Wednesday, May 23, 2007

Digital Video Cameras... a tool for documenting rare birds: Dump 'em in the swamp.

That is my conclusion after dealing with the Luneau video for the last two years, plus other circumstances where a video is the photographic evidence available. Consumer-model digital video cameras, even "good" ones, are the WRONG TOOL for documenting a rare bird record.

Some people think that a video is the best evidence, as it provides hundreds of images and shows behaviors, rather than just a few still shots. But in fact, experience is showing that a video tends to provide hundreds of lousy images that are difficult to interpret. There are two main reasons for this: Resolution and artifacts. Consumer-level digital video cameras have lower image resolution than consumer-level digital still image cameras. They typically also have more limited options for the optics needed to photograph distant birds. After these lower-resolution images are collected, they are then compressed using more "lossy" algorithms (typically MPEG) than what is used for still images. This compression step is the fatal blow. Not only does it further reduce resolution, it introduces artifacts. These artifacts especially affect edges, which wreaks havoc on interpretation of shape and field marks. Even if you are looking at a moderately good video shot, the MPEG compression is likely to mess up such things as eye color, details of bill and facial coloration, patterns of streaking/barring/scaling, etc. etc. When you are dealing with particularly bad video, the artifacts can prevent you from being able to determine the presence or absence of features that have dimensions measured in inches, not just millimeters. As an example, in the case of the Luneau video, if instead of 100 video stills, we had a handful of rapid fire frames shot with a good digital SLR at the same distance and magnification, I expect there would be no doubt or argument about the identity of the bird.

The digital video camera sounded like a good idea at the time, but experience is proving otherwise. Save it for your home movies, and instead start practicing with your still-image digital camera so you can snag useful, identifiable images of rare birds before they disappear into the woods or the sunset.


At 9:48 AM, Anonymous Dalcio Dacol said...

Hi Bill,

I don't disagree with your statements regarding the quality of the images but I think you are overlooking one useful aspect of video cameras: one can keep them recording both sound and images continuously, without a start-up delay. All still digital cameras, even if kept on all the time, will have a small time-delay before they record an image and there will be no sound recorded simultaneously. Now some of the consumer still cameras do have video capture, usually to the limit of their memory cards. But using this feature would be similar to using a video camera (but perhaps more flexible). I think the main problem with the existing videos of IBWOs is not solely due to lower quality of the images produced by camcorders versus still cameras. The main problem, seems to me, is that the operators didn't have the birds in the viewfinder when the images were recorded. Thus the images were much worse than they would otherwise have to be.


At 10:04 AM, Blogger Bill Pulliam said...

Dal --

I appreciate that aspect of video, but from what I have seen of the results (not just Luneau, and not just Ivorybills), the images that you get require so much analysis and eye-squinting that I am not convinced it really works out as a plus in the end. Getting a still camera that you can get rapid shots with, and getting skilled at doing so, still seems the better option.

At 1:27 PM, Anonymous intellectually dishonest said...

I can't agree at all, Bill. Here's a link from youtube:

If it doesn't work you can just go to youtube and search for bald eagle. This image size in this clip is very small and the whole clip is of necessarily poor quality due to the need for extreme compression. If the Bald Eagle had been considered extinct since 1940, I think this video would prove to almost everyone that they still live. You can see all the fieldmarks. The behavior is spot on, mature birds are seen interacting with immature birds, and the vocalizations are there. To me, that's all you need.

At 1:40 PM, Blogger Bill Pulliam said...

Yeah but go google for still images of "bald eagle" and look at the comparison...

The world is Ivorybill obsessed. There've been plenty of other indeterminate or crappy video rarities lately that could have been pegged much more easily with a single still than many minutes of tape. That cuban Bachman's Warbler (or is it Golden Warbler?), that inland Lesser Frigatebird, a recent Common Swift, etc...

At 3:08 PM, Anonymous intellectually dishonest said...

Those Google images aren't nearly as good as a poster size print from a large format film camera. But that's not the point. To me the point is the video only has to be good enough. It doesn't have to be perfect. The only IBWO video out there doesn't even come close to being mediocre. It's all very, very, poor. The primary reason it's poor is they're all out-of-focus shots at distant birds. Still images of those same birds with the same zoom and focus wouldn't be accepted either for the same reasons. They'd be slightly better, but not much. You'd also lose the ability to analyze flap rate, sound, movement and the like. Of course, with decent photography of any kind the ability to study those other characteristics is just a bonus.

At 3:18 PM, Blogger Bill Pulliam said...

