focusing

[lynniepooh]

The following comes from the wildlife guide for Z8/9.

"On the other hand, if you’re using the Wide AF areas for wildlife action, then it seems like having the subject occupying at least 50% of the AF area works best (honestly, if the ONLY thing the Wide AF area sees is the animal, that works best). Also, it helps tremendously to start with your focus distance either on or a bit in front of the subject rather than behind it."

My question is, how do you focus on something that isn't there? A bit in front?
Thanks
Lynn

 

[Patrick M]

If you’re testing, then you can easily use a static subject…like branches of a tree.
if you’re in the field, then focus on where you think your subject will be. Remember that you can save and later recall a focus position.

edit: the “beauty” of saving focus positions is that you can save more than one. In my garden I have two feeders at different distances to where I sit…so I assign fn1 and fn2, so I can instantly go to a feeder and be at the correct focus.

 

[DRwyoming]

The following comes from the wildlife guide for Z8/9.

"On the other hand, if you’re using the Wide AF areas for wildlife action, then it seems like having the subject occupying at least 50% of the AF area works best (honestly, if the ONLY thing the Wide AF area sees is the animal, that works best). Also, it helps tremendously to start with your focus distance either on or a bit in front of the subject rather than behind it."

My question is, how do you focus on something that isn't there? A bit in front?
Thanks
Lynn

If I expect subject at approximately a certain distance I’ll often manually focus to about that distance or autofocus on some object at about that distance. Or as written above if possible I’ll focus manually or automatically on something a touch closer.

For instance when photographing small song birds that are frequently flitting to a certain perching branch such as near a feeder I’ll quickly focus on the branch where I’ve seen them land before and then use the manual focus ring on the lens to adjust the focus in maybe an inch closer. Then when a small skittish bird like a Chickadee lands I hit the AF and try to capture some images quickly before it flies off. Having the focus preset to slightly closer than I expect the bird’s eye to be tends to allow the AF system to grab focus much faster than hunting across the whole focus range or having to pull the focus in closer from a more distant pre focus distance.

Other examples include birds repeatedly flying from a specific direction like Swallows feeding on bugs along a stream or canal or Osprey frequently returning to a nest with fish or nesting materials. I’ll watch the behavior for a while and try to pick a fixed object at roughly the distance where I think I can reliably acquire focus (meaning the bird will be large enough in the viewfinder or AF area but not filling the entire frame) and pre focus the lens at roughly that distance either manually or by shifting the lens a bit and auto focusing on a bush, tree, some grass or something else at roughly that distance before swinging the lens up and waiting for a subject to fly towards me along that route.

If a lot of subjects are frequently flying along relatively repeated paths I’ll often use the memory recall function on long lenses with that feature to quickly reset my pre focus distance to roughly where I hope to acquire focus on the fast moving subjects. This is really helpful for super fast subjects like Swallows feeding on an insect hatch when many of them are repeatedly flying along somewhat similar paths but it works for many fast moving subjects if you have some idea of the path they’ll follow which generally means some kind of feeding or nesting behavior.

Prefocusing really helps the AF system so I do it when possible and it helps even more to pre focus just a touch closer as in inches or feet closer than you actually expect the subjects to appear depending on how far away that is.

It of course doesn’t work for completely random surprise shots where you just suddenly see an animal at an arbitrary distance but can help a ton for action shots where you have some behavioral clues as to where you might pre focus prior to the action.

 

[Steve]

I was going to answer, but Dave said it all - and more!

 

[bleirer]

I think a lot of folks have the habit of prefocusing on the ground just to get the focus in front of the subject. Seems like Mirrorless needs this more than dslr did.