering are much improved. It seems to be more aware of what's happening across the entire frame. Exposures in this mode were consistent and accurate, reducing the need for AE lock or bracketing regardless of contrast or lighting extremes. If a large area of the subject is very dark or bright, and coincides with the entire active set of AF points, you will get over or under exposed results but small highlights like reflections of the sun off water are ignored.
I was obliged to work with Single-point AF Manual Selection with first pressure AF hold and recompose if I wanted specific subjects to be focused accurately. In this mode the metering is hard-linked to the focus point like a virtual spot-meter. I could find no way to force full area evaluative metering while also using single point focus. This produced widely varying exposures depending on the subject tone. On one subject the total range of exposures given to successive shots was between 1/15s at f/11 and 1/250s at f/11 when the conditions needed 1/125s at f/11.
Switching to centre-weighted metering was the most reliable solution. It may be going back 40 years in metering mode, but the variation in exposures with locked and re-composed subjects was less.
White balance is improved, though some sunny scenes had a cold look even with the Standard picture style. Tungsten and fluorescent indoor shots were not fully corrected, retaining some of the feel of the original lighting. Studio flash using Daylight preset white balance was warm in rendering, even more so if set to Flash white balance.
Comparing the HD video shooting to still capture, the video looks good in light conditions where even the maximum ISO12,800 is struggling to stop movement. Action which looks totally blurred at 1/25s in a still shot appears to be sharp in video. Also, whatever effective ISO speed the video recording is using always looks far better in terms of noise than a still frame, no doubt due to the subsampling to get 1920x1080 out of a 5184x 2916 sensor area.
Extra resolution
The big benefit of the 7D comes with very long lenses for sports or wildlife. I didn't have a 600mm f/4 apo or anything like it to try out. Instead, I had the new 18-135mm f/3.5-5.6 IS kit zoom, the new 15-85mm f/3.5-5.6 IS USM and my own vintage 75-300mm IS USM tele. Though it's a surprisingly good lens for the first of its kind, the 75-300mm is not claimed to be apochromatic and is at its sharpest used from 75mm to 150mm.
The 17.9 million pixel APS-C sensor - equal to more than 40 million pixels on full frame - makes demands on lens resolution and diffraction limited with 4.3(mu)m sensels. Whether or not you can pull whisker-sharp detail from only eight of the available 17.9 million pixels will depend entirely on your lens, and how you use it. The diffraction limited optimum (f/6.7) is only half a stop less than full aperture with many Canon general purpose zooms at the long end.
When the system was able to combine correct exposure with perfect focus the benefit of 17.9 million pixels was clear. Animal fur texture was bitingly sharp, and a comparison with 12 million pixel DSLR shots upscaled to 17 million pixel size always favoured the extra resolution.
Noise was surprisingly obtrusive, but very fine in texture, so the resolution was not affected. There was visible noise in sky blues even at ISO100. The JPEG compression in camera is pretty crude, and results using either Canon Digital Photo Pro or Adobe Camera Raw 5.5 (carefully adjusted) were better from ISO200 to 800.
From 1600 to Hi 12,800 the noise reduction in-camera or using Canon's DPP software produced better results than ACR or Lightroom 2.5, which are not yet fully tuned for 7D files (offering beta support only). Any benefits of the resolution are lost, whether from raw or JPEG. The best way to handle 3200-12,800 images is to downsize them to the final working size required. That might only be six million pixels for many action or low-light shots.
The 7D has an auto-ISO mode where you can set manual exposure and let the camera auto expose by varying the sensitivity. This is very useful in low light. No factorial compensation adjustment is possible, or bracketing. It also has control over high ISO noise reduction (from Off to High).
The pop-up flash of the 7D may appear to be an amateur feature to 1D or 5D series users, who have never had built-in flash. Actually, it's a very useful thing to have in any camera, enabling synchro-sun fill in, second curtain slow speed action effects and straightforward flash pictures on demand, whether or not you have a flashgun with you. I'd count it as a valuable feature on any DSLR. This one goes further, and catches up with competing brands by offering built-in remote wireless multiple flash control. The 7D has its own built-in flash commander, removing the need to buy a separate one or waste the functions of one of your Speedlite guns by having it on-camera.
Now, with the 7D, if you own a couple of compatible Speedlites you can a two-flash off camera set-up waiting to be used.
Video mode
The 7D has a new 'hard' live view or video switch with an activation button. If you set the switch to video mode before turning the camera on, you go straight into a live view with HD crops marks. Pressing the Start/Stop button will do as promised, with unlimited HD video to the capacity of the card. There are the usual warnings about sensor performance with long takes.
AF is possible during filming, with soundtrack noises and disruption of image stability. Manual controls and ISO can be used to get the working aperture wanted for a particular visual effect. There is a stereo microphone input, with a recommendation only to plug in microphones not line-out sources; the built-in mic is mediocre with unpredictable auto-gain effects, and the sound suffers from a slight warbling compression distortion.
Using an external microphone improves the quality, and clipping with high sound levels is well controlled. I tried three different external mic combinations and all worked well. The main problem is the auto sound level during quiet sequences. My country town with a bypass half a mile away ended up sounding like Brand's Hatch.
With frame rates of 24, 25 and 30fps at 1080p sound synchronisation with external recordings, and compatibility with other video system clips, is now superior to any other APS-C format V-DSLR. Slow-motion 50 or 60fps at 720p is a bonus.
