Question about shooting BIF and on perches

I'm really trying to focus on small birds in flight, but I keep getting slightly(just slightly) out of focus images. I use a 1DMKIV and 100-400V2 lens.
I am trying right now to use back button focusing, but my images keep coming out slightly out of focus, even on perched birds.
Granted I have the camera in Continuous AI focus. What I've noticed is when focused on a perched bird the camera seems to rack back and forth, If I keep the button pushed for AF and I'm wondering If this is causing the issue. Granted thats what AIFocus is supposed to do, but I'm wondering on perched birds whether its better to be shooting one shot rather tha continuous.
Any thoughts on this ?

Use AI Servo, not AI Focus. AI Focus seems to be generally regarded as unreliable, as far as I know few people use it.

For static subjects such a perched birds, using AI Servo and back button focus, just sort of "tap" the button to focus - don't hold it down continuously.

I sometimes have the same problem as you with small birds in flight. In my case it's usually because (I think) the bird is too small in the frame, not giving the camera a large enough object to accurately focus on, or I'm just not keeping a focus point on it continuously (poor technique.) Also, just select a single focus point (the center.)

Sorry I do use AI Servo, I just get them mixed up. Yes even when shooting perched birds sometime they just are slightly out of Focus. I have to find a way to shoot those little birds in flight, they are just so cool to watch !

How close are you in relation to the minimum focus distance of your lens. I can see my focus wobble a little but that's usually due to the movement of what I'm focusing on or my lens moving ever so slightly.

I would avoid one shot because you'll miss in-flight opportunities. I'm in AI Servo 100% of the time, back button focus, single focus point but I move it around trying to land on the head or eye of what I'm photographing (if it's perched) but I do not attempt to photograph the smaller birds in flight...their movements are always unpredictable.

Bsmooth wrote in post #18261443
I'm really trying to focus on small birds in flight, but I keep getting slightly(just slightly) out of focus images. I have to find a way to shoot those little birds in flight, they are just so cool to watch !

The few folks in the world who consistently get sharp images of small songbirds in flight typically use a camera set up on a tripod, and focused on a fixed distance. They either have feeding station setups or set up next to the bird's nest. They stand aside with a remote shutter release, and fire away whenever the bird comes or goes. They usually shoot wider than what they want the final image to look like, so as to increase the likelihood of getting the entire bird in the frame and also to increase the depth of field. They plan to crop the images. It's basically done the same way hummingbirds at the feeders are shot.

This method doesn't involve any autofocusing at all because they are setting the camera up to be focused to a predetermined distance.

Although it may be possible, I have never heard of anyone consistently getting sharp, excellent images of small songbirds in flight using any method other than what I have described above (except hummingbirds, of course, where the feeder setup is necessary, but the tripod and remote triggering are not always used).

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Have you checked out MFA and made sure your lens isn't slightly back/front focusing? How do you handle/hold the camera when shooting perched birds? Are you using a single AF point, or are you letting the camera choose the AF point?

I've shot the same item with lettering (a can) and every shot came out pretty well, but that was before I started to use back button focusing and AI servo on perched birds. Normally I use single shot for perched birds and AI Servo for Birds in flight.
As far as focus points I've always only used center point.

Maybe your not using a fast enough shutter speed

I tried shooting perched birds in one shot on the weekend instead of Servo ( on a 7D2 / 100-400 II ) and first impression is that I had fewer marginal focus shots and more sharp ones. Too early to be conclusive but good enough to make me want to continue this way. I have also changed the programming of some buttons to accomodate this, just need to change the muscle memory of forefinger and thumb to work them.

Thats the same thing I noticed as well. Shooting over 1/1000 on all shots, so its not blur.
I noticed on AI servo the camera or Auto focus goes constantly back and forth almost like a jitter, sometime in focus sometimes not. If you happen to click the shutter button while its just slightly off I think your getting just slightly out of focus images.
I think next week I'll still use Back button focus, but use one shot for awhile and see what results I'll get.
Back button is still a good option letting you set AF zones especially for faster smaller birds, but I want to make sure I get perched birds sharp, and so far Back button focus and AI Servo don't always give me that, problem with that is I'll have to switch to AI servo for birds in flight.

4 hours ago | #10

"I noticed on AI servo the camera or Auto focus goes constantly back and forth almost like a jitter"

It sounds like you're holding the focus button down. For a perched bird or other static subject, place the focus point on the subject and just "tap" or "jab" the button once, then let up. That should give you the same result as one-shot. For example, you can then recompose the shot, if you want, and focus won't change. If you hold the button down letting the camera continually try to focus, it will act like you're describing.

Thats the thing, I hold it down for just a moment and its out of focus, then hit it again and its in focus, even though its on the same spot. I even tried it on a tripod and it did the same thing.

tomj wrote in post #18266183
"I noticed on AI servo the camera or Auto focus goes constantly back and forth almost like a jitter"

It sounds like you're holding the focus button down. For a perched bird or other static subject, place the focus point on the subject and just "tap" or "jab" the button once, then let up. That should give you the same result as one-shot. For example, you can then recompose the shot, if you want, and focus won't change. If you hold the button down letting the camera continually try to focus, it will act like you're describing.

I hold the button down and don't let go until the photo is taken. Quite often the subject or me will move slightly while focusing, and that can spoil sharp focus. Using continuous focus guards against that.

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tomj wrote in post #18266183
It sounds like you're holding the focus button down. For a perched bird or other static subject, place the focus point on the subject and just "tap" or "jab" the button once, then let up. That should give you the same result as one-shot. For example, you can then recompose the shot, if you want, and focus won't change. If you hold the button down letting the camera continually try to focus, it will act like you're describing.

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What Tom J. says here is absolutely correct. When you use AI Servo the way he describes, it works perfectly for static subjects. If the subject is still, and one holds the back button down steadily while in AI Servo, that is what I consider to be "user error".

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Bsmooth wrote in post #18259654
I'm really trying to focus on small birds in flight, but I keep getting slightly(just slightly) out of focus images. I use a 1DMKIV and 100-400V2 lens.
I am trying right now to use back button focusing, but my images keep coming out slightly out of focus, even on perched birds.
Granted I have the camera in Continuous AI focus. What I've noticed is when focused on a perched bird the camera seems to rack back and forth, If I keep the button pushed for AF and I'm wondering If this is causing the issue. Granted thats what AIFocus is supposed to do, but I'm wondering on perched birds whether its better to be shooting one shot rather tha continuous.
Any thoughts on this ?

I'm about to make a photo shoot for my nature album for product photography sydney.

What lens do you recommend me for Portrait photography? I'm shooting some portraits and panoramics of birds.

I'm looking for some new ideas and recommendations.