This is going to be a very long (and may get sidetracked too) threads to be able to put all my thoughts down on a contained explanation and topic. Going to use lots of pictures too (all of the images have been edited extensively to beat of my skills and I preferred look to them) but going to put them behind spoilers (though data is a lot more generous available this days). Also thank you very much if you can manage to stay with me to the end of this, I really appreciate it. So I got my Olympus E-M1 Mark I almost a year ago, mainly because I had bought the Olympus 14-54mm Mark I (still have it and it’s my main landscape lens) and the Olympus 5o-2oomm Mark I (my favourite lens ever, well until a month and a half ago, also it died at the begging Of this year). I knew about the limitations of AF of Four Thirds lenses with Micro Four Thirds cameras, but I was quite content with AF-S as I started learning to do Wildlife photography and very limited for Birds. It was quite a refresh from using Manual Focus only with my Olympus E-M5 Mark II I used for a few months before, being able to focus (no pun intended) on composition, action, exposure. I have tried C-AF once in blue moon but the results were pretty disappointing so I just stuck with S-AF. But then my Olympus 5o-2oomm died (mechanical failure) and after a very long time of trying to convince myself I got the Panasonic Leica 5o-2oomm to replace it. And what a beast. So for the last 2 months I have been relearning and discovering C-AF and Tracking AF on the Olympus E-M1 Mark I. And here is what I learn: I need more learning So here we go (if anyone has tips and advices feel free to drop them and I will do my best to used them and get better at it). First, things that are not related to Continuous Autofocus but that can help get more out of it is finding wildlife, tracking their movement and be as less intrusive as possible. Finding or spotting wildlife: sounds easy, not so easy to do actually. From thick foliage to ver good camouflage it’s not always easy to spot animals in nature (unless they are really loud, like birds): Spoiler Subscribe to see EXIF info for this image (if available) From a distance the chicks were very hard to spot because they blended very well with the tree bark, even making the pictures it was needed some post editing to bring a bit more contrast and separation to see them well. Spoiler Subscribe to see EXIF info for this image (if available) I change upon a wild fox in the same place where I usually observe wild bunnies. Just for a split second I saw in my peripheral vision the foxes head before I stopped and slowly tried to get a better angle to make the picture, this is as close as I physically was able to get. After finding usual spots for specific types of animals I slow down and pay close attention to movement as well as colour shifts, like the one above. The wildlife menu I have quick access (as in my daily walk to work) to are wild bunnies, (very rare) foxes, (even more rare) deer, a plethoras of small birds as well as crows, buzzers, pigeons. One aspect I am discovering is spotting by sound (kind of duh, I know). I have permanent ear damage from a very old untreated ear infection so I have a permanent (and sometimes mentally overwhelming) ringing in my ear so most of the time I have some kind of sound playing to balance or cover the ringing (music on headphones or YouTube Podcasts or videos playing at home). But I have started to not use my headphones when I finish work and have a day off and stay around the fields and the edge of the town. Spoiler Subscribe to see EXIF info for this image (if available) I would have not been able to notice this guy if not for the loud sounds he was making out there. Tracking animals on how they move and predict where they might be or heading can be a very though challenge, especially if you don’t know the animals behaviour. Some can be predictive: Spoiler Subscribe to see EXIF info for this image (if available) This little chicks stayed clumped on the same spot for the entire hour that I was stalking them (I think to make their parents job easier to find them when bringing the food). After 10 minutes of observation I realised that they are not going anywhere as long as I don’t get to close and/or threaten them in any way. Spoiler Subscribe to see EXIF info for this image (if available) Or very unpredictable behaviour, like squirrels, as they go up and down, left and right in a matter of seconds. Observation and patience is key ... and learning from books or other sources about different animals behaviour and instincts. Getting as close as possible is a beast in itself as a skill. ALWAYS be careful and do not approach dangerous animals (duh?!?). Less harmful animals is a different matter. Because most of my early photography I did not own long lenses and manual focus only most of the time I learn early with lots of practice to move very slowly when approaching wildlife (mainly butterflies at that time). But it works with bigger animals too: Spoiler Subscribe to see EXIF info for this image (if available) Spoiler Subscribe to see EXIF info for this image (if available) Spoiler Subscribe to see EXIF info for this image (if available) Walk very slowly with slow footsteps with soles first and heels last, do not change body posture, size or shape (like raising arms to the side), keep camera close to the chest and the face so you can slowly react and make pictures. Because lenses are cylinders for animals it basically looks like a big eye is watching them, to be expected they would feel scared of being watched by a predator with 67mm eye. What may help with stability when shooting such long (or close) distances is not just the body stance/posture (don’t worry about the dirt on the knees, do go closer to the ground) is breathing. Snipers in the military learn to control well their breathing before and during taking a shot. It applies for wildlife too. Take deep and constant breaths when racking and the viewfinder will be more stable. Just before taking an image or a burst hold your breath and you can get stable enough for either slow shutter speeds or less camera shake. (I guess all those 10 years of playing Counter Strike shooter when I was a teen finally paid off , I didn’t do