7D Auto Focus Settings

Discussion in 'Canon EOS' started by hwyblues, Oct 19, 2011.

  1. Hello:
    Every year I photograph the Bismarck Cancer Center's Hunting Dakota with Roosevelt hunting fundraising event (http://www.huntingdakotawithroosevelt.com/). I walk with the hunters and attempt to get pictures of pheasants on the fly. Although I have captured a few fairly sharp-focused shots, many are blurry because the auto focus simply does not catch the bird.
    I have experimented with different settings on the 7D to try to find the one best suited for this type of photography, but wonder if any of you have advice on the optimal settings for capturing fast and erratically moving subjects like pheasants?
    Thanks MLR
    00ZUMs-407811584.jpg
     
  2. You're talking about shooting one of the very hardest birds to capture. They can hide within a few feet of you and then suddenly jump up and fly. They seem to always be aware of the light and fly with the sun behind them whenever possible and as in your example. Further complicating things, they tend to fly low, so that your camera will try to grab focus on the background grasses and trees.
    As you walk, periodically prefocus at the distance that you might expect a pheasant. They stay down on the ground until the last possible second, so you need to keep prefocused. Put the camera in AI Servo mode Slow, to reduce the tendancy to focus on the background. Select the single-point AF pattern. You have to be certain that you've got the AF point on the bird. You shot is actually more difficult than the guys with shotguns. It's like shooting with a 22-caliber. Get on and off the shutter release button such that it's only activated (the AF function) when you're certain that the AF point is on the bird.
    This is one of the most difficult subjects that I've found. I know a place and a time that pheasant cocks fly across a road and I've spent at least 60-hours at sunrise trying to get the perfect shot of a cock flying with the sun behind me. I've gotten some good shots of birds on the ground, but still no well lit shot. They seem to read my mind. Here's my best backlight shot:
    [​IMG]
     
  3. Yep, ground birds are about the hardest subject you can find. As opposed to David, I'd advise AI servo fast with all the points enabled, but this is more of a matter of what I am used to working with. More important than the settings is simply being aware of what the camera is going to do in a certain situation and knowing how to work with its limitations. That, and a lot of luck, goes a long way.
    Keep at it, but as David has pointed out, this stuff is hard and comes down more to putting the time in (and eventually getting "lucky") than the settings on your camera.
     
  4. As noted above, try to anticipate the flight path and take a lot of pictures. Practice your manual follow focus and "trap focus" techniques. Trap focus is a term I use to describe prefocusing on a certain spot along the anticipated flight path or at a certain distance if it is against a sky background and fire the shutter in AI servo as the target approaches or flies in and out of the zone.
    While this won't help with Pheasants or Swallows, another factor for accurate AF is the lens, some are noticeably slower than others, wider apertures tend to focus faster. Having IS enabled slows them down a little bit too. IS enabled also seems to make it more difficult for the camera to stay locked on a fast moving target.
    David, that's a nice image, beautiful wing detail. I realize you're going for the backlit silhouette but I can't help imagine what a beautiful image that might make with a little fill flash, even if the wings were blurred.
     
  5. In the interest of full disclosure, like Craig, I set my AI Servo to fast. I recommended slow because that seems to be the preferred setting over at www.birdphotographers.net and Arty Morris recommends it in his books and blogs. I think that it may be the best setting for inexperienced bird photographers, but I'm not certain. I take around 3,000 clicks per month, on average and know how to "bump" the AF, so Fast works best for me.
    Knowing what the camera is going to do is most important, as Craig says. When using a tele or super-tele, there's no such thing as point and shoot. With Canon, Nikon, Sony and Pentax you'll have very similar issues when trying to shoot BIF and manage the AF.
    Oh, one other point. Shoot in bursts of three or four images. The 7D's AF is predictive and constantly correcting based on the subject's predicted movement. In almost any burst, not all the images will have equal sharpness and the later shots will tend to be sharper, IF (big if) you keep the AF point on the subject. With luck, you'll have two or three sharp images and get to pick the finalist based on wing position.
     
  6. Let's talk about "trap focus" a little bit more. I used that with my old MF Pentax Spotmatic. With a MF super-tele lens, that's about the only chance you have of capturing a ground bird in flight. OTOH, with a 7D in AI Servo mode, if you start shooting before the subject is under your AF point, the camera will start hunting for focus. If the background is blue sky, then it's search in and out over a potentially huge range, trying to find something contrasty to focus on. If the BG has trees or grass, the AF will grab onto that and it'll be tough to bring the focus back to the subject.
    I have my best success by prefocusing. If you've gotten the prefocus reasonably close, then the time it takes the camera to fine tune the focus is greatly reduced. The time difference might be .1-sec. vs. .5-sec., which is huge in this application.
    Randall, thanks. I was set up trying to catch the cocks crossing with the sun at my back. As usual, this wiley bird new where the sun was relative to me and flew with it behind him. I was facing the other way and heard the flutter of wings and the cackle of the cock as he flew and spun around to get this shot. I'm constantly amazed at how cagey these birds are. Last spring I saw one stick his head up out of the grass not ten-yards from me. I walked straight towards him and couldn't find him. They're magicians.
     
  7. David, wrt "trap focus" it's my fault for not mentioning that I also use back button focus so there are no issues with the camera trying to hunt. If anyone is trying BIF, I would highly recommend using back button focus. I too prefer a faster AF track setting, using the bump method. Another little trick I use when I anticipate the bird will be taking off toward me or on a forward tangent is adding front focus using the micro adjustment. This works particularly well on seagulls and ducks taking off in water as they tend to leap upward and forward quite a bit on takeoff, and it adds a little bit of headroom for the Af tracking system. Just remember to reset it when finished.
     
