Occasionally I take a photograph that seems to defy (my faulty?) logic. And when that happens I probably spend more time pondering over it than I should.
1/3200, f/9, ISO 320, Canon 7D Mark II, Canon EF 500mm f/4L IS II USM, canvas added for composition, not baited, set up or called in
This Rough-legged Hawk image is a case in point. I photographed the bird earlier this month at Farmington Bay WMA not long after it took off from a tree. I like the position of the right wing, the fanned tail, the even light on the bird and the good look at that distinctive dark “wrist” on the underside of the wing.
But every time I look at the image I wonder why the trailing edge of the right wing is so soft. At this shutter speed it must be a depth of field issue rather than motion blur but at f/9 and without the use of my teleconverter I should have ample DOF so it doesn’t make any sense to me. The tip of the right wing, the body and what we see of the left wing are all sharp and it appears to me that the trailing wing edge has to be at some intermediate distance between the right wingtip and what we see of the left wing. So how can that trailing edge be so soft?
All this made me wonder where my focus point locked onto the bird so I did a little sleuthing (any guesses where the focus point is?)
I loaded the full-frame image into Digital Photo Professional (software that comes with Canon cameras). Using DPP I can show all 65 focus points available on the Canon 7D Mark II. As usual I only had five of them active (the five I’ve marked with a blue “bull’s-eye”) and the focus point that locked onto the bird when the photo was taken is outlined in red. That explains why the wingtip is sharp but if the left wing and body are also sharp (and they are) why isn’t the trailing edge of the right wing sharp? I still don’t get it!
Many of my readers are smarter than I am when it comes to the principles and physics of photography so any insight would be appreciated.
I’m probably going to be embarrassed by an easy and obvious explanation but at least I’ll have an answer…
Ron
PS – We finally have the possibility of a few hours of light this morning so I’m going shooting. I’ll respond to any comments/questions when I get home.
Was that part of the wing fluttering as it took off? The only thing I can guess is motion. Not forward motion but motion in the feathers themselves.
Just in case all y’all might be looking for some feathered groans, Jenny Lawson has owl puns and replies on her blog today. http://thebloggess.com/2017/02/26/owl-just-apologize-in-advance/
Ron, I hope it’s OK that I posted this link. I kept thinking of this group as I read through her blog today. Feel free to delete, however. 🙂
Ok, I read all the comments and theories while I was out shooting and I’ve now read them a second time after I got home (including theories from others on Facebook). And I’m sure I’ll read them all again. I’m going to have to digest all this for a while and see what seems most plausible to me I guess. Perhaps one or more of you are correct. Some of your theories seem more plausible to me than others but for me it’s still a bit of an open question.
Whatever the actual cause for that softness I can’t thank all of you enough for taking the time to share your opinions and expertise. This process of getting feedback from folks online who really know their stuff is actually how I learned most of what I know about photography (from back in the days when I was active on Nature Photographers Network).
You guys rock!
WOW! Great shot and Great comments! I really appreciate these photographic technical aspects you produce.
However, although I do a ton of experimenting and try to figure out photographically what is going on, 90% of the time I’m mystified. Therefore, I love the fact that your fan base is willing to offer their suggestions as to what is going on! Man, what a learning opportunity!!
I’m with Laura on the “I got nuthin'” train. The parts that do the damage are clear enough for this mammal.
I’m curious about how shooting with your newly repaired 500 is going.
It is almost certainly flutter. A shutter speed of 1/3200 will freeze motion up to a frequency of about 1600Hz. If you Google ‘bird feather flutter’ you will see that the frequency can go well above that, in some cases as high as 7000Hz. I could not find anything specific to hawks, but check out this site: http://science.sciencemag.org/content/333/6048/1430.figures-only
I got nuthin’ on the camera geek stuff, but that sure is a purdy photo of a really purdy bird. However, don’t forget to factor in that raptors live to thwart us silly two-legged, funny-looking critters. 🙂
Whoa! Impressive responses. Lots of clever people working on this quandary for you Ron.
I am also interested in how close the hawk was to the camera when you took this shot.
The closer the bird, the faster you have to pan the camera, which may have an impact on sharpness.
No photogeek here, but trailing edge of wing and tail both look “soft” to me…whatever it is that ails you, it’s still a beautiful image….
Rear part of britches on right leg look soft, too…i wonder what your focus fixed on…esp. since wing looks sharp enough…
Ron, I agree that the camera settings and focus point would suggest those feathers should look sharp.
