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Discussion Starter #1
This is a what do you use type post.
For the Canon 7D users out there, what AF mode do you use?
  • Manual AF point selection mode
  • Spot AF point selection mode
  • AF point expansion mode
  • Automatic AF point selection mode
  • Zone AF mode
Then what do you use for shot mode?
  • One-Shot AF
  • AI Servo AF
  • AI Focus AF
I have been playing around with the different modes, and wondering which you find the most useful.

I find the Automatic AF point selection mode in one shot AF a lot of those photos are hit and miss as far as focus goes.

So I have been using AF point expansion mode & Manual AF point selection mode in one shot mode.

I primarily have been shooting portraits

Please explain what type of shots you take in which modes.
 

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I use the center focus oints 90% of the time.

I also set my focus points that when I take a portrait photo it automatically uses one focus point higher than the center so when I focus on their eyes the top of their heads fills the frame 80%.

You can select this feature in the custom menu.

For sports I use again the center focus point but enable the assists points around it. I guess center zone can work here too.

I never use the auto focus points selection.

If I want to have the subject to 1/3rd rule, I would select a single focus point manually.

Single shot is always one shot for me.
 

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Hi talljak, its under the C.Fn III: Auto focus / Drive menu.

III-12: Orientation linked AF point
0: Same for both vertic./horiz.
1: Select different AF points

This is a great feature. :)
 

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This is a what do you use type post.
For the Canon 7D users out there, what AF mode do you use?
  • Manual AF point selection mode
  • Spot AF point selection mode
  • AF point expansion mode
  • Automatic AF point selection mode
  • Zone AF mode
Then what do you use for shot mode?
  • One-Shot AF
  • AI Servo AF
  • AI Focus AF
I have been playing around with the different modes, and wondering which you find the most useful.

I find the Automatic AF point selection mode in one shot AF a lot of those photos are hit and miss as far as focus goes.

So I have been using AF point expansion mode & Manual AF point selection mode in one shot mode.

I primarily have been shooting portraits

Please explain what type of shots you take in which modes.
Talljack,

I don't own a 7D so I can't speak towards the newer AF modes ...
I ALWAYS use the centre AF point and focus and recompose (usually on the eyes) when shooting portraits - in one-shot mode.

For sports I use AI-Servo with the Centre Point and, like Yammon, "AF-Point Expansion" which is what the Custom Function you are looking for is called.

Having 19 AF points for the camera to mis-focus on is bad enough - try having 45 :eek:
 

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Discussion Starter #6
Thanks for your input guys. I appreciate it.
Ive set things to center point expanded and things have been a lot better.
 

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An Ongoing Problem

When autofocus appeared as a feature, it was nice, but also introduced new potential problems.

The various cameras obviously have algorithms built into them to help them focus on the desired subject. I recall with an early model, aiming my camera at a stage wanting to get two subjects who were standing in a line in the same frame. That is, the centre of the frame was the background curtain, but the left and right sides had the subjects of interest. I recall being amazed as the camera ignored the centre autofocus point and did what I wanted automatically.

However, as the number of focus points increased, as someone else suggested so does the opportunity for getting it wrong. For a wide angle lens this may not be a serious problem, but for a telephoto it can be.

I have noticed that for my new Canon cameras, the object put into focus is biased towards brightness. If there is a choice, the camera chooses the brighter object. Also, if there is a choice, the camera chooses the nearer object. Sometimes this can be very irritating. If exposure is linked to autofocus, then when the camera chooses a brighter object (not desired by the photographer), then the exposure will not be proper.

Additionally, various lenses seem to have their own focusing algorithms. For example, when I initially aim at an object with a Sigma lens and the focus is slightly off, the lens invariably adjusts in the wrong direction. When I am in a hurry, this can be very irritating. I suspect that this is a holdover from the time when Sigma made many lenses for Nikon. Nikon lenses turn in the opposite direction than do Canon lenses to achieve the same focusing result.

A firmware update, Sigma?

Finally, clearly the choice of focusing method is very closely linked to the type of photography done. With my old 1D Mark II, I set it up so that when I pressed a button, the camera switched focus to the centre point from an automatic setting. This gave me instant remedial control when auto screwed up.

With the 7D, I use the difficult-to-set-up centre point. Not the centre sensor, but a centre point. When you choose the centre sensor, you see a little box in the viewfinder which shows the focus point coverage. However, there is a finer setting whereby a very small black spot appears within this box. In the manual, Canon warns that this setting may result in autofocus failure. Nevertheless, I prefer this setting for outdoor wildlife photography.
 

