Rich Ditch's Photography Blog

October 5, 2011

On the (negative) Edge

Filed under: Birds, Boyce Thompson Arboretum, favorite places, light, technique — richditch @ 1:50 pm
Anna's Hummingbird

Anna's Hummingbird

Anna’s Hummingbird, Nikon D300, Nikkor 300/2.8 AF-S plus TC20E (2x), 9/30/2011, ISO 400, 1/60th second @ f/10, remote flash

I’ve had some questions elsewhere about the “weird” look of the water in the image of a Warbling Vireo as seen in my previous post. The water appears to float in space and the vireo appears to be walking on the water’s surface. The explanation is simple – this is a so-called “negative edge” water feature, where the water bubbles up in the center of a shallow bowl and flows over the edge of the bowl to get collected and recirculated. This photo of an Anna’s Hummingbird shows the edge of the bowl with the water running over it while the hummingbird perches on the very edge.

There are two of these water features now at the Boyce Thompson Arboretum where both of today’s images were made. I’ve only recently started shooting at the newest (seen here) as it has only recently started attracting birds.

Orange-crowned Warbler

Orange-crowned Warbler

Orange-crowned Warbler, Nikon D300, Nikkor 300/2.8 AF-S plus TC20E (2x), 9/24/2011, ISO 800, 1/50th second @ f/5.6

This Orange-crowned Warbler landed on the distant side of the bowl (as most birds do when they visit), so the image shows off the curve of the bowl. And, it shows off the “floating” look.

As I’ve written here many times I prefer using natural light whenever possible. That’s what I’ve done with the warbler. In this shaded location (plus early morning) I needed to use ISO 800 just to squeak out 1/50th second for a shutter speed with the lens wide open at effective f/5.6. That results in very little depth of field, so with the focus on the warbler’s face the belly, feet and tail are out of focus. At such a low shutter speed the camera and lens must be firmly supported – I use a Gitzo carbon fibre tripod with massive ball head and gimbal mount. I still need to catch the bird at just the right moment when it isn’t moving, and that means patience, taking lots of shots, and editing out all the ones where slight movement makes the image unusable.

With the hummingbird I tried mounting my Nikon SB-800 flash on a second tripod placed near the water feature, triggered by the built-in flash on the D300. Nikon makes this easy by building in a Remote/Commander wireless flash mode that is controlled from the camera body. I should have set a lower power setting for the remote flash as I feel it is a bit bright and unnatural. I would have done more experimenting with settings if there was more bird activity on this visit, and if another park visitor hadn’t decided that the water feature made a great place for her terrier to drink and splash around in. I was too astonished by her rude behavior to grab a shot as I sat behind my camera 10-12 feet from the water as she walked over in front of me so her dog could play.

The older negative edge water feature at Boyce can be seen in some of the images in this older post on Arizona Goldfinches.


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