I looked at other rough legged hawk photos on the internet where the photo showed the hawk in a similar orientation to yours. Most of the time, I saw the same issue with the feathers at the trailing edge of the wing looking soft.
So I think it’s reasonable to conjecture that either they look soft naturally due to feather structure or, as Alan Kearney suggested, there could be a high frequency flutter at the trailing edge of the wing that even 1/3200 of a second would not freeze. If anyone has a photo of a non-flying rough legged hawk with its wing opened to view, that should help us decide between these two hypotheses.
Ron that software has drive me coocoo!!!!I I have given up trying to make sense of it.. my bulls eye will be on birds eye and eye will be soft or app says focus not achieved 0 af points and my image will be sharp .. I gave up !! Someone smarter than I will have to explain it to me ..
Hi Ron. Probably not the explanation here but I’ll put it on the table anyway. Considering the angle of the bird, the tip of the right wing is closest to you, and the active focus point shown in DPP4 is on that part of the bird. I would agree that 1/3200 “should” be fast enough to freeze the wing. If that’s the case, then the wingtip should be in focus. But you are saying it’s not but the rest of the bird is. The rest of the bird, so to speak, from the cameras perspective is in back of the right wingtip. So did the camera back focus off the active focal point?
From what data I have seen with fine focus computer programs, focus points do fluctuate, not hitting the actual intended point of focus all the time. For instance, if you put a camera and lens on a tripod and take 10 shots of a target, refocusing with each shot, depending on how good the focus system is, the point of focus can be in front of and behind the target. What you are hoping for is that the 10 focus spots are very close to the actual intended target so they average out to be near the target. So I think camera focusing can fluctuate and may be the case here. Better systems fluctuate the least, so they say. For instance, I have heard comments that the bundle of focus points when tested are tighter on bodies like the 1dxII and 5dIV than their respective previous bodies, indicating an improvement in focusing acuracy.
I am not saying you need to test your camera because from your post I have seem wonderfully sharp images images with you 7d II. But it’s always good to check. I’m just saying focus systems are not always accurate and multiple exposures are always better than one.
So there’s a theory you can consider. Probably as full of holes as Swiss cheese, but a theory anyway.
The tail looks soft, too. Somehow, the tail and the edge of the wing were not in the same plane as the focus. They could be closer to you or farther away. Possibly, the flight trajectory of the bird is not parallel to you or the tail is at some odd angle and matching the plane of the edge of the wing for a change in trajectory.
Thoughts from a non photographer like me might be WAAAY off.
Interesting scenario, Ron. I have a question for you here. Did you tilt or straighten the photo in the post? To me, it looks like the subject is not parallel to the camera’s focal plane. The bird looks to have tilted to the side as per the tail position and it looks to be turning to its left. If that’s so, it’s possible that the tip of the right wing is in the same plane as the body plane, for maneuverability. Considering that the Depth of Feild extends considerably towards the farther side (or back of the image plane) but not much at all towards the front, it’s possible that the front is soft.
If what I see is a full frame image, the subject is quite close to the camera, which means the Depth of Field could be too shallow as you are using a telephoto lens on a cropped body.
Interesting problem Ron. Although I don’t shoot the quality/quantity you do, I’m always perplexed by DOF.
So I did a quick calculation with a DOF app. Your Canon is considered AP-C (cropped sensor) so should have a bit more DOF than a full frame body, like Mia’s D810. Using the lens and body, but having to guess distance (no EXIF to read), at 30 feet you should have 4.25″ DOF, at 40 feet it’s 7.66″, and 50 feet 1′.07″. The DOF at 30′, only 4.25″, should have thrown the left wing out of focus, I can only guess you were farther away? I only have a 400mm on my “cropped sensor” Nikon D500 to relate to.
So, could there be some incredibly high frequency flutter at the trailing edge of the wing? A fast hummingbird would need faster than 1/3200 second, I think. That’s my guess ;-), and it’s still a great shot!
Is there perhaps some secondary motion-blur on the softer wing edge feathers as well as possible up/down movement of the tail feathers??.
Good question. I want to know why too looking at your image. I have run across this myself with similar settings. I hope someone knows the answer.
Interesting! To me the body and tip of right wing are on the same focal plane with the tail and lower part of the right wing a bit different. The only other difference I notice has to do with the color of the feathers in the areas that are soft which is much lighter than the other. A puzzle for sure!
Maybe it’s a smudge on the lens? I don’t know if that would cause it to look soft though. Hope you get it figured out!
Connie, I don’t see a “smudge” on any of my other images of the bird so I doubt it…