-Official- 1D MK III AF Thread.

I am under the impression that when the assist points are being used, the AF point will light up indicating the focus is shifting to that point.

I have the assist points enabled and have seen this myself when the subject drifts from the specified AF point.

I haven't seen anything to indicate the assist points cause additional AF issues...then again my action/sports/wildlife shooting is rather limited so...

tonylong wrote in post #6317648
I haven't used the AF Assist Points feature, but I'd imagine that the problems mostly arise when the subject, such as a little bird, doesn't fill the focus "box" so that focus would shift to one of the assist points if there was more contrast.

Like I said, I haven't used the AF Assist funtion, and I'd be curious to know: why and how has it worked for you?

nicksan wrote in post #6317786
Ring of Fire...that's when you have the entire "circle" of AF points enabled...the camera will pick the AF point it thinks is best suited.

ryanyboy wrote in post #6317790
Yeah, right............

Well, he "mostly" answered your question! Ring Of Fire is a coined term, not an official Canon term -- you enable all AF points (is it 49 with the Mk III?) and shoot in AI Servo where you initially acquire focus with the center point and then, in theory at least, the focus is handed off from point to point as the subject move.

So, it's not a circle so much as it's a matrix of focus point. The "circle" idea is more related to selective focus points -- you have an inner circle and an outer circle, and you can choose either or both for selective focusing points.

Shooting in ROF mode is useful in some scenarios, such as a bird flying with a sky background where the camera has one object with enough definition to focus on and track. With a more "busy" scene, such as a field full of players, it may actually be a hinderance , but experience is a key here. I, in practice, pretty much stick to center point AF with action scenes and birds, so I can't comment on the effectiveness of ROF or, in relationship to the above discussion, AF Assist points.

tonylong wrote in post #6317862
Well, he "mostly" answered your question! Ring Of Fire is a coined term, not an official Canon term -- you enable all AF points (is it 49 with the Mk III?) and shoot in AI Servo where you initially acquire focus with the center point and then, in theory at least, the focus is handed off from point to point as the subject move.

So, it's not a circle so much as it's a matrix of focus point. The "circle" idea is more related to selective focus points -- you have an inner circle and an outer circle, and you can choose either or both for selective focusing points.

Shooting in ROF mode is useful in some scenarios, such as a bird flying with a sky background where the camera has one object with enough definition to focus on and track. With a more "busy" scene, such as a field full of players, it may actually be a hinderance , but experience is a key here. I, in practice, pretty much stick to center point AF with action scenes and birds, so I can't comment on the effectiveness of ROF or, in relationship to the above discussion, AF Assist points.

Apologies Nicksan - I thought you were being sarcastic.

"Ring OF Fire" makes sense now although with this in mind I would have thought it would have been the inner ring of focus points?

Either way at least I know what ROF stands for now.

Thanks guys

ryanyboy wrote in post #6317979
Apologies Nicksan - I thought you were being sarcastic.

"Ring OF Fire" makes sense now although with this in mind I would have thought it would have been the inner ring of focus points?

Either way at least I know what ROF stands for now.

Thanks guys

You know, I could be all mixed up, because of the internets -- ROF could be just an abbreviation for ROTFL!

Tony explained it better than I did... I guess I was a little lazy in my response!

ryanyboy wrote in post #6317979
Apologies Nicksan - I thought you were being sarcastic.

"Ring OF Fire" makes sense now although with this in mind I would have thought it would have been the inner ring of focus points?

Either way at least I know what ROF stands for now.

Thanks guys

tonylong wrote in post #6317796
I'm wondering specifically about comparing the performance of the AF Assist funtion with just using center point focusing without AF Assist. I haven't had the liberty of experimenting with this in non-critical shooting. I've heard that with the Mk II the AF Assist function is a real enhancement, whereas with the Mk III it can be detrimental, so I've avoided trying it out.

On my body the selected focus point alone works very well does not matter which point I selected, but the moment I try to use AF expansion(C.Fn III - 8 ) the focus becomes very unresponsive.
That was with one shoot and one lens, when I get time I will test that setting again more properly otherwise I will just will have to do without that feature if I cannot tune the camera to work with it. Not worth sending the camera back all the way to the states.

fatphotographer wrote in post #6312847
The US article helps fill in a few gaps. I didn’t think they were just sat around ignoring the issues, but I don’t think they went far enough – anyway, that is just my opinion.

