I have received a number of PMs and emails from folks asking me for my Mark IV settings for birds in flight. Here are my settings along with a brief explanation of why I use each setting. These settings are meant to be use dwith effective focal lengths of 400mm or longer and hand held techniques. If you want to see samples of my work, see my recent BIF posts here or in my website galleries.
1. Manual exposure mode. This is almost a requirement for BIF when you have changing bgs. There are many other reasons as well.
2. AI Servo AF - To allow AF tracking of moving subjects.
3. High speed continous drive. This allows me to shoot in controlled bursts to cature the peak action shots.
4. Center AF point only for BIF against very busy and or close varied bgs. Center AF point plus surrounding AF point expansion for BIF against distant varied bgs or BIF against smoot sky or water bgs. When a variety of bgs are possible, I use center AF point only.
5. Tracking sensitivity set to SLOW. This should be used with bump focus technique #2 below.
6. * button set to AF Lock. I use this when shooting still subjects. It allows me to remain in AI Servo AF and center AF point, but still be able to compose images of still subjects in camera. This way I am always ready for action without compromising my ability to compose images of perched birds. I use the shutter button to focus.
7. Lens focus limiter switch set to the longest near focus distance. This helps speed up AF in many situations.
Bump Focus Technique: To quickly focus or let off and refocus. There are three uses for the bump focus technique:
1. The first reason to bump the focus is to prefocus. The first task when photographing a BIF is to aquire it in the viewfinder and focus on it. It is beneficial to be able to do this as quickly as possible. When using long focal lengths, the bird may be so out of focus that you can't see it in the viewfinder even if it's there. Then when you do get it in the viewfinder it may take much longer to focus on it if the focus is set to a drastically different distance. To overcome these issues, I will prefocus at the approximate distance that I anticipate for my subject. Then when the subject arrives, I can find it and focus on it quickly. I prefocus the camera by pointing the camera at something at the desired distance and then I focus on it. Now I'm ready for a BIF at a similar distance. If I need to switch the distance I will simply point the camera at something at the new distance and bump the focus. This will prefocus the camera at the new distance. Photogs that use a tripod will often prefocus manualy. Since manual focus is difficult hand held with big glass, I use the bump to prefocus.
2. When I am tracking a BIF against a varied bg and I miss and focus on the bg I will bump the focus to quickly return focus to the bird. Bumping the focus overrides the delay set by the tracking sensitivity custom function. I set tracking sensitivity to slow to get the longest delay possible. This helps when you are focused on the bird and want to avoid focusing on the bg, but it hurts when focused on the bg and you want to return focus to the bird. Bumping the focus overrides the delay allowing you to use the long delay when it helps and override the delay entirely when it would hurt..
3. This is the most important use of the bump technique. Most photogs will aquire focus on a bif and then try to continously maintain foucs while they are tracking and watching the bif in the viewfinder. They tend to focus continuosly waiting for the moment they wish to make a photograph. Often while watching, tracking, and waiting for the moment, the photographer will miss and focus on the bg. This is extremely easy to do when the bif is flying against a varied bg. This is the reason it is so much more difficult to photograph BIF against a varied bg as opposed to smooth sky bg. When the focus grabs the bg, then the photographer needs to re-aquire focus on the bif. This may take too much time causing the photog to miss the critical moment. I try to avoid this by only focusing on the BIF when I'm sure I'm on target and during the critical moments when I'm acualy making images. So, what I will typicaly do is aquire the bif initialy and focus on it. Then I will let off the focus and just watch it in the viewfinder while tracking it visualy only. As the distance changes, the BIF will start to go out of focus. When that happens I bring it back in focus by quickly making sure the AF point is on the bird and then I bump the focus to get it in focus again. I do this repeatedly as I'm visualy tracking the bird. When the BIF gets to the spot I want to start making pictures, I will focus and shoot all at once. I shoot in short controlled bursts trying to time the critical moments with the best wing positions, etc. Because I have bumped the focus along, the focus is very close to where it needs to be when the moment to make pictures arrives. Then when I focus and trip the shutter it happens very quickly. If I tried to focus constantly while the bif approached I would likely miss, focus on the bg, and miss the critical moment. My goal is to keep the bird close to in focus and in the viewfinder without focusing on the bg and to do this up until the critical moment arrives. Then I try to maintain the focus while making great pictures. Bumping takes lots of practice, but if you develop this skill, it will make your keeper rate go way up.
I hope everyone finds this thread helpful.
Jim Neiger
