iTR AF on 1 Dx

[KingEyre]

Interested in opinions from 1 DX users on the forum, I've asked the question on another forum and received little feedback so thought I'd try here.

The main difference between the 5D3 and 1Dx AF systems is the intelligent tracking option (as well as the separate processor).
I wonder how many of us use this on a day to day basis, and how effective it is?
Most of the time I tend to use single point or single point with surrounding assist, which of course doesn't use this function, and wondered if I am missing using a useful function, and how/if others use it?

Thanks, George.

[MichaelGClark]

The 5D Mark III does not have the iTR system. It doesn't even have an RGB+IR light meter. The light meter in the 5D Mark III is monochrome.

The 5D Mark III has basically the same PDAF system as the 1D X, but the PDAF system must stand alone.

The iTR system leverages both the PDAF system and an RGB+IR light meter that is essentially a low resolution color CMOS sensor to track subjects using colors as well as contrast. The 1D X, 7D Mark II, 5Ds, 5Ds R, 5D MArk IV, and 1D X Mark II are the only cameras in Canon's current lineup with the iTR system.

[KingEyre]

Well I've moved on from the original post, I now use 1Dx mk2s but I still don't use the iTR sustem, however the AF on the mk2 is in my opinion, even better than the already excellent mk1 system.

[RobertTheFat]

Well, one thing that's happened in the 45 months since this thread got started is that the 5D4 has come out. How does it compare to the 5D3 with respect to the features being discussed?

[KingEyre]

Well, Bob, it's now got iTR, but I still don't know anyone using it, as I said I'm mainly wildlife and so use the centre/surrounding points usually and the iTR won't work on that.

I would say though that although the 5D4 and 1Dx mk2 have the same basic set up re AF, my experience is that the mk2 is quicker and more accurate on more shots than the mk4, perhaps due to the dedicated processor in the mk2..it's af is really excellent.

Perhaps others will comment?

George.

[MichaelGClark]

Bob,

I sometimes use it on the 7D Mark II for specific applications. It works well for some types of sports and action, airshows, birds in flight, etc. Like any new method of using the highly configurable AF systems on Canon's current upper tier bodies, it takes a bit of experimentation and practice to learn to use it effectively. Which use cases you combine it with and how you fine tune tracking sensitivity, accel/decel tracking, and AF point autoswitching will have a significant effect on how it behaves.

I think many users aren't patient enough to take the time needed to experimentally shoot with it in situations where results aren't critical (i.e. when not shooting for a paying client) to learn how to harness its capabilities. They're perfectly happy to continue to use single point or single point w/expansion as they have for several generations of camera models because it also works very well and is improved a bit from previous implementations. And that's fine as long as they are happy with the results.

For me it is just another tool in the bag. When iTR makes the most sense to me I use it. When another AF method makes more sense I'll use that one instead.

I haven't moved from the 5D Mark III to the 5D Mark IV and probably won't anytime in the near future. The two things I wish the 5D III had that it doesn't is flicker reduction and an RGB+IR meter. The 5D Mark IV has both.

Even beyond iTR, the RGB+IR meter in the 7D Mark II does a much better job at '"guessing" correctly in difficult lighting scenarios than the monchrome meter in the 5D Mark III does. Particularly in environemnts with lighting that has a fairly heavy cast on the magenta-green axis (e.g. typical stage lighting in bars and other smaller performance venues), it is much less prone to blowing out a single color channel than a monochrome meter is when the other two channels are a lot dimmer. Even though I usually use manual exposure mode in such circumstances, the meter in the 7DII can get me there faster than the meter in the 5DIII can. If I'm using both bodies I then cheat and apply the info gleaned from the 7DII to the 5DIII and shoot mostly with it!

Of course the color meter is required for iTR. I'm not sure how effective iTR would be with a camera with only a single processor instead of dual processors like the 1D X variants and the 7D Mark II. The situations that benefit the most from iTR are those that require speed from the AF system.

[MichaelGClark]

I've used it on the 7D Mark II. It works well for certain situations such as tracking athletes while allowing them to move around in the frame as the situation develops instead of having to keep them in the same part of the frame under the same AF point as the play develops. 

Prior to the 7D Mark II, which is the first body I've used with the iTR system, I never used automatic selection of focus points with any of my Canon cameras. The few times I tried it 'way back when' it seemed the AF point with the nearest subject under it was always selected resulting in photos of sharp foreground grass or gym floors with fuzzy athletes further away from the camera.

When not using iTR I manually select an AF point, usually with the four expanded points and occasionally with the eight expanded points also active. It may be the center AF point or it may be any one of the other AF points depending on the situation. It all depends on what I'm shooting. But there are times when iTR is the best strategy. It's not perfect, but no AF system is!

The ability to designate the beginning AF point when using iTR makes all of the difference when allowing the camera to change the AF point as the subject moves around in the frame. The AF point does not suddenly jump from one side of the frame to the other. It progresses around the frame with whatever it has locked onto. Unlike the old days, there isn't a tendancy to lock onto the nearest thing in the frame. The camera locks onto whatever is under the designated AF point when AF is initiated and follows it anywhere in the frame there is an active AF point. All of the AF points that can be used with the lens you have mounted are active (Group A, Group B, etc.).

Whatever choices you have made with regard to AF case, tracking sensitivity, focus/release priority etc. are still in effect with iTR.

Combined with the AF-ON button to initiate AF it is very controllable. My shutter half-press is set to only initiate metering and NOT to initiate AF. If the camera does lose tracking of the intended target I only have to let off and repush the AF-ON button to reset the AF point to the designated starting point. Of course I need to be sure the intended subject is under the designated point when I 'reboot' iTR.