East Wind Photography said:candc said:East Wind Photography said:GraFax said:East Wind Photography said:GraFax said:Here are a couple of test pics to illustrate. Once I had focused on the background, not locked on just focused and released, zone AF refuse to focus on the depth gauge in the foreground as long as any of the 15 points could see the background. Since the gauge wasn't big enough in this angle to cover all of the points. No matter how much I panned the camera horizontally, the 7D2 always chose whichever AF point fell on the background. As I panned back and forth it completely ignored the 9-12 points which would have focused on the gauge.
Repeated this a dozen or so times using all of the different AF and tracking modes. Totally consistent. However, if you fire the shutter without AF ON, it releases the lock. Point it back at the scene and it will instantly lock on the gauge instead of the background. So basically its retaining it focus lock, even when you aren't focusing if that makes sense.
Even if you manually de-focus the lens it jumps right back to the background. Imagine that the depth gauge is a sideline coach and you can see the benefit of this to sports shooters.
The cormorant was probably operator error. But it did peak my interest and I'm glad I took a look at this.
Ok...looks like iTR has a role in zone AF. Manual page 128. Might actually explain not only the zone AF issue but the AF lock lag as I have iTR enabled. This was introduced from the 1dx in this model. According to the documentation when iTR is disabled zone, expanded zone, and 65 point AF will only be based on AF data, not colors, faces and other information...I assume infrared data as well...which is one feature of this new sensor.
More testing in order...
Good call on iTR having a role. That would be great because you could then turn it on and off as circumstances dictate. Adds a whole new dimension, outside of facial recognition, I hadn't considered.
I assumed that it was off by default and that I had to turn it on. I hadn't planned to use iTR until I had other aspects of the AF squared away. I think is slows down the frame rate to that means the 7D2 is even faster then I though. Awesome.
Seems like that could definitely play a role in what I was seeing today. Holding focus on a sort of uniformly lit and colored background vs the post. If that's what was causing what I saw today, I have to say that it really is impressive. I could not get it to drop focus as long as even one AF point could see those trees in the background. The plot thickens. Can't get out again for a few days but when I can I'll go back to the same spot and see if iTR makes a difference. Super.
Well I'm finding that iTR does not have much of a role in the Zone AF issue. I ran some tests in the house and found that when iTR is off it sometimes still has difficulty locking on a foreground object. I would even go as far as saying that even when initial AF has locked on the closer object, AF can switch to the background and hunt around a bit trying to figure itself out. I had this happen with 3 different lenses. With iTR enabled the same things were happening. This is clearly not how it is described in the user manual. Could be useful for some situations but I'd rather it be consistent than questionable. Questionable only makes me want to use that mode less.
I ran the same AF tests with my 5DIII using the same lenses and zone AF just locks on the closest object and stays there. Nothing in the background can make it change focus. I will strike this up as a firmware bug, do more tests outside on a sunny day and see if the condition also remains with more EV.
I have been doing some bif shooting the last couple days below a dam, giving the camera a good shakedown and seeing what works best. I also tried turning itr on and off using zone af and I don't see a difference, if anything it works better with it on. it tracks really well but doesn't always lock on to the closest thing. Sometimes if I would press and release af-on a couple times it will lock on to what I want it to but there is an issue with it not just doing it right the first time. I think there is a setting to make it prioririze a particular af start point with zone af, maybe you could try clearing that preference?
Based one everything that I have found on it so far Zone AF is not suppose to prioritize based on a starting AF point. There is none to start with in that mode. It's supposed to start on the closest thing it can focus on within the selected zone and stay there. Thats supposed to be the priority and what makes it different from the rest of the modes. iTR should really do the same but then use faces color and IR to track the object it selected to focus on.
True. It is on auto by default but maybe setting it to something else then resetting it to auto might clear something that is screwed up in the memory?
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