It took me years to realize what saved this image. Prepare yourself for some photo and bird geekiness as I explain.
I posted the following photo of a Northern Harrier hovering over potential prey at Bear River MBR to my blog several years ago, lamenting the fact that most of the bird was soft.
1/640, f/6.3, ISO 800, Canon 7D Mark II, Canon EF 500mm f/4L IS II USM + EF 1.4 III Extender, not baited, set up or called in
The softness was caused by a very slow shutter speed which was the result of early morning light and smoke in the air from wildfires up north. Normally I’m addicted to sharpness in my bird photos but I still liked this one and I wasn’t sure why. The head is “sharp enough” and that’s what saved the image. If the head had been as soft as the body I’d have trashed it. The tail is also reasonably sharp but the rest of the bird is soft.
I liken this shot to some waterfall or stream landscape photos that are deliberately taken at slow shutter speeds to achieve the effect of movement. It isn’t my typical style but I think it’s quite interesting and I like it more as time goes by.
So why is the head sharp (enough) and the body, wings, legs and feet are not? The reason for the wings being soft is obvious – motion blur at this very slow shutter speed but what about the rest of the bird that is soft?
The answer didn’t hit me until last night when I stumbled upon the image again and thought about it some more. The head is significantly sharper due to “gaze stabilization” (sometimes called head stabilization) in birds, especially those that are hovering over prey or hunting from an unstable perch.
Rather than try to explain it to my readers please watch this amazing video clip of a kingfisher hunting for fish from a perch moving in the breeze. I promise it’ll be worth your time.
When birds are hunting visually (or audibly or both) it’s a huge advantage to not have their head, eyes and ears bouncing around. If they can keep their head stable, even while hovering or hunting from an unstable perch, they have a significantly improved chance of zeroing in on prey for reasons that should be obvious. You may have held a pigeon in your hands and noticed this phenomenon. Even chickens do it. As a kid on the Montana farm I was endlessly fascinated by watching a chicken’s head remain absolutely still as I moved the rest of its body around in front of me with my hands.
In a way the process and results of gaze stabilization in birds are very similar to image stabilization in many of our modern cameras and lenses.
So that’s why my harrier’s head is so much sharper than the rest of its body – it was holding its head still as it hovered even though most of the rest of its body was moving more so those parts turned out soft. I think the tail is sharp because just by chance my shutter fired when it wasn’t moving. Dangling legs in a hovering harrier move a lot.
Oh, one more thing. Photographers among my readers may wonder where my active focus point was when my shutter fired. I was curious about the same thing so I used software that comes with Canon cameras (Digital Photo Professional) to find out.
My active focus point is the square in red (I had the rest of my points turned off.) As you can see I barely kept the harrier in frame and the active point wasn’t even (quite) on the bird. But if you’ve ever tested the focusing range of a single point as I have you know that it’s actually significantly larger than the point itself. So I believe I was locked on to the head of the bird or at least close to being locked.
Some might think all this is much ado about very little but I like to understand this kind of stuff about birds and about photography. It helps me to become a better bird photographer.
Ron
This is amazing.
🙂
Ron,
I like the affect and I appreciate the insight on hovering. Sometimes having a little softness is a good thing. I have a shot of a sandhill taking off at Bosque where much of the bird is soft (early morning light and slow shutter speed) and I like the soft wings and other body parts, but the head is sharp.
Its nice DPP4 provides you the information on the active AF points. That is a good thing Canon does. I miss it with my Sony gear and hopefully Sony will provide some software that shows it.
I’m going to make the assumption that the active AF point was on the birds head at some point and had drifted off a bit on this frame, but you still maintained focus. I am curious. At least in my experience with Canon and Sony, there are adjustments on how fast an active AF point will switch from one on subject to the another when it picks up something else. In some cases a slower reaction time is a good thing (for instance when you are panning with a subject and something gets in front of the subject momentarily then the subject comes back into uncluttered view (slow reaction time). I typically set up my AF to be as reactive (as possible). It would seem to me that considering the fact that your subject stayed in focus, your setup for AF is set at some rate that is intermediate. Is that the case? And also, are you using a single af point here or multiple? Probably too many words in this question, but hopefully I got the point across.
Nice shot!
Frank, I’ve seen quite a number of very interesting bird photos from Bosque where the birds, not always cranes, were soft. I liked many of them.
Yes, my AF is set at intermediate (don’t remember the official name) and if I remember correctly for this shot I had the center 5 points activated. That’s what I was doing most of the time back then.
Ron, thanks for all of the information on gaze stabilization. The Kingfisher article is very informative along with your “lesson” on the focal point. I like the photo a great deal and even better after your teachings.
I thought the article was interesting also, Alice. Thanks.
We might do the same thing, but we (or me anyway) do it a whole lot less efficiently.
Thank you as always for continuing my education.
Yes, a LOT less efficiently. Thanks, EC.
I too have always been amazed by the head stabilization in birds. It is fun to play with if you have a education bird on your arm.
I don’t think my camera lens would have focused on the bird with the focus point not being on the bird itself.
