Focusing (AF) on Canon 50D

sherijohnson · December 2, 2008

Anyone else that has gotten one of these cameras.... are you a little frustrated like I am with the autofocusing points? I am just curious. Tonight I was just doing some test shots with a new media card and I had to resort to manual focus to take control of the focusing points I wanted. I think it was just because of the silly shirt my daughter was wearing, it has a serious texture to it and I think the camera was "drawn" to it.

I am not too crazy about selecting the focus points with that little control thing either.

What are your thoughts?

Elaine · December 2, 2008

sherijohnson wrote:

Anyone else that has gotten one of these cameras.... are you a little frustrated like I am with the autofocusing points? I am just curious. Tonight I was just doing some test shots with a new media card and I had to resort to manual focus to take control of the focusing points I wanted. I think it was just because of the silly shirt my daughter was wearing, it has a serious texture to it and I think the camera was "drawn" to it.

I am not too crazy about selecting the focus points with that little control thing either.

What are your thoughts?

On the 40D, you can select focus points with the little controller OR with the big dial on the back. Maybe that would work better for you? It just scrolls around to each one as you roll the dial.

dlplumer · December 2, 2008

I almost always use the center point as a single focus point so I have not had an issue.

Tee Why · December 3, 2008

As mentioned before, I'd change the method by which you change the AF point. I personally like the big wheel in the back myself. Yup, never liked that stupid little joystick to change the AF point.

As for using all the AF points and letting the "dumputer" in the camera decide, it never seems to work from personal experience. I too would recommend using the center AF point as they tend to be the most sensitive and focus on the thing you want, and while maintaining the focus lock by keeping the shutter half pressed, recompose and take your shot. That's probably the best and most effective way to do it. You can also use the AF-ON button as well so you don't have to keep the shutter half pressed (I think).

I personally like custom function 4-1 so I focus with my thumb via the "*" button and use the shutter release to lock exposure settings and also to release the shutter.

sherijohnson · December 3, 2008

I was trying to figure out how to just use the center for focus....but could not figure it out. My old cameras were easier to focus compared to this.

This is my first Canon....so trying to make it feel right and know that I am getting focused images most of the time.

I will try the wheel thing when needed as that is way easier to operate.

Tee Why · December 3, 2008

I think if you are in the joy stick selection mode, you just press down on it and it will select the center point. I think the problem with the joystick mode is that it's too easy to accidentally push the joystick again to move to another point.

The thing that is nice about the wheel is that if you turn the on/off button to the first on location, the wheel does not work. Only when you click it to the second point does the wheel work.

sherijohnson · December 3, 2008

Tee Why wrote:

I think if you are in the joy stick selection mode, you just press down on it and it will select the center point. I think the problem with the joystick mode is that it's too easy to accidentally push the joystick again to move to another point.

The thing that is nice about the wheel is that if you turn the on/off button to the first on location, the wheel does not work. Only when you click it to the second point does the wheel work.

yeah when I first got the camera I didn't realize it has TWO on settings, I always keep it where I can access the wheel, I have never accidentally touched it...yet

sherijohnson · December 3, 2008

Tee Why wrote:

I think if you are in the joy stick selection mode, you just press down on it and it will select the center point. I think the problem with the joystick mode is that it's too easy to accidentally push the joystick again to move to another point.

okay, this here made all the difference in the world, AND it should be noted that in certain modes you cannot select the focusing point that it is selected automatically. they should have made that function a little differently in my opinion.

pathfinder · December 3, 2008

I never use but one AF point at a time. I choose not to allow the camera to choose an AF point, because in my experience, it will frequently choose wrong. The images may be acceptable for a 3x5 image, but not for a 16 x 24 print.

The AF selection algorithm the camera uses, tends to favor straight, high contrast, nearer, very strongly over soft, curved, lower contrast and farther away - like for example focusing on the eyeglass frames rather than the eye itself. Therefore, I choose to define precisely which AF point to use, and where to use it in the image.

I call this riding herd on the AF selection, and I use the control wheel method to do it on a 50D or a 40D, unless it is impossible to match the desired location with an AF point. I avoid focus-recompose if possible.

I do not shoot in any mode but Manual, AV or TV. Once in a great while I might use P mode. These modes do allow you to choose your specific AF point.. The beginner modes - like portrait, or sports, or landscapes - do not allow me to choose the AF point used on my 50D, and that is one of the reasons I do not use those modes.

sherijohnson · December 3, 2008

"I call this riding herd on the AF selection, and I use the control wheel method to do it on a 50D or a 40D, unless it is impossible to match the desired location with an AF point. I avoid focus-recompose if possible."

