5d markIII focus confirmation on viewfinder quite misleading

Initially I thought the focusing confirmation light (the round green light) would shown if focus was achieved as in 5DmkII.

Looks like I was wrong. The AF status indicator will blink followed by the focus confirmation light; in sequence regardless whether the focus was achieved or not.

I've tried it using One shot AF. The result are the same whether I choose center single focus point, spot etc( any other type of focus point except AI servo ).

Do you guys has the same experience?

I think it blinks if it thinks it's locked focus on something. Doesn't necessarily mean that focus is locked where you want it to be. Is that what you mean?

To add, the most frustating is when the blink stop and an almost permanet green light was there, it's not focus.I've set the beeper to on. At least the beeper is working.

Wonder why what have worked before they went ahead to change it?

So... are you saying your camera's not focusing at all? Not focusing well? Low keeper rates?

The AF doesn't read minds and it's not 100% perfect all the time, especially if you're not shooting things with relatively decent contrast. If it *thinks* it locked on something, you're going to get a confirmation light (even if what you wanted in focus really isn't).

Not focus at all if focus hunting to set to false or wont be able to lock a focus point if set to true.

I don't expect the AF to read my minds. If you've used the older EOS model, I believe the focus confirmations light would only stay on if it aquire a focus. Try it with the older eos camera and the 5dmkIII then you'll get my point.

I have no idea what you are talking about. My 5D3 focus light goes to solid as soon as the AF locks and focuses on something. If not in focus it blinks and the shutter doesn't release.

danielyamseng wrote in post #14608484
Not focus at all if focus hunting to set to false or wont be able to lock a focus point if set to true.

I don't expect the AF to read my minds. If you've used the older EOS model, I believe the focus confirmations light would only stay on if it aquire a focus. Try it with the older eos camera and the 5dmkIII then you'll get my point.

I don't get your point. You want your new 5D3 to function like your old EOS models?

I just tested it (now that I'm at home).

Focus confirmation light will blink if focus is not achieved. And will continue to blink with my shutter half-depressed. Never goes solid.

Focus confirmation light will stay on solid when it thinks focus has been achieved.

In AI servo, you only get the two lower corner triangles telling you focus is being attempted. If the confirmation circle lights up blinking, it means camera can't focus (i.e., violating MFD).

Seems to function fine on mine and that's how I understood it should function.

That will fail if it's under low light situation.

Probably you guys are testing it under ideal lighting. Of course it worked.

I was kinda frustated as I was on the job using it under low light and what the 5D2 has worked before the 5d3 was giving me a false indicator.

In my earlier post, I clearly stated that this situation only applies for ONE shot.

When you haven't use it under certain condition then you'd never know it'd fail.

Again, just to make it clear I'm not trying to focus on low contrast object ( common sense, I know how does AF works, just in case).

jwcdds, could you test it again if yours is showing the same symtom as mine? I just want to make sure whether it's a well known defect or just mine.

Otherwise, I'd send in to Canon for defects.

jwcdds wrote in post #14608632
I don't get your point. You want your new 5D3 to function like your old EOS models?

I just tested it (now that I'm at home).

Focus confirmation light will blink if focus is not achieved. And will continue to blink with my shutter half-depressed. Never goes solid.

Focus confirmation light will stay on solid when it thinks focus has been achieved.

In AI servo, you only get the two lower corner triangles telling you focus is being attempted. If the confirmation circle lights up blinking, it means camera can't focus (i.e., violating MFD).

Seems to function fine on mine and that's how I understood it should function.

I never shot with the 5D2 so I can't say how good/bad it was. I do have the 5Dc, though. I've shot with the 7D and I know my 5D3 can outfocus my 7D and 5Dc in low-light conditions. Where the 7D/5Dc fails to lock, the 5D3 will still achieve focus (not snappy quick, but it will lock correctly). Certainly, there will come a time when it refuses to focus. But there's only so much a camera can do.

At this point, it sounds like yours is defective, but I'll test it again when I get home. I had tried in both AI servo and one-shot.

In One-shot:
1) While camera is focusing, I only see the bottom two triangles.
2) If focus is acquired and locks, the circle lights up solid and stays lit.
3) If focus could not be achieved, the circle blinks and continues to blink for as long as I have the shutter button half-pressed.

In Servo:
1) Two lower triangles will light up during focus.
2) IF the camera is unable to focus, then the circle lights up and blinks for as long as there's nothing it can focus on and that I've got the shutter button half-pressed.

If your camera tells you it's locked on something every single time when it obviously hasn't, then sounds to me like it's defective. Hard to say what kind of lighting situation you're in though. My usual low-light situation that I should comes to be roughly: 1/200s, f/1.2, iso3200.

Julian, thanks for spending sometime to help me to confirm whether it's my unit is having a problem.
I've sent in for fixing.

But looks like this is not a common problem but probably I'm just one of the unlucky one.

The low light situation I'm facing is 1/30s,f1.2, iso25600

danielyamseng wrote in post #14624404
Julian, thanks for spending sometime to help me to confirm whether it's my unit is having a problem.
I've sent in for fixing.

But looks like this is not a common problem but probably I'm just one of the unlucky one.

The low light situation I'm facing is 1/30s,f1.2, iso25600

That might be just below the spec of the 5D3 in terms of its AF range - check what this light level is in EV at ISO 100 and compare with the specs. (EV -2 to 18)
(Aren't you at EV -3 or so?)

danielyamseng wrote in post #14624404
The low light situation I'm facing is 1/30s,f1.2, iso25600

I can't imagine how little light there is in a situation where this is required. First of all at f1.2 your depth of field is very small. Can you post a sample image of the situation. I think you're expecting way too much from the AF system.

On a side note, you're likely the first person on the planet to think that the 5DMII had better focusing that the 5DMarkIII

Yea... you are shooting in the dark. I wouldn't expect it to af at all.

This is why in dark areas i just enable the focus beep

Please read the line. I'm not expecting it to AF.

ender78, same goes to you.

The main culprit is the 5DIII misleading focus confirmation light in which it give false sense of focus lock.

5DII won't be having the same behavior, got it?

BTW, Canon are working my unit and told me they'd fix it.