7D MK II BIF Question

Sorry about this. I know I'm not supposed to bump. I'm sure I've been off track a few times but when your start to get into something you can over think it. Reminds me about getting over the hump about flash photography.

It first stemmed from what is the difference between switching and assisting. To me that is two distinct different things. Switching = something goes on and something else goes off. Assisting = something is on and something else comes on.

Canon says the expansion works the same in AI Servo as One Shot. One shot always shows the centre point being active. Actually you always only see the centre point when in AI Servo when viewing on the LCD or in DPP later. Based on what Canon says the expansion points in AI Servo are assist points. Even the AF point cluster is going off the target the centre point is always active working with the expansion points.

That was important to me to understand AF Switching. When you go into cases 5 and 6 (or you can do this in any case) AF switching goes from 0 to 1. This could easily be interpreted as the assist points are assisting faster because Canon does not explain this very well. According to Art Morris they don't which I still want to verify but I'm confident that is correct.

Will this make a huge difference in my photography? Probably not but I like to understand what my gear is doing.

I have recently bought a 7d MK2 - and have to admit to struggling a little. Coming from the 550D, there has been quite a learning curve - and the added paranoia of reported focusing issues hasn't helped. My camera arrived with no firmware update installed - I'm not sure if that makes it an early batch or not. Anyway, I've updated to 1.05 and have gone over various birding sites and the canon focus manuals.

I tested today primarily using case 1 for general and a mix of cases 1,2 and 5 for more type of action shots. AI servo - one point plus expansions for cases 1 and 2 - zone for case 5.

I first used my 100mm F2.8 macro and with some practice got some good sharp shots of waddling ducks etc. But as soon as I moved to birds in flight, my focusing rarely seem to lock on. I moved to my 400mm F5.6 - same problem. I've heard people mention case 2, with an adjustment to -2 for tracking - but I'm struggling. Even stationary squirrels with one focus point on the 400mm don't seem crsytal sharp to me - shutter speed minimum of 1000/1. The 550d wasn't perfect, but I nailed a few good ones from time to time.

I'm working on the assumption that this is user error. The lenses seemed sharp on the old camera, so perhaps I should look at some MF. I don't really want to shell out more money - is there something cheap/free people could recommend?

Are there any other useful reads or tips I should look at or tests to try? The reported focusing issue nags at the back of my mind - but I think that's just me getting frustrated.

Thanks

I had both 100 macro's. Seems like yours is V1 without IS but your shutter speeds should have compensated. The 400 doesn't have IS as well.

That extra megapixel count can make a difference and sometimes referred to as micro blur. I would try some really fast shutter speeds just to eliminate possible shake on your part. 1/5000. Easy to achieve on a sunny day and don't worry about noise if you have to raise the ISO. It can be corrected and you are just testing anyway.

Just curious. What aperture are you shooting the BIF?

Here is a good inexpensive MFA method to test your AF with.

https://www.youtube.co​m/watch?v=7zE50jCUPhM

The developer uses this at infinity as he finds it most accurate. Street signs, shingles on roof tops. Based on his method I have adopted Canon's minimum 50X the focal length of the lens when using it but many like to use 25X with other methods out there. Here was my target when I adjusted MFA for a 1.4 Extender. I'd use a lens you know is proven to be OK. If it was OK on several cameras without adjustment it would be better.

pgsonline wrote in post #17713438
I have recently bought a 7d MK2 - and have to admit to struggling a little. Coming from the 550D, there has been quite a learning curve - and the added paranoia of reported focusing issues hasn't helped. My camera arrived with no firmware update installed - I'm not sure if that makes it an early batch or not. Anyway, I've updated to 1.05 and have gone over various birding sites and the canon focus manuals.

Thanks

I just realized this your first post. Hello. Posting some images would be helpful.

Hi, check out the following for guides on using the 7D2 AF system. It is a HUGE evolution for even those that have been shooting with pro level camera, coming from 550D will be like going from a normal car to a jet fighter. Everything is different!

http://learn.usa.canon​.com …os7dmk2_afGuide​book.shtml

Direct link;
http://usa.canon.com …2014.pdf?WT.mc_​id=C126149

http://www.birdsasart-blog.com …at-7d-iidpp-v4-01-0-news/

http://www.canon.co.uk …eos_7d_mark_ii/​index.html

And there are lots of videos on youtube like this one;
https://www.youtube.co​m/watch?v=NpFezdEC4d4

WELCOME TO POTN!

What is the password for the guidebook.

Don't know, it's not asking me for a password?

No problem. I tried to open it a long time ago and the same thing happened. Not sure why.

I already have that one. For some reason when I click it from the site downloads and opens automatically. It asks for a password. When I opened it from the download it opens.

Minute 4:15 of the video. The video includes the 5D3, 1DX and 7D2.

