There have been a couple of threads on the difficulty of focusing on a bird behind a branch.  I have not been able to respond because I have been having a knee replacement, but am now back home with (forced) time to rest and check out my experience in AF settings.  Others may have a different setup and may find something different.I am using OM-1 with PL50-200+1.4x tc (my regular walk around setup)Camera is set up with smallest (single) AF area, subject detect, S-IS auto, S priority,1/1250th, auto iso, AF area pointer is ON2 .  I don't think there is anything in my set up which is unusual.  I can expand on setup if anyone asks.Its a terrible wet day outside and no birds to see. So  I am using a flower bud 12 feet away, with a leaf 6 inches behind it as a target. The bud is about as wide as 2x the grey small AF box.  The leaf is about 7AF boxes wide.  The bud is about half the size of a bird.  The results are the same if I use a leaf in front of the bud.I am zoomed to 200mm (ie 280mm with TC)With S-AF on the budI get 100% accurate focus over multiple attempts, with the small green focus confirmation box showing in the centre of the small grey AF area box in the EVF. (the green focus confirmation box is about half the size of the AF area box)If I move the camera so that the grey AF area box is 100% on the leaf and just not touching the bud, I get 100% accurate focusing on the leaf over multiple attempts.  If I move the AF box back to the bud it is 100% perfect focus.  When the grey AF box is partly on the leaf, and partly on the bud, the camera seems to lock on the subject with the greatest area in the box.  Exactly what I would expect.That to me confirms that I can be 100% sure of getting the bird in focus if either the grey box is fully on the bird, or if most of it is.(When using 200mm +1,4TC the subject area corresponding to the grey box is very small increasing the chance that it is all on the bird)The downside is 1) that on acquisition of focus the image 'shakes' for a fraction of a second.  I can put up with that.  2) When I reframe from a distant subject to a close one, it is slow to focus and may hunt. (At least it does in the gloomy conditions today)With C-AF on the budI get 100% accurate focus over multiple attempts just like the S-AF test.However if I move the grey AF box just off the bud, it continues to focus on the bud.  I need to have it alt least 3AF squares away from the bud before it will reliably focus on the leaf.  Interestingly it initially focuses on the leaf but then changes its mind to go for the bud unless there is a significant (3 boxes or so) separation from it.  Unless the bird in the bush has a large area clear of the branch it is not going to be in focus.There is no shake on focus acquisitionMy conclusion is that for my set up, birds in bushes require S-AF for reliable focus and discrimination from branches. C-AF will be unlikely to work.Obviously from their posts others disagree and I would be very interested if they can detail their set up and tests leading to a different conclusion.  I will try them outSorry to go on a bit, as I say I am laid up with plenty of time to test things!cheerstom

You are not yet on 1.4 firmware?

epozar wrote:You are not yet on 1.4 firmware?I am on 1.4

Very helpful Tommy.I’ve been vacillating on whether to upgrade to 1.4 from 1.3..Your accurate description match’s my experience in poor light but in good light I get good focus look even close to the margins.

Brandon birder wrote:Very helpful Tommy.I’ve been vacillating on whether to upgrade to 1.4 from 1.3..Your accurate description match’s my experience in poor light but in good light I get good focus look even close to the margins.Is that using C-AF?  I will try again it tomorrow is better weathertom

Your observation is the same as mine when I did this before firmware 1.4.  I haven't compared them since.  SAF was much more likely to focus on the target, when there were any close detailed objects.  It is the opposite of the E-M1.3 where the CAF is much more likely to focus on the target in the same situation.The only thing I have tested since firmware 1.4 is focus accuracy/variability.  Firmware 1.4 reduced the focus variability resulting in a greater percentage of images with acceptable focus.

drj3 wrote:Your observation is the same as mine when I did this before firmware 1.4. I haven't compared them since. SAF was much more likely to focus on the target, when there were any close detailed objects. It is the opposite of the E-M1.3 where the CAF is much more likely to focus on the target in the same situation.The only thing I have tested since firmware 1.4 is focus accuracy/variability. Firmware 1.4 reduced the focus variability resulting in a greater percentage of images with acceptable focus.I didn't notice that, but my impression is that S-AF under 1.4 is even better at dealing with the bird behind branch situation.  Anyway it looks as though they have improved on an already good  S-AF performance.I don't understand threads saying that S-AF sucks or that C=AF is better for birds on branch (of course if the bird is hopping about a lot, C-AF might be better if you get a clear view of the subject)More experiments today from my chair looking out at my garden, but the weather is as gloomy as yesterday (typical Hong Kong Easter weather)tom