5DMKIII Autofocus help required

[bjd]

Hi,
I finally got my new 5D, moved up from a 400D, and I am "ashamed" to say I have been doing a lot
of reading in the camera manual
I've been playing with the autofocus settings while trying to take shots of some of the birds in our garden.
Attached an example that is causing me problems. The display will show me the "fields" being used for AF,
and they will all be lined up on the bird feeder. I havent been able to find a way to persuade the camera
to focus on the bird in such a situation. This is in automatic mode. If I go to spot with the 4 adjacent fields
then it seems to work better. But I want the automatic mode so I can use a tripod and set the camera up
as close as possible to the birds. Using AI Focus mode usually.
I am using the 70-200 F4 IS lens, at 200mm and pretty close to the subjects. Do I maybe want to move
further back so that I have more DOF therefore making the exact focus less important.
Generally I haven't been so happy with the results yet, but thats probably more me than the equiment.
Cheers BRian

 

[neuroanatomist]

Automatic AF point selection? That will always pick the closest subject. Some options would be to stop down for deeper DoF, or switch out the round feeder for a directional one (only only perch) and manually focus on that spot.

 

[bjd]

Hi,
thanks for the reply.
Obviously I can do a lot with the situation in our garden, and will get to that but I was more concentrating
on getting it right with the camera first. I guessI was thinking more along the lines that AF was concentrating
more on the horizontal and vertical lines and not the fact that the front edge of that feeder will in a lot of
cases be closer to me than the subject.

Cheers Brian

 

[bdunbar79]

I use AF on my 5D Mark III. In the manual you'll see that you can choose ONE of any of the 61-AF points if you like. I still use only one point, but I move it around the viewfinder. Sometimes I'll use 4 point expansion (top, left, right, bottom) but mainly I move the AF point around where I know or want my subject to be in the frame. I actually haven't had a photo yet where I missed focus. Like the poster above said too, watch your DOF. If you need to use higher ISO with a narrower aperture, do it! The camera will handle it nicely.

 

[bjd]

I use AF on my 5D Mark III. In the manual you'll see that you can choose ONE of any of the 61-AF points if you like. I still use only one point, but I move it around the viewfinder. Sometimes I'll use 4 point expansion (top, left, right, bottom) but mainly I move the AF point around where I know or want my subject to be in the frame. I actually haven't had a photo yet where I missed focus. Like the poster above said too, watch your DOF. If you need to use higher ISO with a narrower aperture, do it! The camera will handle it nicely.

Thanks. OK I saw that and had tried it, allows me to frame the subject where I want it.
Here's another example. Taken F14 1/160th 200mm 1.2meters from the subject. The face of the bird is pretty
sharp now I guess. Is that about the correct quality that I should get from this combination?

Bad hair day?

 

[bdunbar79]

That's pretty good quality. I think you're doing well. The other thing I did was practice different metering and see how it affects the exposure. For instance, you could do spot metering on the bright side of the bird, take the reading, and adjust the shutter speed accordingly for proper exposure. Usually, when I do something like that, I'll take 3-5 photos with AEB, -2/3, -1/3, proper, +1/3, +2/3, and then do two metering sites. You have 10 photos then, and one will certainly be the way you personally want it. That's just what I do. I know it can add a lot of RAW pictures that you're not going to use and have to sift through, but in this case it might be worth trying once or twice and seeing what your options look like. And it's fun! However, in this case you may not have had time to do that, as the bird probably took off within seconds, maybe. I think the 5D Mark III can do spot metering everywhere (all 61 points) in single shot mode can't it? I can't remember. AI Servo is different.

 

[briansquibb]

The DOF seems to be very shallow for F14?

 

[bdunbar79]

The DOF seems to be very shallow for F14?

I was thinking 1.4 personally. In that case, I'd shoot f/8 if I were conerned at all about DOF and in focus subjects with 5D Mk III. If the background interferes too much, practice maybe at f/5.6, then f/4. That's what I usually do.

 

[briansquibb]

The DOF seems to be very shallow for F14?

I was thinking 1.4 personally. In that case, I'd shoot f/8 if I were conerned at all about DOF and in focus subjects with 5D Mk III. If the background interferes too much, practice maybe at f/5.6, then f/4. That's what I usually do.

I am guessing a big crop judging from the bg.

Look at the bg on this pic - ff, f/3.2, hardly cropped, much smoother bg

http://www.canonrumors.com/forum/index.php?topic=819.msg136011#msg136011

 

[bjd]

Hi,
F14, 1/160th, ISO 2000, 200mm at 1.2 Meter distance (according to EXIF). Which according to a DOF calculator gives me a DOF of around 2-3cm. Is it maybe because I am right at the closest possible focusing distance for this lens and therefore have
no DOF to the front of the focus plane like I should have?

Maybe I do really just need to keep away from the "Near" limit of the lens anyway.

Thanks for all the comments. I dont mind sifting through the .RAW files, as long as I do find something
worth keeping in there.


Here's the full picture, not that much of a crop.

 

[Mt Spokane Photography]

F/14 is going to reduce sharpness somewhat due to diffraction, you might actually get a sharper image by moving back a little, using f/5.6 to f/8 and cropping more or using a TC. And, of course, lighting is everything. Sometimes, if the sun is not right, or the subject is in a shadow, a flash is needed.