“I don’t think my camera lens would have focused on the bird with the focus point not being on the bird itself”
Don’t be too sure, April. Test it to find out. Often it will keep focus on the subject for a greater distance as you move the point away from the subject than the distance where it finally grabs onto the subject as you move it toward the bird (if that makes any sense). In other words focus lock is “stickier” moving away from the subject than towards it.
It depends on your camera settings though and some of them are pretty complicated to set up…
Interesting! A bit of info I’ll have to pay attention too! 🙂
Thanks for the active focus point demonstration. Obviously, it’s only information in retrospect, but it’s useful to know why something went right or wrong. Nikon doesn’t seem to have this software available.
“information”
Yes, but as you imply it can be very useful feedback for the future.
If you use Lightroom software I believe it’s also capable of showing active focus points on your images. I don’t use it but I think I read that somewhere.
That gaze stabilization pretty much defies all our laws of gravity and physics and always makes me giggle when I see the hawks do it while they’re on my fist. Yeah, I get the whole thing about the seven extra vertebra and all the other ways birds are superior to us and that we’ve lost most of the abilities we used to have, even though we’ve always been substandard to our feathered (and furred) counterparts. Just another reason why I like to keep them around in my life. I like to marvel at magic 😉
Just think how lucky you are to have digital photography! If it were film, well, you know! LOL!
Love the Harrier image, soft or not!
Laura, as you well know kestrels are masters at gaze stabilization. It’s truly mesmerizing to watch them do it up close through my big lens.
Yes, the video is worth watching❗️Not being a photographer I don’t notice a lot of details that your other readers see or that you talk about😕
But that’s OK I know what enjoy and it’s your beautiful pictures❗️
Thank you, Diana.
I love this shot, and part of why I do is the still head in the swirl of action. Thanks for the explanation.
Good. Thanks, Sallie.
Beautiful Harrier! Such a cool body position — amazing that he can hover like that. Every time I see one of your Harrier shots I know exactly why you chose them for your license plate. 😃
Thanks for the info and thought candy about gaze stabilization as well as the link to the article and Kingfisher video. Watching the Kingfisher reminds me of the old B&W cartoons from the 30s that have animals (and even cars!) doing the same thing, only with very exaggerated body movements. And cats — they seem to be made of rubber in the way the body can move all over with the head staying perfectly still/aligned with a visual cue. 🙀
“amazing that he can hover like that”
Not many raptors can hover as well as harriers, Marty – thus their name.
“reminds me of the old B&W cartoons from the 30s that have animals (and even cars!) doing the same thing”
I’ve been told that one of the main reasons they did that was to save the time of animators who drew the cartoons, so it also saved money for the studios who funded the cartoons.
This is why your blog is the best. Not only great photos but the most fascinating analyses along with them. Your Geekiness is very appreciated.
Thanks very much, Lyle. And I mean that. Sometimes I think I go to far with the “analyses”, in fact I’m pretty sure I do for at least some of my readers. So knowing that some readers appreciate them gives me some confidence.
Love your explanation. When I looked at the kingfisher, it was clear his head was still. When I tried to do the “gaze stabilization,” however, I couldn’t read the text while moving because of my old person glasses. “Continuous lenses” make everything close up change with any motion, at least in the extreme of mine. So no hovering over prey for me!
Also, thanks for the photo of your camera view. I have been using multiple points, but not nearly as many as you. I shall try using them all. At some point I could probably tell the lighted little square wasn’t right on the bird, and started using just a few. Clearly, the lighted square isn’t necessarily the critical one. Maybe someday you’ll tell us whether grain is a problem in some of your photos and what you do about it.
Nancy, even when we have “good eyes” we don’t stabilize our heads nearly as well as birds do. We just don’t have the muscles, the neck length or the instinct to do it well.
Usually I only use one active focus point for birds. Only in certain situations do I use more.
Grain is nearly always an issue but it’s a matter of degree from negligible to truly annoying. And the degree of the problem is aggravated when you print large. One think I do to avoid as much noise as possible is selectively sharpen the bird only since sharpening increases noise and we most often notice noise in the backgrounds of our images.
Love a hovering harrier, actually any harrier anytime, but especially when they’re closer.
When I first looked at this shot I was wondering about the soft and sharp areas, it seemed so unusual or off.
Good thing for your explanation or it might have been a very long time before I put two and two together and that’s a very valuable tip that the single focus point actually covers a larger area than the target square, very helpful and thank you for that juicy tidbit.
That kingfisher’s neck is working triple-time, just incredible!
Wonderful piece Ron.
Dave, the first time I tested the focusing range of a single point I was surprised. Knowing what I found out helped me to feel confident to use only a single focus point most of the time. In certain situations I still go back to using more than one.
Great lesson! Many thanks for the last image. I really didn’t know that the active focus point was that wide, always thought I had to be right on! Always focus for the head let the devil take the hindmost, been my motto.
Dick, It’s easy to test the range of a single point out of the lines of the square. Try it sometime. I think you might be surprised.
VERY interesting! 🙂 Logical that the head would be held still (Kingfisher in link looks like a reverse “bobble head” ) and we do the same thing! Great to be able to find out exactly where your focus point was also. Beautiful hawk by the way……. 😉 Thx “teach” 🙂
“Kingfisher in link looks like a reverse “bobble head””
I love that observation, Judy. Thank you.