D80 Focusing Question

Discussion in 'General Technical Discussion' started by NewBert, Aug 5, 2008.

  1. Having recently shot both horse racing and bicycle racing for the first time, I got a lot of useful feedback on the images. One of the consistent comments was that the images were out of focus. Someone suggested that I view them in ViewNX to see where the focus was.

    Well - I did that and found that a substatntial number of images had NO focal point on the image (per ViewNX). Most of these images were in the middle of a string of images shot in Burst mode, but others were not. I was using AF-C and was trying to follow fast moving horses (from the side) and not-quite-as-fast moving bikes (mostly from the front or 3/4 view).

    The lenses used were my 55-200VR (mostly) and also some with my 17-55/2.8, all handheld.

    Is this phenomena caused by poor shooting technique? Or could there be an equipment problem? Is there some kind of test that I can try to determine why some images don't have a focus point at all? I could understand having the WRONG focus point with fast-moving subjects, but why NO focus point? :confused:

    Thanks!
     
  2. With no focus point, it means the camera has not acquired focus when you've releaed the shutter. This means that your AF-C release priority is set to Release. This allows you to release the shutter even when the camera hasn't locked on focus.
     
  3. As for technique, you should use AF-C to focus on the horse before it gets to the point where you click. And follow it through at the same speed, release the shutter, and keep following it till after you get an image back in the viewfinder.
     
  4. Not sure whether I follow this completely.

    Does the D80 allow the release priority to be set to something else? If so, how and what should it be set to in this instance?
     
  5. I can't remember now tbh. If you changed AF-C release priority to Focus then it wouldn't let you release without having a focus lock, much like AF-S
     
  6. Let me try to undertand this correctly....

    Are you saying that, If I want to capture the horse at say 50 yards -- I should first acquire it at say 75 yards, hold the shutter down half-way, and then complete the shutter release at 50 yards? In AF-C, does holding the shutter down halfway lock in the focus distance or does it allow the camera to re-focus on the object (ie - the horse) as the distance between it and me changes?

    In other words, what do you mean by "follow it through at the same speed"?

    Thanks!
     
  7. ok, you'd acquire focus at 75 yards, and keep it half way, on AF-C this will cause the camera to continuously focus on your point, you then release the shutter at 50 yards (still following), and keep following it for another 25 yards after.
     
  8. Right. In AF-C keep the button half-pressed and it keeps it in continuous focus until you press full down and shoot.