[tduell]

I've been getting some very poor results from my BIF shots of late with the K-3 Mark III.
I've been shooting with the DFA 150-450 with and without the 1.4x TC.
The problems have shown up when shooting Eagles and the camera/lens is close to vertical. Almost all of the shots have have very poor focus.
Some of these Eagle shots have had a shutter speed of 1/1600s, whilst other shots of other subjects with the camera/lens almost horizontal have been pin sharp with a shutter speed of only 1/250s.
I have been using SR set to 'auto'.
My AF settings have been AF-C, 1st frame action 'Focus Priority', Action in AF-C 'Focus Priority', AF point tracking 'Type 1', AF hold 'OFF'.
I've been using expanded area AF (L).
It seems to me that with an Eagle filling about 2/3 of the frame against a clear sky, the AF shouldn't have too many issues.
I have noticed that it is more difficult for me to keep the subject steady in the frame when shooting almost vertically up, i.e. more shake than usual.
The focal length has been around 300mm, so not quite as challenging for the SR as if it would be at 630mm.
Using this lens for similar subjects in a similar manner with the K-3 II never gave such poor results. With that body I almost always used AF-C with spot focus.
I've probably got a bit of experimenting to do to see if I can find a solution, but thought it would be worthwhile getting some advice and thoughts before I get too far into that.
So, let's know what you make of this, and what settings you have been successfully using for similar BIF shooting.

Cheers,
Terry

[biz-engineer]

Looks like the focus limiter was accidentally engaged. Remains the question, if the bird photographed from below was in focus, would it still be a good photo worth being printed? If not, then delete.

[kypfer]

I use AF 'zone' rather than AF(L), it seems to be more reliable when dealing with birds in flight that are reasonably close.
There's movement in multiple directions with a big bird flapping, wings up and down whilst the whole thing is flying forwards, makes for hard work for the camera.
The extra shake certainly won't help!
I'd try AF-S and spot a/f. If the percentage of correct exposures goes up (albeit the overall number of shots may reduce) then it's likely to be a technique problem. If the focussing issues continue then maybe your lens has become a bit stiff
The K-3iii can (almost) be it's own worst enemy. With so many configurable features it does take time to find the best combination for any one person and any one set of circumstances.
Fortunately, judicious use of the SFn wheel and maybe a few custom User Modes can allow multiple configurations to be tried "on the fly".
I have my SFn wheel set for AF-S 'spot', AF-C 'spot' and AF-C 'zone' and regularly flip between them with the camera to my eye.
I'm even getting used to adjusting the over/under exposure with the +/- button using just the viewfinder.
The K-3iii really is an ergonomic delight, but there is a learning curve
Enjoy

That lens has a pernicious tendency to "creep". The barrel moves in and out with the pull of gravity, so if you've got it all the way out to 450 and elevate the lens, it's going to pull back, even if ever so slightly and slowly, which means the focus may change somewhat. In my experience, the focus doesn't change very much when you zoom in and out, but it does change. If I'm going to be doing that kind of stuff with that lens, I stick a rubber band on the barrel (all the way down to the camera end of the thing) to keep it from sliding in.

[beholder3]

The problems have shown up when shooting Eagles and the camera/lens is close to vertical.
I have been using SR set to 'auto'.
It seems to me that with an Eagle filling about 2/3 of the frame against a clear sky, the AF shouldn't have too many issues.
The focal length has been around 300mm

BIF to me means a flying bird. = fast moving subject --> Not completely turning off any form of IS is a complete mistake (even though often enough the software will try to help and switch it off for you). I'd first eliminate this user error and retry.

With the stated variables you are standing directly under a flying eagle which is flying very, very low at around 15-18 m altitude. I'd be surprised if the eagle was not causing a very rapid change of your shooting angle.

Generally for these types of threads, the minimum requirement is to have a non-metadata-crippled image file showing the complete scene.
That would allow for solid analysis instead of guessing.

[ncallender]

I would turn off SR as well and really work on steady holding technique. You can't raise the shutter speed high enough to compensate for an unsteady very long focal length. I also think a smaller focus area might help.

I got really out of focus or shakey images the other day. Panning with a flock of geese. All images blurry. Turned of and on the camera and tried again. No problem at all. Do not know what happened...

[pschlute]

Some of these Eagle shots have had a shutter speed of 1/1600s

SR will not even begin to kick in at that speed

SR will not even begin to kick in at that speed

When does SR "kick in"? Does it not work all the time?

[pschlute]

When does SR "kick in"? Does it not work all the time?

With a 300mm lens at 1/1600s SR has no effect.

[tduell]

Looks like the focus limiter was accidentally engaged. Remains the question, if the bird photographed from below was in focus, would it still be a good photo worth being printed? If not, then delete.

The focus limiter is almost always set on '6m-inf', which is OK for this sort of shot. The subject would have been at least 20-30m away.
Shots of these birds are almost always from below, there aren't many other options.

Cheers,
Terry

With a 300mm lens at 1/1600s SR has no effect.

Just curious what you base that on.

[pschlute]

Just curious what you base that on.

I base it on the fact that at 1/1600s your shaky hands are not shaky enough

The purpose of SR is to enable you to use a slower shutter speed than you would normally on a camera without SR. Using a 300mm lens at speeds of 1/500s and faster do not have shake...so no need for SR

[tduell]

I use AF 'zone' rather than AF(L), it seems to be more reliable when dealing with birds in flight that are reasonably close.
There's movement in multiple directions with a big bird flapping, wings up and down whilst the whole thing is flying forwards, makes for hard work for the camera.
The extra shake certainly won't help!

No flapping, these birds just hover and glide on the wind, often an almost static subject.

I'd try AF-S and spot a/f. If the percentage of correct exposures goes up (albeit the overall number of shots may reduce) then it's likely to be a technique problem.

Yes, spot AF is on my list to try.

Cheers,
Terry

---------- Post added 08-28-21 at 03:59 PM ----------

That lens has a pernicious tendency to "creep". The barrel moves in and out with the pull of gravity, so if you've got it all the way out to 450 and elevate the lens, it's going to pull back, even if ever so slightly and slowly, which means the focus may change somewhat. In my experience, the focus doesn't change very much when you zoom in and out, but it does change. If I'm going to be doing that kind of stuff with that lens, I stick a rubber band on the barrel (all the way down to the camera end of the thing) to keep it from sliding in.

I don't think that's my problem. I've been using this lens for a long time and my technique is to hold the zoom ring with my left hand. I don't think I've ever encountered any creep with this method of support.

Cheers,
Terry

---------- Post added 08-28-21 at 04:07 PM ----------

BIF to me means a flying bird. = fast moving subject --> Not completely turning off any form of IS is a complete mistake (even though often enough the software will try to help and switch it off for you). I'd first eliminate this user error and retry.

No, not flying fast. Much of the time these birds just glide on the thermals of simply hover, but they can move fast when they go into shallow glide. During the shooting I described the bird was quite slow moving.
I think I'll try turning SR off, if I can get a suitably high shutter speed.

With the stated variables you are standing directly under a flying eagle which is flying very, very low at around 15-18 m altitude. I'd be surprised if the eagle was not causing a very rapid change of your shooting angle.

Shooting angle wasn't changing too fast, but even if it was I'd still expect the AF to get part of the subject in focus.

Cheers,
Terry

[bobbotron]

Turn off SR, up the ISO or use shutter priority to keep your exposures at 1/2000, at least while you sort out of it's a focus/technique issue. 1/250 is too short a shutter for moving birds in my opinion. The SR won't fix if your subject has motion blur.