Bird detect, OM1.1

Dear fellow M43 users,

I've been having some frustration with bird detect on the OM1 (first version). This seem not to depend on autofocus mode, but let's say in S-AF and (also seems not to depend on lens) but let's say 300mm F4.

Bird detect is extraordinary good at putting a box around the bird, but focus is nevertheless often not on the bird. If there are twigs in front, focus will be often on the twigs. If the bird is on the ground, focus will often be behind the bird (but within the box).

I don't know if this is just how things work (I often turn off bird detect and put the focus point as small as possible at the center when this happens) but I'm interested in whether this is a shared experience. I'm also interested in knowing if someone understands what the camera is doing well enough to explain it (in other words, I'd like to be able to predict accurately when bird detect is unlikely to give me a good autofocus).

Thanks, Hal

As far as I understand, Subject detect is only that... it detects a subject and reports to the C-AF system where to focus, not what to focus on. If there's a failure to focus on the subject, it's because of the inability of the C-AF algorithm to differentiate what the intended subject actually is. Eye detect on the other hand is part of the AF algorithm, which is a totally different situation.

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Roger

First recommendation is never use SAF. It works much better with CAF. Bird detect works extremely well in most situations . Not where the outline is overshadowed by branches in front of it but you can't really expect anything else. In that case change the focus area to small or pinpoint.

Are you using the latest FW 1.7?

I had the same issue since I bought my camera and it has been improved with FW updates. The latest one 1.7 seems to work great for me. At least I got a lot of sharp photos during my last trip when before most would be out of focus.

Trevor Carpenter said:

First recommendation is never use SAF. It works much better with CAF. Bird detect works extremely well in most situations . Not where the outline is overshadowed by branches in front of it but you can't really expect anything else. In that case change the focus area to small or pinpoint.

Click to expand...

The other day I was following a bird and it went deep into branches so bird detect was flummoxed, but I still had a direct line on it. I grabbed the focus ring to manual focus, and from then on bird detect/CAF had no problem.

I'm using a Mark II but it's still something to remember and try.

I agree latest firmware is a bit of an improvement but I have set up my camera to instantly switch to single point which I put on the head which usually works. If the head is covered I don't bother as not worth it.

One other thing I have found is if the bird is really still the focus may jump off the bird, it as if bird detection expects movement. To counter this I use only back button focus and when focus is locked just take my thumb off the button and focus stays locked.

Subject ID basically puts the focus area on the thing that it identified as the subject. That typically works well it the target's eye is visible and there is no very close detailed contrast. However, if something is in front of the target, but relatively close and it hides the eye, focus will often fail. Also very detailed objects behind the target are sometimes interpreted as being part of the target and focus is poor.

I have a front button on both my OM1.1 and OM1.2 for subject ID, when I tap it the subject ID goes off when if it was on or goes on if ID was off. This way I can immediately switch to the small or single focus point if subject ID fails or switch back to Subject ID when it works.

If the target is moving, then CAF subject ID tends to work better in these situations, since the target is the only thing in the focus area that is constant while the foreground/background changes as the target moves.

Thanks to everyone who participated in this thread. Lots to consider checking and trying. And yes, I do have firmware 1.7; and I also have this problem with CAF, though I don’t know which is giving me better performance.

See also this roughly contemporaneous thread recommending S-AF+MF. and, like most of your replies above, the smallest focus point, which I’m already doing.


Best, Hal

It seems that the bird-detect AF in all cameras only does the most basic thing, which is "recognize the box inside which there is bird".

What a better bird-detect AF would do, would also single out the pixels that belong to the bird and not the branches and leaves obscuring the bird.

Should not be impossible to do. We will see it at some point in the near future.

tpani said:

It seems that the bird-detect AF in all cameras only does the most basic thing, which is "recognize the box inside which there is bird".

What a better bird-detect AF would do, would also single out the pixels that belong to the bird and not the branches and leaves obscuring the bird.

Should not be impossible to do. We will see it at some point in the near future.

Click to expand...

After the bird detect on my OM1.2 recognizes the box, it then focuses directly on the eye when it's clearly visible. I have no complaints whatsoever.

Perhaps some people would prefer the camera to remove the branches and leaves around the bird and replace them with appropriate feathers, but that's easily done in post these days.

drj3 said:

Subject ID basically puts the focus area on the thing that it identified as the subject. That typically works well it the target's eye is visible and there is no very close detailed contrast. However, if something is in front of the target, but relatively close and it hides the eye, focus will often fail. Also very detailed objects behind the target are sometimes interpreted as being part of the target and focus is poor.

I have a front button on both my OM1.1 and OM1.2 for subject ID, when I tap it the subject ID goes off when if it was on or goes on if ID was off. This way I can immediately switch to the small or single focus point if subject ID fails or switch back to Subject ID when it works.

Click to expand...

How does that work to immediately switch with same button the subject detect off AND switch to a small or single focus point?

I can switch subject detect on/off with an assigned button, but I'm unable to simultaneous make a small or single focus point with that button.

Also, as I understand it, for subject detection to work the AF area / box needs to encompass the subject 'detect box'. The camera can't focus on anything outside the AF area.

Lately I have my AF settings as SAF+MF and use the AF-ON BBF. For when "CAF" is needed I keep the AF-ON button depressed, and can release when I've locked focus. That focus setting and any manual focus adjustment is then not messed up when I depress the shutter.

drj3 said:

If the target is moving, then CAF subject ID tends to work better in these situations, since the target is the only thing in the focus area that is constant while the foreground/background changes as the target moves.

Click to expand...