AI Servo tracking sensitivity

[Roy Churchill]

Since getting my 7D about six months ago I have always had the sensitivity set to slow, mainly for BIF. About this time of the year I get my macro lens out and often use it in AI servo mode, I was wondering if it would be an advantage to set the tracking sensitivity speed higher for this type of shooting.
I have read that a slow tracking is best for large slow flyers but for small quick flyers then a fast tracking is best.What tracking sensitivity do you use and do you change it for different situations?

[zanmilligan]

I have the sensitivity set to mid-low, mainly because I shoot a lot from boats where it's difficult to track accurately, so I need a compromise - I don't want the camera to lose the bird too easily, but at the same time if I do lose the subject I want to be able to get it back fairly quickly. I personally found slow was just a bit too sluggish, but this one's not bad.

I haven't bothered changing it for other situations as I find this works fine for most of the photography I do.

[Grant Atkinson]

Hi Roy, I use a pair of 7Ds for all kinds of wildlife photog. I started out with Sensitivity on Slow but now keep it on Fast, as it feels like it takes too long to find something initially. Most of the time I am not shooting at subjects that come in random directions and speeds, and I also sa lot from moving boats. Also have recently switched the C. Fn that prioritizes AF over shutter release to Release first, then AF tracking with great results, it seems to help me acquire the moving subject noticeably faster ( i read that tip on a BPN discussion)
Good luck
Grant

[Grant Atkinson]

Roy, sorry for the typing error in my reply above, I meant to write that I AM shooting at subjects that come from random directions and speeds...hence it isnt easy to be pre-focused.
cheers
Grant

[Roy Churchill]

Hi Roy, I use a pair of 7Ds for all kinds of wildlife photog. I started out with Sensitivity on Slow but now keep it on Fast, as it feels like it takes too long to find something initially. Most of the time I am not shooting at subjects that come in random directions and speeds, and I also sa lot from moving boats. Also have recently switched the C. Fn that prioritizes AF over shutter release to Release first, then AF tracking with great results, it seems to help me acquire the moving subject noticeably faster ( i read that tip on a BPN discussion)
Good luck
Grant
That's interesting Grant, I have sometimes thought that it is a little slow finding the initial lock - I might try it on fast as an experiment.

[Grant Atkinson]

Hi Roy, it is worth trying out. I think if you shoot from a steady platform, and have some idea of the subject distance, then some of the 7D custom AF settings can really help optimize it for certain situations. My testing has been neither scientific nor repeatable really, but I do get lots of practice at fast moving subjects....
I found the 7D AF pretty good. Also if you go to this link http://web.canon.jp/imaging/eosd/eos1dm3af/index.html there are explanations and scenarios for setting up the AF custom functions that I found much easier to understand than in the manual, although this is for the 1Dmk3 I am assuming many of the settings are similar.
cheers
Grant

[Jeff Cashdollar]

Grant - nice read - thanks.

[Allen Johnson]

I believe Arthur Morris has a PDF for the 7D, I bought the one for the Mark IV and will try it out this weekend.

[Roy Churchill]

Just a quick update - I have tried setting the sensitivity to Fast and also the mid point for small perched (but moving birds) and it is too fast, the moment you lose the bird it latches onto to something else. I have not yet tried a faster sensitivity for flyers but for the time being I have set it back to slow.
There is nothing like trying things for yourself I guess - at the end of the day it is what works best for you. Although I do think that different situation call for different sensitivity speeds.

[Roger Clark]

Just a quick update - I have tried setting the sensitivity to Fast and also the mid point for small perched (but moving birds) and it is too fast, the moment you lose the bird it latches onto to something else. I have not yet tried a faster sensitivity for flyers but for the time being I have set it back to slow.


It seems like the solution to this problem would be fast acquisition and then once locked, the camera switches to slow. Anyone know if that's possible? I haven't seen that described anywhere. Then it would be nice if you set the speed for the two conditions. I only see one setting in the Mark IV custom functions for AF speed.

Roger

[Roy Churchill]

It seems like the solution to this problem would be fast acquisition and then once locked, the camera switches to slow. Anyone know if that's possible? I haven't seen that described anywhere. Then it would be nice if you set the speed for the two conditions. I only see one setting in the Mark IV custom functions for AF speed.

Roger
Yep, that would be nice Roger. Out of interest I have just tried this using the Camera user settings on the 7D (C1, C2, C3) and it works so you could have fast tracking on,say, C1 and then just switch to C2 where you could have slow tracking. Trouble is you would have to change the 'C' switch while trying to keep the bird locked - very difficult I would have thought.

[Jim Neiger]

Tracking sensitivity is often mis-understood. It is actualy a delay between being focused on a subject at one distance and attempting to focus on a subject at a different distance. It has nothing to do with initial acquistion focus. Hwere is how it works and how I use it.

When tracking a bif (or other subject) and the focus point misses the bif and hits the bg, the camera will try to focus on the bg after a short delay. The length of the delay can be manipulated a little via the tracking sensitivity setting. I set TS to SLOW. This menas I have the maximum amount of time to get the focus point back on the intended subject. If the delay expires and the camera focuses on the bg, then I have the same delay (SLOW) geting the focus back to the bif. As you can see, it is a double edged sword. Sometimes it helps you and sometimes it hurts you. The good news is that you can override the TS delay. This is done by letting off the focus and re-focusing quickly. I call this bumping the focus. Overriding the tracking sensitivity is one of three uses I have found for bumping the focus. My conclusion is that setting the TS to SLOW and bumping the focus to override the TS when it is working against you is the best way to use TS. This allows you to use the maximum delay when it helps you, and no delay when it would hinder you.

[Robert Hardy]

I agree with Jim, bumping the focus and slow is TS really works well.
Rob.

[Roy Churchill]

As per my post #9 after a brief flirtation with fast and mid speed I have now reverted back to Slow - always worth trying things for yourself though. I use the AF-On button to focus and although I did not know the technical term for it I have been 'bumping' the focus for quite a while now.
Anyway Guy's thanks for the feedback it has been an interesting discussion.