Mark III / Mark IIN - Ring of Fire?

ROF - explanation request on the Mark III and Mark IIN:
C.FN III-8 (Selection 2) AF Expansion... is this the ring of fire? (New term for me) Does the ROF expand automatically as it tracks using the manually selected point without user initialization, or does one have to do something for the feature to expand to the ring around the manually selected focus point?

In simple terms, the ring of fire is Canon's way of saying you have not Manually selected a point, the camera is about to use whatever point it needs to.

gasrocks wrote in post #4453452
In simple terms, the ring of fire is Canon's way of saying you have not Manually selected a point, the camera is about to use whatever point it needs to.

If you use ring of fire, the camera determines, within that ring, what is closest to the camera, locks on that and tracks it as long as you keep it in the ring....But there is more to it than that and would like to hear others thoughts.

GBRandy wrote in post #4453473
If you use ring of fire, the camera determines, within that ring, what is closest to the camera, locks on that and tracks it as long as you keep it in the ring....But there is more to it than that and would like to hear others thoughts.

Am I to understand that I do not choose an AF point, I choose a selection of nine, for example. What are the C.Fn setting(s) for this? Is this C.Fn III-8?

GBRandy wrote in post #4453473
If you use ring of fire, the camera determines, within that ring, what is closest to the camera, locks on that and tracks it as long as you keep it in the ring....But there is more to it than that and would like to hear others thoughts.

It's my understanding that the ROF or AAFPS (Automatic AF Focus Point Selection) focuses on the closest point or points of a subject. If say you are in AI Servo, you have to "start"or "prime the servo using the center point, then it will track the subject if you keep the subject in the ROF. To activate it you don't need to do it through CF's just hit the rightmost button (next to the star, then depending on what body you have (The 1DmkIII for instance) you click the joy stick and it will toggle between a single point (either customized or the center) and the ROF.

No, Custom III-8 activates the AF sensors around the selected single point

I am not sure if I understand this "ring of fire" thing are not. I have my MIIN & MIIIN set on a manual center AF point. In the Custom functions I also choose the tighest right of AF points around the center point, varying for the two cameras. I use the button the back, "*" or "AF" button on the MIII to manage focus lock. Is this the proper setting? Will the camera automaticall expand to the next ring outside the manually selected center point? Will I see it do this?

If not, what are the exact correct settings?

Also, a heavy dose of mexican food will invoke the ring of fire. No custom function necessary, and it's fully automatic!

WAF wrote in post #4479509
I am not sure if I understand this "ring of fire" thing are not. I have my MIIN & MIIIN set on a manual center AF point. In the Custom functions I also choose the tighest right of AF points around the center point, varying for the two cameras. I use the button the back, "*" or "AF" button on the MIII to manage focus lock. Is this the proper setting? Will the camera automaticall expand to the next ring outside the manually selected center point? Will I see it do this?

If not, what are the exact correct settings?

If I understand you correctly you have the assist points surrounding the manual one you select active (from the cust func setting) I've never tried it but that is different from what I described in the above post.

thatkatmat wrote in post #4479829
If I understand you correctly you have the assist points surrounding the manual one you select active (from the cust func setting) I've never tried it but that is different from what I described in the above post.

You are correct. In doing this I cannot see it visually expanding from the single manual point to a "ring" so I don't know if this is the correct setting. It sounds like it is not.

Can you see the ring expand from the single point or do you do this with the toggle to expand it to a ring?

WAF wrote in post #4480327
You are correct. In doing this I cannot see it visually expanding from the single manual point to a "ring" so I don't know if this is the correct setting. It sounds like it is not.

Can you see the ring expand from the single point or do you do this with the toggle to expand it to a ring?

Do it with the toggle.
Just tried your CF 8-3 "surrounding" , they don't light up and this is not what some call the ROF. I believe this is just to assist your single af point, perhaps it helps boost tracking in Servo?? Not sure, but the quick snapps I just took seem to be in focus on the selcted AF point, not any of the surrounding.
Matt