 

[bdunbar79]

My personal feelings are the same as the poster above. I would have chosen f/8 as my aperture because that would probably have been sharper than f/14, the background isn't as busy, and I also would have backed up a tad and cropped if need be later. I know, this is really nitpicking and there really isn't anything wrong with your shot, but that's how I read the shot. I may have metered on the bright spot of the bird with spot metering but I can't really answer that question since I can't see the whole scene and can't see the sky. Cool shot though!

 

[bjd]

No not picky, those are the things I still need to learn. Thanks.

 

[bjd]

I think the 5D Mark III can do spot metering everywhere (all 61 points) in single shot mode can't it? I can't remember. AI Servo is different.

I was wondering about this. Sure it has the 61 point AF, and I can select any of those points, but is the one I select
also used for metering? In the book it says something about a central area about 1.5% of the total area for spot.
So who knows this for certain?
Cheers Brian

 

[neuroanatomist]

I think the 5D Mark III can do spot metering everywhere (all 61 points) in single shot mode can't it? I can't remember. AI Servo is different.

I was wondering about this. Sure it has the 61 point AF, and I can select any of those points, but is the one I select
also used for metering? In the book it says something about a central area about 1.5% of the total area for spot.
So who knows this for certain?
Cheers Brian

If you're using evaluative metering, weighting is given to the region around the selected AF point. Spot metering on the 5DIII is in the center only, not linked to the AF point selected. AF point-linked spot metering is currently a 1-series only feature.

 

[bdunbar79]

I think the 5D Mark III can do spot metering everywhere (all 61 points) in single shot mode can't it? I can't remember. AI Servo is different.

I was wondering about this. Sure it has the 61 point AF, and I can select any of those points, but is the one I select
also used for metering? In the book it says something about a central area about 1.5% of the total area for spot.
So who knows this for certain?
Cheers Brian

If you're using evaluative metering, weighting is given to the region around the selected AF point. Spot metering on the 5DIII is in the center only, not linked to the AF point selected. AF point-linked spot metering is currently a 1-series only feature.

Thank you thank you. I was thinking of my 1D Mark IV. Good thing I didn't go out and try this. Maybe I shouldn't have two cameras

 

[hoghavemercy]

I think the 5D Mark III can do spot metering everywhere (all 61 points) in single shot mode can't it? I can't remember. AI Servo is different.

I was wondering about this. Sure it has the 61 point AF, and I can select any of those points, but is the one I select
also used for metering? In the book it says something about a central area about 1.5% of the total area for spot.
So who knows this for certain?
Cheers Brian

If you're using evaluative metering, weighting is given to the region around the selected AF point. Spot metering on the 5DIII is in the center only, not linked to the AF point selected. AF point-linked spot metering is currently a 1-series only feature.

Is that possible with a firmware update on the 5DIII??

 

[neuroanatomist]

I think the 5D Mark III can do spot metering everywhere (all 61 points) in single shot mode can't it? I can't remember. AI Servo is different.

I was wondering about this. Sure it has the 61 point AF, and I can select any of those points, but is the one I select
also used for metering? In the book it says something about a central area about 1.5% of the total area for spot.
So who knows this for certain?
Cheers Brian

If you're using evaluative metering, weighting is given to the region around the selected AF point. Spot metering on the 5DIII is in the center only, not linked to the AF point selected. AF point-linked spot metering is currently a 1-series only feature.

Is that possible with a firmware update on the 5DIII??

In theory, yes. Might be a slight technical challenge due to the very tightly-packed 61 AF points, but previous 1-series bodies managed it with pretty tightly-packed 39 AF points and the same 63-zone metering found in the 5DIII. But, practically...based on Canon's history, I really doubt it'll happen.

 

[bjd]

Getting there (I think).
I found the feature that allows me to display the focus points when viewing the picture
and generally its now spot on. I think one problem is trying to shoot very fast moving
subjects at too low a shutter speed. I suspect that was more the problem than incorrect
focus.
Certainly this example seems to be well focussed, DOF is low due to aperture, certainly no
complaints with the equipment anymore.
PEBC = Problem exists behind Camera

5DMK3 F6.7, 1/1000 ISO1600 Canon 70-200 F4 IS at 200mm, 2m to subject.

Cheers

 

[bjd]

So I've got stationary objects sorted I think, and have been playing the last two days with the AF setting
trying to capture birds in flight. I guess I have two use cases I'm trying to master:
1. Already focussed on a bird, and want the AF to follow it when it takes off and flies (more or less)
towards me.
2. Set up the camera so a bird will fly from the left into frame as it lands at the right of the frame.

I have read the 1dX Autofocus guide, but still dont have the focus tracking the way I think it should.
Are there any showstoppers (e.g. aperture) that I should know about that may interfere?
Would anyone be prepared to say which settings they would use?

As I'm mainly trying to shoot small birds, are they maybe too small for the AF? Too fast?

I'm primarily using the 70-200 1:4 L IS zoom.

Also, I didn't find a way to get the actually used AF points to be displayed in ACR or PS (I can see
them on the camera when I review the shots), is that at all possible?

Thanks in advance.