It is the second last video with the Q button circled.

http://www.learn.usa.c​anon.com …birds_as_art_mo​rris.shtml

Pretty interesting. I've yet to delve into any of the adjustments within the case settings, so I just set my 5D3 as Arthur suggested. Look forward to trying it out.

He pushes everything to the max I'l have to check it out as well. I don't use case either 3 so I'll try that out too. I can flip back and forth between it and case 2 and compare.

Well if anything it confirmed my suspicions that AF switching has nothing to do with the assist points in expansion. It was never a big deal but I was searching for an answer for a long time.

%That first setting, to drop the sensitivity to the lowest setting, goes all the way back to BIF settings for the 1D and 1D2. This was to prevent the AF system jumping from the subject to the background when you let the AF points drift off the bird. The slower that setting, the longer it would wait before reacting to your mistake.

My 1D4 is still set that way. As I said, I've not gotten into any of those settings on the 5D3/7D2 yet.

digital paradise wrote in post #17713426
It first stemmed from what is the difference between switching and assisting. To me that is two distinct different things. Switching = something goes on and something else goes off. Assisting = something is on and something else comes on.

Switching is when an assisting point takes over tracking from another point. This happens in all cases where more than one point is active during Servo AF.
The difference between zone and single point with expansion is the primary point. When using expansion, the primary point is always the selected one. When using zone, the primary point is the current one.
Thus in expansion, if tracking is switched to an assisting point, the primary point remains the same. This is still true if an assisting point takes over from another switching point. But in zone there's one current, primary point and the others are assisting. As soon as a switch occurs, the new tracking point is the primary one, and the previous primary one becomes an assist point, together with the remaining points.

So, does it matter which point is primary or not? Yes, it does, at least for some cameras. I know that cameras like the 7D and 1D Mark III will always (unless this is disabled with a custom function) return to the primary point, if they are tracking with an assist point and something covers the primary point at a closer range. This can happen in expanded mode, but not in zone, since in zone the tracking and the primary point are always the same.

It's more unclear exactly what happens here with cameras like the 1DX and the 7D Mark II. The custom function to block this return to the primary point is no longer there.

This returning to the primary point is more obvious when using all points with a selected starting point (the only way to use all 61 points in servo AF when using the 1DX), since the subject can be tracked further away from the primary point than with four or eight point expansion.

Whether it is switching or assisting has never been the most important part to me. As long as an outer point is doing it's thing. The way I see it and I think you are saying the same thing is the centre point is always primary and the system will make all efforts to use it and call upon the assist points when needed when in expansion mode. Makes perfect sense to me.

When you read the manual it says single point is disabled in cases 5 and 6. The single point is not actually disabled. It will still work but you just don't get the benefit of the expansion points or zone AF points for erratic moment. Because the instructions show AF switching goes from 0 to 1 it is easy to assume that in expanded the assist points (or switch if we want to call it that) assist faster or are more sensitive. That never made any sense to me from the first day. It just seemed it was more suited for zone. I wonder how many think an AF switching adjustment effects expansion points?

So off and on I have been trying to find any documentation on it and finally I found info from Art Morris. Now we know we can shoot in 4 point or 8 point expansion in either case 2 or 5 and 6 (or any other) and get the same results as long as the TS is set the same. AF switching does not effect outer AF points in expansion mode.

That puzzled me for a long time but based on the new info it now makes sense. Case 1 is the base and cases 2 to 6 are the tweaks for various shooting situations. Experienced shooters know they can do anything case 1 but Canon set up the additional cases as basic guides.

Case 5 for example is for erratic up, down, left and right movement. By reading the instructions for case 5 (and 6) it forces a user to at least use expansion mode to get benefit of the outer points in helping track the target.

Depending on the size and speed of the target expansion may not be enough even if setting TS to -2 which gives you a bit of leeway and you can lose the target for a few seconds. Zone provides more AF points and the user has control over how fast the AF points switch.

So my set up will remain. Case 2 is the go to using single or expansion for precise tracking and cases 5 and 6 are for zone only. I'm going to experiment with some of Art Morris' settings using case 3 also because I never use it either.

I'm pretty sure I have always understood zone vs expansion. Whether they switch or not in expansion I will always consider them assist points to the centre point. Zone does not have a primary point so it does not assist anything. The system uses the AF points it needs to keep the target in focus. For semantics you can say they are assisting each other but you can adjust how fast they are doing this.

If you do set up an initial AF point in 65 point zone it deactivates and becomes part of the 65 point array when focus lock is achieved.

I may have at one point thought the assist points in expansion only assisted during the initial AF Acquisition but am convinced they are active and assisting while tracking. Sometime when you read so many articles and watch videos it can throw you off. It reminds me of when I tried to get over the hump learning about flash photography.