  8. David or Randall,
    Have you ever tried AF point expansion mode? I have my 7Ds set to use that, not because I have tried it and been successful with it, but because it seems logical that using 5 AF points in the center, rather than one, would increase chances of keeping one or more of the AF points on the bird. My thinking is that it SHOULD be easier to keep the 5 points covering the bird rather than the one. This of course, in my case, remains to be seen. I'm going to try it out the next chance I get.
    Also, you can easily move the AF points manually from the center to offset from center by using the grid button, then one of the dials, or use the joystick. This would work if you are constantly repeating the same shot from a set location, and you don't want the birds always perfectly centered. However, my experience here is that it doesn't matter, because it's all I can do to keep the bird in the viewfinder without clipping the wings, tail, or head. I just recompose later in post.
    Just a few thoughts.
    Sorry I don't have a recent photo of a pheasant, but here's one that I just barely kept in the viewfinder, and cropped later for better composition.
    00ZUQB-407861584.jpg
     
  9. One more thing, can you explain the "bump" method of focusing? Thanks!
     
  10. Dennis, I vary my AF points depending on the BG, size and speed of the bird. You're absolutely right, the more points you use the easier it is to keep one on the bird. For you pelican, assuming I had a second or two to switch, I would have used nine points or expanded center, but that's a large, slow moving bird and the BG is smooth and non-contrasty. Pelicans are easy to capture with single point and I'd actually go for a single-point on the head with these guys.
    OTOH, pheasants are ground birds and very sudden in their take off and tend to fly low to the ground against contrasty backgrounds.
    Back vs. shutter button AF control is a matter of personal taste. Every serious bird photographer should try both and then use the one that seems most natural to them. Once you fully depress the shutter in AI Servo mode, the AF will predictively track the subject.
    "Bumping" is bringing the camera into focus when you're certain that the subject is under your selected AF point scheme. This pelican is a great example where bumping is easy. Here's what I would have done: I see him coming and decide if he's high enough for multi-point or single point and quickly toggle to the preferred mode; next, I prefocus on a spot approximately where I'll want to bring him into focus; I track the bird in the camera without locking on AF; when he gets into the area where I might take a shot I "bump" the focus to bring him into focus then release the button and then refocus again as it gets close to keep the focus close; when he enters the shooting zone I bump focus again and then shoot bursts of three or four until he's about to pass me. If he gets to big in the frame, I focus on the head.
    Pelicans are so big and slow that I usually would simply stay on single-point. In contrast, for a mallard flying at me at the angle of the pelican above, I'd want to get on 9-point with this blue-sky BG. If they're pretty close, then I try to stop down to f/8 or even f/11 to get some DOF to increase my odds that the whole bird will be in focus. BTW, I shoot a lot at ISO 800 so that I can get the SS up over 1/1000th and still have good DOF. The 7D operates very well at ISO 800, shooting in RAW with a little +EV for most subjects.
     
  11. Oh boy....that pelican was taken with a 50D and not a 7D, plus a 70-200 f/4L IS, 176 mm, ISO 800.
     
  12. Thanks David, that's one of the clearest explanations of "bumping" I have seen for a while. Have you thought about writing a book? A lot of less experienced BiF photographers would benefit from your knowledge!
    Thanks again!
     
  13. Thank you Dennis. Yes, I've thought of writing a guide book, but my professional life has been so full of writing rebuttals to the stupid ideas coming from regulators that I don't have enough energy left to write for my own enjoyment in my time off. These little mini guides will have to fill my needs for the time being.
     
  14. Dennis- Yes, my default setting is single point expansion, though I havn't tried the nine point metohd against a clean sky-thanks David for mentioning that-I'l try mapping it to the DoF preview button for on the fly switch-overs.
    David sums everything up far better than I ever could, and as one can see from his various methods-BiF require quite a bit of thought, practice and honing for everything to become intuitive. I'd be interested in that book should it ever come to fruition.
     
  15. Gentlemen: thank you for a fascinating and informative thread.
     
  16. David,
    A suggestion if you are serious about writing a guide: find all of the thread responses you have written here (or elsewhere) and copy and paste them into a word processor on your own computer. It will be a bit disorganized and the text will be haphazard at first, but will be valuable material to draw from later, and will take less time than writing from scratch.
    Later, this will give you ideas of what to cover, and raw material to edit into shape! I have some of Arty Morris's guides, and also books by John Shaw and others, and while there is much useful information there, I don't find it particularly well organized (or current in Shaw's case). Your mission, should you decide to accept it....is write a guide that is easier to read and understand, and because of its organization, is easy to update often.
    I have often thought of rewriting some of Morris's guides, put in a T.O.C. and an index and organize it into logical topics that make sense; e.g. basic settings to things to think about while in the field. Is there a logical workflow in the field as there is in post processing (would this be a great chapter)? Then my plan would be to send the rewritten guide to him and see what he thinks. I may not be a terribly creative writer myself, but I can organize with the best of them (I'm a great editor, and I've got time since I retired recently).
     
  17. Thanks for the suggestions Dennis. I often do write the way you suggest, cobbling together pieces from related articles. I also write using stream-of-thought and take advantage of computer's ability to reorganize and structure. Also, I'm still old school enough to put together an outline for my more ambitious projects.
    I don't plan to write a book, but this is a good idea for a blog where I'm a guest writer. If I do that, I'll post a link in this thread.
     

Share This Page