Actually I think that, in the case of Luneau, one or two shots with a good digital camera, of the exact same scene probably would have clearly and unequivocally resolved the underwing pattern, or a white bill and dark head, or a dorsal stripe, or extensive white on the face and a dark bill, or an upperwing pattern, or etc. etc. that would have allowed everyone to agree on the identity of the bird. Sure we wouldn't have the wingbeats and flight dynamics, but we wouldn't need them to make a solid, non-controversial ID of the bird.

The big picture remains... in three years of IBWO hunting, all the photographic evidence that has been produced is video, and all of it is unsatisfying.

At 4:45 PM, Anonymous Anonymous said...

You are overlooking the Anthropic Principle, Bill.

The Luneau video exists in the worlds and time of blurry videos of Pileated Woodpeckers. It's not digital video cameras fault. They are great for bird videos!

At 4:51 PM, Blogger Bill Pulliam said...

Would that more properly be the Dryocopic or Campephic principle?

At 6:38 PM, Anonymous intellectually dishonest said...

Not to overly belabor the point, but from what I know of these videos none of them would have been taken at all if a camcorder hadn't been used. The Luneau was the result of blind luck with a running camera. Collins was just aiming in the general direction.

When good video or photos are captured it unfortunately is always clearly not Ivory-bills. I respectfully suggest that it is likely because the bird is extinct and only photography of poor enough quality is even debatable.

At 12:20 PM, Anonymous Anonymous said...

Hi Bill,

I agree with some of your points but not your basic tenet: that camcorders should be kept home.

I have owned both media for birding and there are advantages and disadvantages to each. Resolution is certainly better with stills but videos are much more "fun" to watch -- and yes, they do record behaviors, vocalizations, etc.

I agree that auto-focusing causes a lot of out-of-focus images or videos, and strongly recommend cameras or camcorders that offer EASY manual focusing.

The main problem with all existing media for the birds claimed to be IBWOs is that their quality is at best poor.

I'm not convinced that stills of the quality of Luneau's video _would_ be useful at conclusively identifying the bird to species.

Plus, no images would exist of the Luneau woodpecker had a camera been used, vs the always-on camcorder. By the time the camera was turned on (after the bird was sighted), the woodpecker probably would have been long gone.

Given the expense of 35 mm digital SLRS (bodies between $700-$2000 and lenses up to $7000 for a 600 mm Sony) vs the utterly affordable $400-500 digital point-and-shoot cameras (with 12-18 x optical zoom) or similarly-priced digital camcorders (with up to 30 x optical zoom), it's clear that most birders will be using a camcorder or a point-and-shoot when in the field. Maybe some of the Cornellians can afford to carry around $5000 camera outfits, but the rest of us can't.

There is nothing inherently wrong with using either digital point-and-shoots or camcorders, providing -- and this is what your post overlooked -- that the bird is within a reasonable distance.

For instance, if one could approach an IBWO at the distance that Singer or Tanner did, even the most inexpensive camcorder would deliver magnificent video -- in COLOR no less, the one thing that the 1930s motion pictures lack.

There would be no question as to the ID of a video of an IBWO shot within a reasonable distance (certainly within 50, even 200 feet if the view is unobstructed) using the 20-30 x capability of a consumer-quality camcorder -- perhaps even using the video feauture of point-and-shoots.

In fact, given the ability of Adobe Photoshop and similar image-editing programs to vastly alter -- create even -- images, I might guess that video will be required to confirm the presence of IBWOs. I'm sure that video can be altered, but it must be much more time-consuming and difficult (e.g., one photo vs 150 images for a 5-second video clip).

You're probably aware of the photo taken "with a Brownie camera" of a perched IBWO in Louisiana in 1971 (reproduced in _Birding_ 33: 515, December 2001). The problem with this photo, which depicts an unquestionable Ivory-billed -- is that some have suggested that it is of a stuffed IBWO specimen posed on the tree trunk (although I'm not aware of anybody with access to an IBWO specimen who would fabricate such a fraudulent photo). In this case, motion picture or video would have ruled out any question of the bird being a specimen.

Another Bill

At 12:50 PM, Blogger Bill Pulliam said...

I've got a consumer-level point-and-shoot that I keep in my pocket when birding. I have devised a simple trick of cranking out the eye cup on my right occular, holding the camera up to that, and aiming using the left occular held to my right eye. I've had no trouble getting perfectly decent shots of Pileateds, Wood Ducks, and other woodland birds on short notice with it.

In spite of the claimed advantages of the video camera, the image compression artifacts that cannot be avoided are very close to a fatal flaw in my mind. Even with the video cameras, not one single reported IBWO sighting since 2005 has been accompanied by video, even from the big woods where the volunteers were supposed to be equiped and ready at all times.

I'd be curious how many "ordinary" rarities have been submitted to review committees with video as the only photographic evidence. I suspect the still photo remains the norm.


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