NIKON AF TRACKING BIF
On my D300 if I use AF-s rather than c will the AF continue to track the original s center target even after/as I recompose and it continues to move? I could not gather that from the manual. I have a feeling not and that I would have to change focus points which seems very awkward tracking BIF.
In one of the 4 dynamic modes it will.
In single point it will not.
Thanks James. If I understand you, as long as, I am with-in the 51 point area I use to track, AF continues to track the original primary target regardless if it were acquired in the s mode or the c mode on the front switch. In other words, The Dynamic AF selection is the primary control and the s or c mode is secondary or slave to that selection.
Why Would You Use AF-S for BIF?
I don't understand why one would even want to attempt to do this?
AF-S is definitely meant for static subjects and from my experience, unless you're shooting fairly large in the frame subjects, there are far more effective AF modes than 51 point.
My usual method is to (in 51 point mode) center focus and then crop later for BIF postion in frame. IF, the front s switch (single servo) means it will continue to track the initial position with-in the 51 point AF range, would allow you to focus and recompose for a better initial composition.
Any suggestions better than 51 point tracking (tracking lock off) would be gladly appreciated.
OOPS!
AF-C tracks!!!!
Thanks James, you were my hero. At least you and Al know what kind of camera to use. ;) I really didn't think it would work - but I wasn't sure so I thought I'd ask the experts. :D
I'm surrounded by Canon users.
Canon - S = Servo
Nikon - S = Single
May you shoot straight and long - :)
Hi Bill
I agree with Jim that AF-S is very much the last option to consider (if at all) for BIF. :eek:
Most photogs (me included) appear to use the following set-up for the D300:
Another aspect to consider is having the 'AF release' in the camera’s at the default setting, so images can be obtained whenever the shutter is released. The number of times I’ve obtained sharp BIF images, even though the camera indicates nothing is in focus, is remarkably high.
- Focus Mode set to AF-C;
- AF Area Mode set to 9-point dynamic AF Point;
- Focus Point with the centre selected;
- Lock-on which controls focus tracking sensitivity is more variable as some have it switched off. Others have it set Short (my setting) or even Normal, i.e. the neutral default setting. The one setting definitely to avoid is Long. The a4 section on page 270 of the user's guide explains this custom setting affects the AF.
Cheers: Wayne
Thanks for your input Wayne. I will assume when you refer to AF-S as a last option if at all, you mean - AF-area mode single point AF selection on the back controls. My question was in regard to dynamic area AF "in single servo AF". Just how would this would function tracking rather than the other dymamic range selection c on the front - but this has been answered.
In regard AF tracking lock on in regard your comment "sensitivity", actually it has more to do with re-aqusition or lag time after losing the target and re-aquireing it, not how long it takes to initially lock up. I prefer (if you have a fairly steady hand) to leave lock "off" giving almost instantanious aquasition on your center point after you lost it for what ever the reason may be. I have missed many shots after releasing the shutter button waiting for the tracking on the last location to let go and recalculate the new distance. I would suspect that's why you use "short" and I have found "off" preferable.
Just for grins, you may want to try 51 point AF if your shooting open sky for BIF.
Wayne, James Shadle, one of the Nikon pro's here has recommended 51 point 3D with the new bodies which I am going to try.
Bill, I use the same settings as Wayne.. I find that 51pt 3D is just too much data for the CPU to process fast enough...Originally Posted by Bill McCrystyn
If you are using the front switch to select AF-S, then there is no tracking. Once the body locks on to the initial target, it will stay locked at that distance, not on the primary target.. if the primary target is a BiF, it will OOF in short order. It doesn't matter how many AF points you have activated, there is no hand-off in AF-S mode. AF-S focuses once, locks and does not refocus until you release and half press again the shutter release (or AF-On). For BiF's there is no question, you want AF-C on the front switch..
I'm not sure I agree with your interpretation of the Lock-On feature.. It isn't so much about the "re-aqusition or lag time after losing the target and re-aquireing it". It is more about how long the AF holds your primary target before reacquiring a secondary target that comes between you and the primary, and how long it holds lock on a subject that is moving "abruptly" towards or away from you..
Hi Michael, Your explaination is basically correct. I guess I was trying to say the same thing in an awkward way about the lock-on tracking feature. If it holds longer on initial aqusition that means it takes longer to release and re-focus by the same token, trust me. This has caused many problems reqardless of releasing the shutter to get a new lock. The lag time while you wait for it to drop the last lock position, not familiar with "off", is many times not acceptable. If you have problems holding steady then perhaps fast or normal tracking would work better for some.
I have always of course used AF-C but was just curious how/if the S would work in the 51 point format. In regard 3D, I haven't tried it as yet but based on one of our masters Mr Shadle I am going to give it a try. You may indeed be right. I have turned noise filtering "off" to lessen the burden on the buffer and likewise turned tracking lock to "off" to save reaquire time, and as a result, not waste possible frame counts per sec available for the burst at the moment.
Bill, the situation is the boss...
If you are shooting BiF's, or birds launching from a perch, then leaving Lock-On to off will work. If, on the other hand, you are shooting habitat shots where grass or branches might pass between you and the primary, then it's helps to set to Short or, in rare instances for me, Normal.
I guess I always looked at Lock-On relative to retaining focus lock on the primary as opposed to acquisition of a new subject. I just release the AF-On button or point at the new primary. Just a thought, and I haven't tested this, Lock-On is designed to avoid acquiring a new subject, or to hold the primary when there is "abrupt" change ins camera to subject distance... maybe if you reacquire you new target with less abrupt motion it might not hold lock on the old target.. Just a thought.
You are right - I started this thread in regard BIF. Most often than not 3D or 51 point will not work well with brush or complex backgounds. There is no one size fits all.
Michael,
"maybe if you reacquire you new target with less abrupt motion it might not hold lock on the old target.. Just a thought. "
Once again you would be correct. It takes about a half a second to "release". The problem is that a Mallard flys at about 60 MPH or a very close proxcimity subject and/or full framed subject so again lag time can be a factor in refocus and defeats my purpose.
I suspect the reason the big new Canon's useing, what, 45 point AF sensing, is to correct aside from tracking, a fast moving object with more accuracy. If you initially center focus and become lost (procede or lag behind) your subject in movement the next sensor will recalculate the distance so it senses the next best postion for better or worse. Assuming you focused on the eye if you track off at all you want to be as close to the next sensor point as possible. I find, as they do, 51 points is far better than 9. This is a big problem I had with my old 9 point Canons, amougst others. This is more important if you are concerned with using a larger aperture and shallower DOF.
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