military service). Another point of interest is camera angle and height. Especially for birds. While birds will tend to stay up to the tree top, if you are patiently waiting for more then a few minutes the birds will go lower on the tree. The closer the birds are to your hight the more natural it feels (and less of making picture of birds butts). Spoiler Subscribe to see EXIF info for this image (if available) Same with ground level animals, the closer you are to their level the more the images look and feel like it’s a window into their world and not a look as they are being observed in an overlord fashion (am I going to overboard with metaphoric speak?). Simply put I find the closer you are to the subjects level to more engaging the picture feels. Spoiler Subscribe to see EXIF info for this image (if available) Now, what does all of this shinanigins have to do with Autofocus? Well without a good base of those above no Autofocus performance will save you when the animals are nowhere to be seen or constantly run away from you. But if you do have a good use of them you can get more out of the Autofocus performance, especially C-AF. How does Panasonic Leica 5o-2oomm and Olympus E-M1 Mark I perform? Well, confusingly. While trying to get used to C-AF I have been noticing inconsistence performance. For about 2 months I have been focusing mainly on C-AF with Tracking to see how well it works, or not, in a variety of light conditions and subjects. I will start with the most exciting opportunity and it starts with a story (yes, I am wondering how much longer does this thread drag on too): One morning, after work, I decided to stay around the grass field nearby and see what might happen (encouraged by some nice picture opportunities I had a few hours earlier). And I noticed a big bird in the sky, surveying the area like a drone: Spoiler Subscribe to see EXIF info for this image (if available) It’s a buzzard (or at least I think it is, I’m defined no biologist). So I decided to stay and watch its behaviour. So it swoops high and low until one moment it stops .... and like a helicopter it hovers, beating its big wings and keeping itself, incredibly, in one spot and was looking down, scanning very intensely bellow (never seen a bird that big do that before, and I used to watch a lot of National Geographic documentaries as a kid): Spoiler Subscribe to see EXIF info for this image (if available) Back to Autofocus, I had the camera set to C-AF with Tracking, 5 FPS anti-shock mechanical burst, 9 square AF area and centre weight metering. I keep the shutter speed as high as I could, usually1/1000 to 1/4000 of a second. It seems to catch focus on the first image of the burst but then it slowly loses focus and can’t recover unless I stop the burst and refocus: Spoiler Subscribe to see EXIF info for this image (if available) While I shot almost 2000 pictures that morning, the happy rate for me was around 25%. Most of the time the background was blue sky or grey clouds, while the subject was just the size of a single AF point. Longer lens might have helped, but a focus limited would have made it a lot quicker for the AF to recover. So when the bird was keeping a keen eye on its pray bellow it would make small dives to inch itself closer to the grass field: Spoiler Subscribe to see EXIF info for this image (if available) I wish I had use spit metering because on most of the images the bird was underexposed and even at ISO 100 shadow recovery is not looking good. Spoiler Subscribe to see EXIF info for this image (if available) When it has finally got a full lock on its pray bellow, like a guided missile it plunged so fast to the ground level at even at 10 FPS I got only one picture in the entire burst as it dived. Now comes the most disappointing part of that morning: Spoiler Subscribe to see EXIF info for this image (if available) This is the best that I could do to make a picture of where it flew off with its meal. The Tracking AF could not keep up with the bird no matter how hard I tried. While the ISO sky rocketed because of the dark trees behind and because clouds were rolling in and changing the brightness dramatically quick. This is the only picture where it was in focus enough (but it’s still to out of focus) to see the field mouse in its talons. The AF was going in and out, from minimum to infinity and while I could track the bird by shape the camera could not put the focus on the bird at all. I had tried 5 times, the bird had 5 dives about every 20 to 30 minutes (I stayed there for about 2 hours and a half). I hope I can try again soon, maybe get better luck next time. I have tried Tracking AF with still subjects and slow subjects to see how it behaves. While it does get focus on the first frame, it immediately starts flickering back and forth, up and down, left and right even if the subject doesn’t move (that was to be expected) or starts to move (meaning it didn’t track where it was moving, just where it was before). Spoiler Subscribe to see EXIF info for this image (if available) One such example, where the left bird was sitting alone on the branch, and a male showed up out of nowhere from the left side, the camera was late to “see” the new comer, it stuck with 2 frames on the new bird and it completely lost track into the background while the male and female bird were still there and on the same focal plane as before. As the male bird left the camera tried to keep the tracking on it it couldn’t keep up: Spoiler Subscribe to see EXIF info for this image (if available) Spoiler Subscribe to see EXIF info for this image (if available) I have tried to get closer to make the subject bigger in frame to the AF points have more to work with but it didn’t change anything: Spoiler Subscribe to see EXIF info for this image (if available) Most of the time I have tried using the single tiny AF point size because I have noticed the camera had a tendency to grab anything it wanted that was closer to me wishing the AF points, from tree branches to blades of grass. I will try to use AF-C only (no tracking) for the next month or so and see how that one behaves. I am sure there is a lot more I need to learn. I have not dived to much into some of the deeper menus, like the AF-C Lock settings, I left it set on Off.