I am curious, is there a reason not to use the "recompose" method? I would think it is faster when needed?

ziggy53 · December 3, 2008

sherijohnson wrote:

... I am curious, is there a reason not to use the "recompose" method? I would think it is faster when needed?

We have a thread about that:

http://www.dgrin.com/showthread.php?t=5642

pathfinder · December 3, 2008

Where is Fish these days, any way!!??

This is one of the links that explains why focus recompose is a poor choice for nearer subjects.

And another - http://www.bobatkins.com/photography/technical/focus_recompose.html

It is more important to avoid focus recompose for full frame cameras than APS sensor or P&Ss.

Focus recompose works fine for things more than 20-25 feet away, especially if you shoot at f8 or smaller.

sherijohnson · December 3, 2008

Ziggy thank you for pointing me in that direction, I hadn't seen that section of the forum yet and I needed to know about it.

sherijohnson · December 3, 2008

pathfinder wrote:

Where is Fish these days, any way!!??

This is one of the links that explains why focus recompose is a poor choice for nearer subjects.

And another - http://www.bobatkins.com/photography/technical/focus_recompose.html

It is more important to avoid focus recompose for full frame cameras than APS sensor or P&Ss.

Focus recompose works fine for things more than 20-25 feet away, especially if you shoot at f8 or smaller.

Thank you for the bits of wisdom. I needed to know that. I might as well try to have really good habits if possible because I am definitely working my way up to a full frame though I don't have one now unless I shoot 35mm and I sure don't do much of that anymore.

Scott_Quier · December 3, 2008

sherijohnson wrote:

Thank you for the bits of wisdom. I needed to know that. I might as well try to have really good habits if possible because I am definitely working my way up to a full frame though I don't have one now unless I shoot 35mm and I sure don't do much of that anymore.

Sheri,

If you will pardon me, reading this thread inclines me to offer up another little tidbit of wisdom ... and, please take it in the spirit I intended (that is, I'm just trying to help) ....

Here's what I do when I get a new camera and I've found it to be very helpful - hope it is for you as well...

With the camera in my lap, turned on, with a memory card in place, I read the manual, cover to cover. When you get done, set it aside for a day and do it all over again. This helps to hammer it into what I use for a brain

Once I've done that, I pick out some topic in the manual that I've not encountered before (every new camera has new features I've not seen - that's one of the reasons to get a new camera body) and practice that for a while (hour to so). I do this a couple or three times a week for three or four weeks or until I fun out of patience. It's really cool what can be discovered when doig this.

HTH

sherijohnson · December 4, 2008

Scott_Quier wrote:

Sheri,

If you will pardon me, reading this thread inclines me to offer up another little tidbit of wisdom ... and, please take it in the spirit I intended (that is, I'm just trying to help) ....

Here's what I do when I get a new camera and I've found it to be very helpful - hope it is for you as well...

With the camera in my lap, turned on, with a memory card in place, I read the manual, cover to cover. When you get done, set it aside for a day and do it all over again. This helps to hammer it into what I use for a brain

Once I've done that, I pick out some topic in the manual that I've not encountered before (every new camera has new features I've not seen - that's one of the reasons to get a new camera body) and practice that for a while (hour to so). I do this a couple or three times a week for three or four weeks or until I fun out of patience. It's really cool what can be discovered when doig this.

HTH

Scott, Believe it or not, I do this all of the time! Every time I get a new camera, I do the same thing with it just like you said. but this one thing was bugging me and I couldn't quite figure it out on my own. The great part is by starting this thread, I gained more understanding by hearing it in different words, I guess. Thank you, it was taken in just the right way. You are always very helpful here.

mercphoto · December 4, 2008

sherijohnson wrote:

okay, this here made all the difference in the world, AND it should be noted that in certain modes you cannot select the focusing point that it is selected automatically.

That's only if you're using the basic modes, like sports, portrait, etc. If you're using the manual modes (M, Av, Tv, etc) then you have full control over the focusing points. Please tell me you're not using the basic modes...

sherijohnson · December 4, 2008

mercphoto wrote:

That's only if you're using the basic modes, like sports, portrait, etc. If you're using the manual modes (M, Av, Tv, etc) then you have full control over the focusing points. Please tell me you're not using the basic modes...

I have been playing around with a lot of the different modes just to see what looks best. When it is important to get the shot, I will experiment when necessary. I like to compare shots and learn from what I have done.

