hogesinwa wrote:
Hi. I have a query for the group. When I look through my viewfinder/eyepiece I see a circle. I also see 4 tiny squares and one larger square. The small squares are arranged N,S,E,W, with the larger square in the centre of the 4.
However, this arrangenent of squares sits to the left hand side of the circle, not in the centre of the circle where I would expect it to be. In fact, the large square sits exactly on the left hand edge of the circle.
This seems to me to be wrong but I do not know how to look it up in my manual because I do not know what terms to search for.
Can anyone enlighten me on either what the error is or else where to s4arch for an answer?
Thanks
Hoges
Hi. I have a query for the group. When I look th... (
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The circle in the center is the area that's measured when using the Spot Meter.
With one large "box" and four smaller ones surrounding it, you have the camera's AF system set to the Expansion Focus Pattern. It's one of five different autofocus patterns available on the 7D. The others are All Points/Auto, Zone Focus, Single Point/Manual and Spot Focus/High Precision Single Point. You an toggle through these modes using the AF button combined with the Function button (7DII has a dedicated "collar" to toggle through seven different patterns).
The reason those five boxes are off center is because you've somehow moved the AF point selection there. You can move it back to the center or around various places within the image area using the "joystick" on the back of the camera. Depending upon how your camera is set up, you may need to press another button first. I have mine set up to re-center the AF selection with a "click" of the joystick and to be able to directly move the selection just by tilting the joystick, without having to press another button first. This setup means it sometimes gets moved by accident, but a "click" of the joystick with my thumb immediately re-centers it.
This is all pretty basic stuff with the 7D's AF system. Did you just recently get the camera and are learning to use it? If so, I strongly recommend downloading the PDF manual (the printed one is highly abridged). Also look for a separate manual just for the AF system (not sure there's one for the 7D.... I know there is for 7DII). Some Youtube videos about the 7D's AF system might be helpful to you, too. There are also some good guide books available, check on Amazon.
The 7D's 19-point AF system is fairly customizable and high performance. (7DII's is even more so in various ways.)
I mostly use Single Point/Manual Selection with my Canon cameras. It's more work, but puts me fully in charge of where the camera and lens focus.
Expansion Point (like you've set up) allows you to select the "starting point" (the larger, center AF point), same as with Single Point, but allows the camera to switch to using those adjacent points if you don't keep the subject exactly under that center point. This can be handy when shooting moving subjects that change direction unexpectedly. You can move the set of points around the image area with the joystick.
Zone Focus looks similar with a group of AF points, but they are all displayed the same, larger size. This limits AF to using only the selected group of points, but leaves it to the camera to decide which of them it uses. I occasionally use Zone when shooting fast moving subjects that are against a very distant background that has little detail, that won't "distract" the AF system. For example, I might use this if photographing birds flying past against a blue sky or distant clouds. Obstructions between the photographer and the subject, that the subject might pass behind, also can "distract" the AF system (there's a setting in the menu to delay this). Zone Focus is sort of like having a gigantic AF point... or maybe a scaled down version of All Points. You can move the Zone group around using the joystick.
All Points/Auto simply enables all the camera's AF points and leaves it to the camera to choose which it will use. I never use this pattern. You cannot move anything around and all selection of AF points is left to the camera. It leaves way too much up to chance and I end up with too many missed focus shots.
Spot Focus/Precision Single Point is probably my second most used (after Single Point). This uses only one point, but it's reduced in size for greater precision. This is handy, for example, if shooting a bird that's sitting among a tangle of branches. You can use the joystick to select any of the camera's 19 AF points in this higher precision manner. One slight drawback is that it's not quite as quick as the regular size Single Point (focus speed and tracking ability are also influenced by the lens type, lens max aperture, ambient light conditions, subject contrast/detail and other factors).
Hope this helps!