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Discussion Starter #8
Yea with the jump up from my 40D to the 7D there are more AF points but doesn't always make it better.
I have the point AF turned off in the custom functions as its something I do not need.
I do find switching through focus modes is a lot more complex then it was on the 40D. I guess its due to all the different focus modes.
 

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I'm not sure if this is true with the 7D model specifically, but I know for many (Canon) dSLRs, the center focus point is supposed to be more sensitive when paired with a fast (F2.8 or wider) lens. For this reason, I've gravitated towards using the center focus point as much as possible (although I don't have a 7D). The flipside of course being the wider the aperture, the shallower the depth of field, and shifting the plane of focus then becomes an issue when focusing using the center point then having to recompose/re-frame the image.
 

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Sorry if this is a ridiculous question, but do the Canon IS lenses also have a manual focus option and if they do, is it done with a twist and is it split screen like the old film SLRs?

I'm thinking of moving up from my G7 and one of the things that agravates me about auto focus is, with wildlife photos, it's not uncommon to have a branch or piece of vegetation between me and my subject. It's very frustrating to download and find that the subject is slightly out of focus because the camera thought the branch was the subject. Manual focus is next to useless on the G7 as it's not split screen.
 

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Sorry if this is a ridiculous question, but do the Canon IS lenses also have a manual focus option and if they do, is it done with a twist and is it split screen like the old film SLRs?

I'm thinking of moving up from my G7 and one of the things that agravates me about auto focus is, with wildlife photos, it's not uncommon to have a branch or piece of vegetation between me and my subject. It's very frustrating to download and find that the subject is slightly out of focus because the camera thought the branch was the subject. Manual focus is next to useless on the G7 as it's not split screen.
No such thing as a ridculous question - just the answers sometimes :p

Yes, All Canon EF lenses support manual and automatic focus via a switch on the lens. Yes, there is still a focus ring but EF lenses are missing a Aperture Ring and many a depth of field scale under the distance window (some are even missing the distance window).

Split Screen prisms are available as optional focusing screens for some XXD (i.e 40D, 50D), the XD series (i.e. 5D, 7D) as well as the 1D(s) series. Though replacing the focusing screen with a split screen will disable your spot metering if the body only supports the center spot metering.

Most advanced Point and Shoot cameras can be set to manual focus which usually involves using live view and is typically used for macro mode (my G10, for example) as can any more recent Canon body.

The higher end bodies also have custom functions (usually for sports) where in Artificial Intelligence Servo Auto Focus Mode (AI Servo AF) you can tell the body to ignore things much closer than the point being tracked (say for when your focused on a player and another walks between you and them).
 

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I'm not sure if this is true with the 7D model specifically, but I know for many (Canon) dSLRs, the center focus point is supposed to be more sensitive when paired with a fast (F2.8 or wider) lens. For this reason, I've gravitated towards using the center focus point as much as possible (although I don't have a 7D). The flipside of course being the wider the aperture, the shallower the depth of field, and shifting the plane of focus then becomes an issue when focusing using the center point then having to recompose/re-frame the image.
All current Canon bodies have a cross type sensor as the centre point. Most AF points are Horizontal line sensitive meaning they focus best on horizontal lines. A cross sensor works well with both horizontal & vertical lines and thus focuses much more accurately and is recommended for lenses faster than f/4 or so.

I believe the 5 & 7D have multiple cross sensors, usually clustered around the centre and the 40 & 50Ds may have multiple as well. The 1D(s) models tend to have more cross sensors and the AF is also more sensitive so AF can be achieved with slower lenses (or fast lenses with teleconvertors)
 

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Gordon maybe on the 1 series the focus points are F4, but on the 7D all the focus points are only F5.6 cross type and the center extra sensitive at F2.8.

The 5D II just the center is cross type at F2.8 and the outer are just F5.6 and not cross type.
 

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I use only centre focus for horizontal and use top left point for vertical (usually where the eye of my subject is located in a vertical shot). The multiple focus point, AI focus, they are all more of hindrance (to me) than just one point focus. Maybe because I'm just not used to those modes.
 

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I use only centre focus for horizontal and use top left point for vertical (usually where the eye of my subject is located in a vertical shot). The multiple focus point, AI focus, they are all more of hindrance (to me) than just one point focus. Maybe because I'm just not used to those modes.
LOL - yes, remember the split focus prisms in film bodies. It's nature for me to focus & recompose.

I've been contemplating buying a Zeiss 85/f1.4 for Canon (the EZ mount) and putting a split focusing screen in my body - back to 1976 with my Canon AE-1 & Nikon FM!
 
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