| Joined: | Sun Apr 1st, 2012 |
| Location: | South Lakeland, UK |
| Posts: | 4066 |
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jk wrote:
I think you need to choose a different size of AF point.
Do you mean the subject size is too small for the sensors to lock onto?
That doesn't make sense, whatever the camera has locked onto is way smaller than the target, ie. it can't be too small a target.
The (AF) sensor locks onto tiny detail rather than large targets.
What I did with the D500 was follow a bird, when the bird was on the centre AF square, (or whichever was active by moving the selection with the joystick), half press shutter or press the AF lock, then the camera would follow the bird around wherever it went in the general focus area. Even if other birds came within the focus area, it stayed locked on to the original bird, and that was through double glazing and at about 50 yards. I don't know what focus 'mode' that was, I just picked up the camera, removed the silly motor drive thing from underneath and used it as was with 70-200, f2.8 and a 300, f2.8.
By locked on, I mean wherever the bird was in the general focus area, the nearest AF square would illuminate. Bear in mind this was two years ago, If I got a detail wrong don't get cross!!!
OK, I just tried this with the D3 and it behaves exactly like I described, half press on the subject, then the active square stays locked on the target within the focus sensor area.
I tried it with my D3300 and that does exactly the same. That is using '3D tracking, 11 points'. It doesn't matter where the initial active focus point is, need not be centre, you can make the active sensor point from any available. Once locked on it follows the target (subject).
With the fully auto mode the D3300 hadn't a clue what I wanted and flickered around the AF area locking onto anything which took it's fancy. I usually find If I am trying to photograph something close, like the EN-EL batteries, where I want some detail sharp, I have to repeatedly half press the shutter button until it eventually locks onto the bit I want.
For a static subject I would still use single point AF; 3D tracking is for following a moving subject. I believe on the latest bodies you can even refine the settings for smooth, predictable motion, like something which goes in straight lines or curves, or erratic, butterfly movement.
Silly as this sounds, Manual Focus and pre-setting on a fixed blade of grass, wait until the bird is in the right position, might be better for an (almost) stationary subject. This is the technique I use for motor racing, I focus on a point on the track, with the 300mm f2.8 (MF) then when the car is almost on the marker I rattle off 4 or 5 exposures, usually a couple are right on the nose, then I get to choose the exact focus point I want when I get home. I dump the others.
From what I have read, even when you HAVE mastered the AF system and got it doing what YOU want, getting that perfect eye reflection or feather detail, can mean dumping many pretty good images. But you ain't in that ballpark yet!
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Robert.