The 7D 1080p frame has just a touch more detail than a Nikon 720p frame when both are viewed at 1080p, and the overall look is smoother and softer. Either system can be used to produce a grabbed single frame for news reproduction but the Nikon processing gives something closer to a small in-camera JPEG in look. The 7D is better than previous Canon models, and the overall video quality is now the best 1080p from any DSLR.
Live view
The same switch set to live view does not activate this on switch-on, but when the Start/Stop button is pressed. We are all familiar with live view now, and the system works well. Magnified focusing is valuable for calibrating lens AF (up to 20 lenses can be registered) as well as macro work.
Face Detect is added, but with the non-USM 18-135mm lens focusing in live view mode was already slow and hesitant. Using Face Detect slowed it down even further. The 15-85mm USM zoom was much better, and live view focusing proved the best way to get sharp images from this lens.
There are the usual Quick AF options (using phase detect) and two Silent Shooting modes, including Mode 1 continuous 8fps in live view with no display, no focus tracking, no AE and no mirror action. Mode 2 in live view is particularly quiet, a single faint noise as the picture is taken, then a slightly louder return sound for cocking the shutter when you take pressure off the shutter release. AF or manual focus checking is available up to 10x magnification.
The rear screen is of course 920,000 pixels and three inches. It is sharp and the brightness is well controlled to match viewing conditions. It is not articulated. Constrast is improved by a gapless sandwich design, and - hallelujah! - it's got a toughened scratch-resistant solid glass surface, not the easily damaged plastic of all previous Canon models (and most rivals).
This is a feature we need to see in all DSLRs at this price level.
The lenses
The supplied new 18-135mm f/3.5-5.6 IS non-USM zoom is affordable at under £500 from most retailers. Sharpness is good especially if used around f/8-11. It has strong pincushion distortion at anything above 28mm, it needs chromatic aberration correction at both the wide and the long ends, it doesn't focus anything like close enough when set to 18mm. The micromotor focusing is slow and too noisy even to be considered during video shooting.
The 18-135mm when used with Single Point AF focused accurately and produced a good proportion of 'keepers' despite the distortion, with enough resolution to handle the 18 million pixel sensor and no apparent need for Micro AF adjustment.
Canon sent the new 15-85mm EF-S IS USM lens a couple of days later. It's the first Canon general purpose zoom to feature a 15mm minimum focal length. This is equivalent to a 16mm from Nikon or Sony who have similar ranges (the smaller Canon sensor needs 15mm to match). It's also a more solid lens than the 18-135mm.
The 15-85mm seems to have been made for the 7D. It is a very rugged, large diameter lens (72mm filters) and no attempt has been made to reduce its size or weight at the expense of optical quality. It overtakes the two previous 'best' lenses in this class (the Sony CZ 16-80mm and the Nikon 16-85mm VR) with a little more long end each, low CA, low vignetting, good geometry, and very high resolution. It is also close to £800 in retail price, compared to a little over £500 for the 18-135mm. However, it misfocused unpredictably on a wide variety of subjects in all focus modes. The higher optical quality and the superior USM were overshadowed by the functional success of the longer range, lower cost 18-135mm.
Neither lens is supplied with a lens hood, which in my opinion is like selling a camera without a neckstrap. It's not optional with these big 67mm and 72mm front elements and I lost at least one grab shot because the lens cap had to be on for protection in busy streets.
Conclusions
The 7D is a very well built camera with a magnesium body under the skin, 77-seal weather proofing, much improved design, detailing and controls. Compared to the 5D MkII, it feels better in the hand and more solid. The mirror shutter action is quieter and faster, a gain from the small APS-C sensor.
The viewfinder is the best yet for APS-C, the new screen technology permitting a pure uncluttered groundglass that will no doubt be seen in future models. The improved AF, once tamed by custom settings, can best be judged by waiting for feedback from users; the first rush of reactions on popular websites can probably be ignored. It's very unlikely that half the cameras sold are actually going back to Canon for calibration or being returned for refunds because of focus problems.
The image quality is much as you would expect from such a packed sensor. Noise is clearly visible in plain areas of mid-tone, even at ISO100, and shows a tendency to form regular patterns, more visible in lighter tones than dark. In-camera and Canon DPP noise reduction at higher ISO settings is aggressive and removes fine detail; careful processing using Adobe Camera Raw or Lightroom, even though not yet officially optimised for the 7D, preserves textures better.
As has been reported here and elsewhere, the 7D sensor may, if maximum sequence shooting rate is used with extreme overexposure, leave a trace image of high contrast outlines on the subsequent frame. It only shows if the levels or adjustment during raw processing are extreme, two stops or more to recover normal mid-tone values. It is an effect we have not seen before, and Canon promises that a firmware fix will cure it. Since it's very unusual to overexpose a fast action sequence by two to three stops, and the problem is absent with normal exposure or underexposure, it could easily have remained undiscovered for much longer.
To list the additional small improvements and functions present in the 7D would take several more pages. This is one camera where seminars, online tuition, expert dealer help and above all detailed, in-depth study of the manual will be repaid many times over in assured and confident operation.
But you would be foolhardy to buy a 7D over the counter and trust it for a wedding, football match or press call without first testing the system and setting it up to work predictably and accurately with your own lenses and shooting technique.
Centre spot focusing
The range of the new 15-85mm is impressive, from 25mm wide-angle equivalent to 0.21x close-up at minimum focus and 85mm. Centre spot focusing provided the most reliable AF setting for both these shots taken in quick succession at ISO200.
