Chroma and Luminance noise are better than the 50D overall. The 7D has close to a 1\3 stop advantage at low ISOs and 1 a stop advantage at the higher ISOs. Remember though the 7D has 20% more pixels than a 50D and some of this resolution can be traded for noise reduction with software. All in all I am happy with the noise performance. We are close to the physical limit of what can be done with a 1.6 sensor in terms of noise. If you need lower noise get a full frame large pixel sensor!
Slightly higher than the the 50D, probably no more than 1\3 stop. Use ISO 160 - 200 rather than 100 for maximum dynamic range.
Slightly higher than the 50D, the lens is becoming more of a factor than ever in setting the upper limit on resolution. I would not purchase this camera solely for the resolution increase (18 mp vs 15 mp) but every little bit helps if you have to crop images. Resolution comparison
For now I am using DPP to convert the RAW images to TIF as Canon has not updated the software development kit that Breezebrowser uses to convert 7D files. Adobe Lightroom III beta also produces decent results and I understand the CS4 plugin has been updated. The 7D does produce some pattern artifacts in clean backgrounds and some RAW converters may be better at dealing with them than others but so far after completely processing the image including final sharpening I see little difference in the end result with different RAW converters.
Canon prosumer DSLRs have been handicapped over the last several years with mediocre autofocus systems. Back in 1998 the EOS 3 film camera I was using had the 45 point AF system and moving to the seven point AF system of the digital 10D with it's much more primitive AF system was a step backward. Subsequent cameras 20D, 30D, 40D and 50D all had some small improvements to the AF system but none that seemed to make a significant difference with birds in flight. The 9 point AF systems had the points to far apart to make using all points focus useful and the acquisition and tracking with all points was slow and unpredictable so I quickly abandoned its use. The 1D series of cameras have the 45 point AF system but are expensive and heavy and the problems with the 1D MKIII AF system are still being debated. Finally Canon has made a major change to the AF system in a prosumer camera with the 7D. The 19 point system with the ability to configure all aspects of the focusing system looked like a major change, no doubt due to competition from Nikon.
When I received the 7D I was adamant that if the AF system did not show real world improvement I would return it to the vendor! Towards this end I read the AF portion of the manual thoroughly, and set about testing the performance against my 50D.
I have been happy with the low light autofocus capability of Canon DSLRs in general, often they will focus when I have trouble seeing the object! To test this I autofocus on a low contrast object in a dimly lit room using one shot focus mode and center point AF sensor. I find an object that the camera has some some difficulty locking focus on and then repeatedly switched back and forth from the 7D to the 50D using the same lens to see which camera is better able to acquire a focus lock. I could find no consistent difference between the two cameras. This is to be as expected as both cameras have AF systems rated at -.5 EV. The 10D and 20D would not focus at all on the same target. I used my 100m f2.8 macro lens for this test but found the 18-55mm f5.6 (at 55mm) also would lock focus consistently on the same target with the 7D or 50D. No AF assist beam was used for this test.
Shooting Gulls on Lake Ontario and switching back and forth between the 50D and 7D with the same lens produced a significantly higher yield of in focus keepers with the 7D. The 7D was set to use the center point plus 4 expansion points. This effectively makes for a much larger AF area and keeping the AF area on the subject is therefore easier than with a small AF point.
This is the real challenge for an AF system, which has no reliable way of knowing whether you want the bird or trees in focus. I found that the 7D tended to ignore the trees much better than the 50D once AF had locked on the bird. It was easier to drift off the bird with the 50D and focus the trees, the 7D with 4 expansion points about center maintained focus more consistently. It was not infallible but my percentage of keepers was much better than with the 50D. The key is to acquire focus with the center AF point by taping the AF activation (shutter release or AF start) first until the subject is in focus.AF spot Auto Focus
This allows you to reduce the size of the autofocus point for more precise focusing. For shooting through branches or locking on tiny subjects, this may well be useful though I could see little difference in testing informally. Be aware that the AF point whether spot or not is always bigger than is indicated by the AF target outline in the viewfinder. For AF to work well you need to try to fill the complete AF target area with the subject. I was surprised to find that the 7D would still focus the low light target using the center point with "Spot AF". The time to acquire focus with the Spot AF may have been a little slower.Accessing the AF point or group of points
CF IV -1 allows you to set the Multi-controller to select any one of nineteen AF points or to move a group of points. On the 40 and 50 D it was difficult to reliably select the diagonal points but the 7D Multi- controller is excellent in this regard.
So what about the CFIII AF settings?
For now I am using the defaults. The effect of these is difficult to test and will require considerable time. I was happy with my results using the defaults to date.
Canon 7D Autofocus overviewElectronic Level
Hit the INFO button twice when not previewing an image and the leveling graphic appears on the rear LCD screen. This allows you to level the camera in the horizontal and/or vertical dimension. This is useful for getting the horizon level when shooting landscape and particularly when stitching images together to make a panorama. In the past I would use a hot shoe mounted bubble level for this function which was easily misplaced.Files
7D Raw (CR2) are typically 21-28 mbytes in size and after conversion to TIF they become 30 mbytes (with LZW compression) on disc and occupy 52 mbytes in ram. These are big numbers and close to four times the size of the files from the 10D, 20D era cameras. This will mean you need a fast computer or a lot of patience when moving, storing or processing the.