For anyone that is interested, my MK111 is going back to Canon (4th time for this body)in the morning. They sent a loan camera which arrived on Friday and my photographer and I, had the “pleasure” of using the cameras side by side for over 16,000 frames (8000 pictures each body) at a large event over the weekend.

Firstly, the 70-200 2.8 IS that performed abysmally with my body, performed much better on the loan body. I would say that only 10 – 15 % of the pictures were OOF and a small %age of them would be down to me. This is a much better hit rate than my body, but not a rate that I would see as acceptable from Canon’s top body.

My body was used with a 35-350 is the same lighting conditions and had a failure rate of over 20%, if the 70-200 was on that body, I would expect a failure rate of well over 33%.

The loan body has given me a little more hope that the camera can be bettered, but I still feel that it isn’t the camera it should be, for the use it is intended.

It is all well and good, when Canon US claim it is great for weddings and events, but my events involve a large amount of pictures of fast moving vehicles, and it is my view that the MK111 still isn’t up to the job.

There will be a couple of pictures posted in the motorsports section of the better pictures.

As a matter of interest, which event was this? I ask because I was at the LRO (Land Rover Owners) event in Peterborough - and I saw two photographers at the off road coarse, one was using a 35-350 and the other a 70-200, both on MkIII.

As I'd gone round the course, I bought the pictures!

ryanyboy wrote in post #6317979
Apologies Nicksan - I thought you were being sarcastic.

"Ring OF Fire" makes sense now although with this in mind I would have thought it would have been the inner ring of focus points?

Either way at least I know what ROF stands for now.

Thanks guys

Get your 1DmkIII and go through the motion of manually selecting the different AF points. You'll notice that each AF point lights up in red as you select them. When you've gone through all the AF points, what you get next is a ring of red AF points along the outer perimeter of the AF area. This indicated that you have selected all the AF points and focusing is now in automatic focusing point selection mode. That red ring of AF points is where the term "ring of fire" came from.

anglefire wrote in post #6319163
As a matter of interest, which event was this? I ask because I was at the LRO (Land Rover Owners) event in Peterborough - and I saw two photographers at the off road coarse, one was using a 35-350 and the other a 70-200, both on MkIII.

As I'd gone round the course, I bought the pictures!

That was us. I was at the mud run and you would have dealt with one of my daughters or my wife at the unit, my son was running the pictures on his quad. We took over 17,000 pictures that weekend. Thanks for your support, I hope you enjoy your pictures!

Thought it was!

And yes the pictures are good - everyone who's seen them has wondered at first how I took them - as I was driving - and some were impressed that my wife could get such a good shot from inside the car of the outside! (There is one shot you've taken which you can see my wife taking a picture of you!)

Tareq wrote in post #6317740
And which lens did you use on those soccer sports?

70-200. There aren't many sports I can shoot with anything less than this.

Harleypugs wrote in post #6317769
Can you outline your exact settings please?

Jon

Sorry, I've been away for a day.

Here are the C.Fn settings that are not default.

C.Fn III
4 - 1
8 - 2
9 - 3
10 - 1
11 - 2
13 - 1

C.Fn IV
1 - 2

Thanks Tony, excellent explanation. I added a link to your post to the acronym thread.

tonylong wrote in post #6317862
Well, he "mostly" answered your question! Ring Of Fire is a coined term, not an official Canon term -- you enable all AF points (is it 49 with the Mk III?) and shoot in AI Servo where you initially acquire focus with the center point and then, in theory at least, the focus is handed off from point to point as the subject move.

So, it's not a circle so much as it's a matrix of focus point. The "circle" idea is more related to selective focus points -- you have an inner circle and an outer circle, and you can choose either or both for selective focusing points.

Shooting in ROF mode is useful in some scenarios, such as a bird flying with a sky background where the camera has one object with enough definition to focus on and track. With a more "busy" scene, such as a field full of players, it may actually be a hinderance , but experience is a key here. I, in practice, pretty much stick to center point AF with action scenes and birds, so I can't comment on the effectiveness of ROF or, in relationship to the above discussion, AF Assist points.

Hey Jake, did your new camera show up yet?...

saravrose wrote in post #6336808
Hey Jake, did your new camera show up yet?...

yea, hope he gets it soon.

deeeez wrote in post #6336904
yea, hope he gets it soon.

I was looking for confirmation that it had arrived pristine and beautiful and worked like all of his old fantasies when he first bought it.