Better BIFs Starts With Better Focus
I’ll be the first to admit that I’ve struggled with photographing birds in flight for years. The number one problem I and others have is focus acquisition. With birds in flight (BIFs), the ideal situation is to lock focus early while the animal is still at distance, track the approaching bird, and then capture a rapid burst of shots when the bird begins to fill the frame.
For me, my struggles have always been two-fold. First, when birds are very far away, it’s often hard for the camera to discern the difference between the subject and the background. Often times the camera will focus on the background instead of the bird. When this happens, you need to quickly re-cycle the focus system (pump the focus). The other challenge is when the bird drops below a background object such as trees or a mountain ridge. Again, the focus system can quickly lose track of the subject unless it’s fairly large in the frame.
Nikon DSLR Focus Settings For Birders
Nikon DSLRs have long offered two different focus point settings. Single-point AF is the most accurate option, because the camera focuses only on whatever the active AF point is placed on. However, with moving subjects it can be nearly impossible to keep the active focus point on the subject.
The other focus option is what Nikon calls “dynamic” AF mode. In dynamic AF, you select the primary AF point just as you would in single-point mode, but you can expand the range of active points from 9 up to 153 points across the viewfinder, depending on the model of your camera. Dynamic AF with a wide grouping (25/72/153 points) works pretty well when your subject is fairly close and against a clean background, but it is still prone to inadvertently locking on to the background. Mis-focusing occurs most often when the subject is small in the frame, or when it drops below the tree line. However, with more recent Nikon DSLRs, there’s a new and better option that has significantly boosted my keeper rate for birds in flight.
Nikon Group AF Area Mode
Beginning with the release of the Nikon D4s and D810 DSLRs, Nikon added a new AF area mode to their autofocus system. Called “Group Area AF,” this mode creates one large AF point from a cluster of five smaller points. This AF mode has some huge advantages for birders. First, you no longer need to place a single point on your subject. Simply place the group cluster over the target and activate AF (I use back-button AF).
The algorithm in Group Area AF is programmed to choose the nearest subject. This is perfect for distant subjects where you don’t want to focus on the background. On my last two birding safaris, Group Area AF worked like magic. I was able to track flying birds hand-held even when they dropped below the trees in the background. Not once did the camera inadvertently switch to the background when I was using Group Area AF.
The downside of Group Area AF is when your subject is close and you want to accurately focus on the subject’s eye, or when your subject has branches or other objects in front of it. For those situations, the “nearest object” algorithm will cause you to focus on something other than your bird. Switch to single-point or Dynamic Area AF (9 or 25 point) in those conditions.
Nikon Cameras With Group Area AF
The following Nikon DSLRs offer the new Group Area AF mode:
Thanks for this. I do have my D500 set up to use group area points (assigned to Preview button) as well as single point (BBF), but have not been using it (up until now, after reading this article) for initial focus acquisition. Normally, single point works pretty well. I had thought group area was more for *maintaining* focus, such as on a flying bird. Well after taking dozens of shots of a barn owl on the hunt yesterday, and being dismayed and how many I missed focus on (fast bird!) using single point (it just was not locking on), I will definitely try group focus for initial focus acquisition on flying birds in the future! You just helped me with a big “huh?!” moment on why I was missing shots.
I too have a Nikon D500. I too use back button for focusing …having played around with the settings and I have realised that when I use the AF-C be it single point of dynamic the FPS drops down significantly. Now whats the point of calling in a 10fps camera when in reality is shoot 5-6fps on AF-C.
Check to see what your AF-C settings are in the custom menu (A group). If it’s set to “Focus + Release” or “Release + Focus” the frame rate will drop if the AF system needs to re-acquire the subject.
Jason
Can you offer any comments yet on the D6?
I came to this camera after stints with D3, D4, D4s D850 and more recently the D6.
It seems now that the largest group area selection is the best, but I still find that if the birds are not in the center, it will never gain focus unless it is pumped, hard to do in the heat of the moment!
D6, or Z6?
I have a Nikon D500 and Nikkor 200-500 mm lens. When I am in AF-C (Auto Focus Continuous mode), even when I am taking a photo of a stationary subject, I see in the view finder the Auto Focus indicator continuously working and I hear clicks as if it is not able to lock the Auto Focus. Is this normal?
It’s not normal, but it could be caused by a variety of factors unrelated to the camera.
For example, at very large distances, thermal waves (heat waves) can cause major problems with autofocus.