This camera can make use of UDMA mode 6 cards for faster file writes and reads. This has a big advantage when shooting action. The camera has a stated buffer size when shooting RAW at low ISOs of fifteen but in fact the numbers I am seeing with the fastest UDMA cards suggest 18 - 24 frames are possible before the camera slows down some. This can be useful with a camera that shoots at 8 frames per second. UDMA cards vary in speed. I use Sandisk Extreme IV, but the Extreme III 30 mByte addition works well also and the newer Extreme Pro 90 mBytes ones are even faster but expensive. 16 GBytes holds about 550 RAW images.Highlight Tone Priority
Highlight tone priority increased the "dynamic range" of an image by rolling off the highlights gradually. ISO can only be set from ISO 200 to 6400 when active. The downside of HTP is that it can increase shadow noise. I do not usually use this but it may be useful for scenes of extreme dynamic range. It cannot be applied after the fact with the RAW converter suggesting it is an in camera hardware function.Registering Camera User Settings C1, C2 and C3
One of the features of the Canon 7D and some of the other prosumer EOS cameras often overlooked by photographers is the ability to register (or preset) camera user settings. This is an incredibly useful feature for nature photographers as it allows you to quickly recall several camera functions at once from the exposure command dial.
Updated Aug 26, 2010
The "My menu" menu is the right most menu that shows on the rear LCD screen. This can be setup to show your frequently used menu functions and each function is simply a copy of the same function from the other ten menus. This can be a real time saver as you do not have to search menus to find often used functions. The only downside is that "My menu" only holds six functions. pg. 222 in the manual explains how to set and sort these.
While testing the 7D with both 580 EXII flash and 430 EXII I noticed the manual flash X sync speed to be 1\200 sec when High speed sync was selected and in ETTL it was 1\250 sec but with a distance scale anomaly. The manual states the X sync to be 1\250 sec.Frame rate anomaly
In high speed shooting with the shutter manually set to 1/1000 sec and the lens in manual focus mode (allows the fastest possible frame rate), lens cap on, the maximum continuous frame rate was only around 4-5 fps. The manual warns that the frame rate drops in low light, but I can see no logical reason for this..
This is the first time I have tried doing movies and so far I am happy with the results. I hope to have a brief movie clip on my website shortly.
A useful overview of the new features: B&H 7D Video by a Canon rep in several parts
Another review: Bob Atkins review
Another review: ProPhoto Autofocus test
Update August 2, 2010
Overall I find the autofocus
system is a major upgrade from previous pro sumer models in many
regards but one. The Spot AF mode which is supposed to reduce the
AF sensor point size to allow more precise focusing on small objects. I
had hoped this would be beneficial to me for helping pick off
small objects such as Warblers in shrubs where the surrounding branches
often fool the auto focus. I have repeatedly compared Spot AF
mode to Single Autofocus point mode on small horizontal or vertical
objects and I cannot find any difference whatsoever. If I find the
minimum sized object that the Spot AF point will just detect and then
switch to single point and offset the focus and try to refocus the
object I can see no difference whatsoever between the two modes
cabability. What prompted me to test this is that Canon had
stated that its Spot AF mode uses a smaller optical sensor array
therefore it will not work as well in very low light as the normal
sized AF point. Testing this in low indoor lighting with a subject that
the AF system has trouble with showed no difference between Spot and
normal modes in terms of reliably locking on the dim subject. It seems
to me that Spot mode is not activated, perhaps this is a software glitch or
was simply overlooked. I have tested this on three different 7Ds
manufactured months apart, they behaved the same. If anyone has a 7D
that shows a definite difference in response in Spot AF mode I
would like to hear about it and how it was tested. (my 7D
software was ver 1.2.1 when tested)
One other peeve is how to quickly change the AF pattern. When a bird is flying against a clear sky I use AF assist points but if it drops to below the tree line it is necessary to quickly switch to single point to avoid focusing on the trees. To switch patterns It is necessary to push the M-Fn button after pushing the AF pattern button first. It is difficult to feel the M-Fn button without looking for it, it is very small and designed for smaller fingers than mine. Why is the M-Fn button needed at all, simply toggling the back AF pattern button as we did on earlier models would do the job. The need to look or feel for the M-Fn button takes precious seconds.
Update August 26 2010
I have stoped using the odd valued ISO settings such as 320, 640 etc. in favor of the even values such as 200, 400, 800 etc. There is some evidence that Canon does not change sensor gain until the even values and it is easier to recall sunny 16 rule or standard exposure values based on experience witht the even ISOs.
MyMenu settings have been updated
Firmware was updated to version: 1.2.1
Email: Ken Newcombe
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