A little about me, I have been using 35mm SLR cameras since 1987....so the DSLRs are a bit different.

sherijohnson · December 4, 2008

I just wanted to come back and comment about some of the information shared here to confirm in case anyone is reading this for information purposes. I just did a quick test regarding choosing the exact focus point vs. the recompose method and the results prove that focus/recompose does not give you the exact results one would be looking for....so when you have time to select a focus point. I did find the suggestions of other members here very helpful.

kygarden · December 5, 2008

I don't shoot Canon, but I've never let the camera decide where to focus. I always use the multi-directional selector to move the focus point where I want it. Very rarely do I ever let the camera select the focus point. Once you get used to it, it's very quick and easy to move the focus point...like to focus on someones eyes, etc.

And P.S. Yes....focus and recompose can and will sometimes screw up your exposure since it's metering off the scene when you first focus, not when you recompose and shoot. Sure you can use exposure lock and all that but for me, it's not worth the hassle...I just pick my focus point and click.

sherijohnson · December 5, 2008

I wasn't even referring to the exposure but that the point you wanted to focus on will not be the sharpest spot depending of depth of field used. But that brings up a whole different topic that can mess up your perfect picture.

Scott_Quier · December 5, 2008

sherijohnson wrote:

I wasn't even referring to the exposure but that the point you wanted to focus on will not be the sharpest spot depending of depth of field used. But that brings up a whole different topic that can mess up your perfect picture.

There are a couple of custom functions (CF) settings that can be set to seperate the AF from the AE (Automatic Exposure) functions. In summary, it moves the AF activation from the shutter release button to the "*" button on the back of the camera. This allows one to "pre-focus" a shot and wait for the action to arrive and then press the shutter release button to get the AE and the picture all in one motion.

The action of using your thumb on the "*" button to achieve AF is not, at first, very intuitive. But, for me, it took only a very short time for that motion to become second nature.

I don't, off the top of my head, remember the CF functions that need to be set or the values to which they need to be set. But, if you post here that you're interested, I'll post that information when I get back home later this afternoon.

sherijohnson · December 5, 2008

I haven't gotten that far into needing to customize....yet.

sherijohnson · December 20, 2008

Scott_Quier wrote:

There are a couple of custom functions (CF) settings that can be set to seperate the AF from the AE (Automatic Exposure) functions. In summary, it moves the AF activation from the shutter release button to the "*" button on the back of the camera. This allows one to "pre-focus" a shot and wait for the action to arrive and then press the shutter release button to get the AE and the picture all in one motion.

The action of using your thumb on the "*" button to achieve AF is not, at first, very intuitive. But, for me, it took only a very short time for that motion to become second nature.

I don't, off the top of my head, remember the CF functions that need to be set or the values to which they need to be set. But, if you post here that you're interested, I'll post that information when I get back home later this afternoon.

I had to come back and update. I was on the Canon site poking around. There is some EXCELLENT information on there and sure enough it was what you were talking about here. I just played around with this tonight and I feel VERY comfortable with this. I found the settings to use the AF on the back separate from the shutter button, allowing the half press to shutter button to do AE Lock and then focus on back AF.

here is the link related to this topic

http://www.usa.canon.com/dlc/controller?act=GetArticleAct&articleID=2286&productID=229&articleTypeID=5

Scott_Quier · December 20, 2008

sherijohnson wrote:

I had to come back and update. I was on the Canon site poking around. There is some EXCELLENT information on there and sure enough it was what you were talking about here. I just played around with this tonight and I feel VERY comfortable with this. I found the settings to use the AF on the back separate from the shutter button, allowing the half press to shutter button to do AE Lock and then focus on back AF.

here is the link related to this topic

http://www.usa.canon.com/dlc/controller?act=GetArticleAct&articleID=2286&productID=229&articleTypeID=5

You are one of the very few that have felt comfortable with this right away. It took me two tries (separated by months of "waiting for it to gel) before I got comfortable. Even with the second try, it was weeks before it became second nature.

Now, I find it strange when I get a camera in my hands that's not configured that way and it's one of the first configuration items I set when I get a new camera.

sherijohnson · December 20, 2008

For some reason I feel this gives me WAY more control over my focusing and exposure settings than all of that "new" stuff about focus points, etc. I guess it gives me the feel of my 35mm cameras, none of which were Canon. I was strictly a Minolta shooter since 1987 when it came to my gear.

Scott_Quier · December 20, 2008

sherijohnson wrote:

For some reason I feel this gives me WAY more control over my focusing and exposure settings than all of that "new" stuff about focus points, etc. I guess it gives me the feel of my 35mm cameras, none of which were Canon. I was strictly a Minolta shooter since 1987 when it came to my gear.

I agree - I get a greater/stronger sense of control over the camera with the AF separated from the AE and exposure.

Focusing (AF) on Canon 50D

Comments