Monday, July 19, 2010

More Powerful Than The Sun

We were out shooting a few shots yesterday at the Bridge of Flowers in Shelburne Falls Massachusetts. The flowers were great, as usual at this time of year, but the sky was cloudless and the sun relentless. Talk about harsh light, wow. Looking into the shade at certain spots on the bridge you could only make out the fact that there was a person there. It could have been your brother and you wouldn’t be able positively identify him in a court of law. The contrast ratio was extreme and the problems with getting a shot that was in the range of a typical DSLR’s sensor were immense. Yet, if you look at today’s image you can see a properly exposed flower and a very dark background. I’ll tell you exactly what was done in Adobe Photoshop CS5 and was as shot. The image is a crop to isolate the flower. There was a bright stick of some sort in the upper left corner. Another flower (one curl) was in the upper right corner, but it was dark enough not to be a hot spot. The color was the distraction in that case. The leaves were a touch sharper in the lower right, but that’s about it. The darkness is real. At least it is “in the camera” and not artificially darkened in Photoshop. There’s no black board or drape set behind the flower, it’s a bright sunny day, so how is it that the background went dark. Ahha! There’s actually a fairly easy way to do it. Just outshine the sun. No problem. To find out how, hit the “read more”.
As we were walking over to the Bridge of Flowers I just pointed the camera down the street, in Aperture Priority mode and read the scrolled down a couple of screens from my “normal” setting of Highlight indicating. So, now I had an average setting for the daylight falling on a general scene. It came up to about 1/400th of a second at F11. You can see that the background is three or four stops less than the flower, so a little mental gymnastics determined that a three stop drop from the general illumination would be F16 at 1/1600 of a second. Even in bright sunlight that’s a little much. Only thing left to do was to light the subject to bring it up to a “normal” exposure. I put the camera in Manual mode and dialed in F16 and 1/1600 second. I grabbed one of the Nikon SB600 Speedlites I had on my belt and fired it up. With the Speedlite held about nine inches away from the flower I started snapping away. I really didn’t have to worry a bunch about blurriness due to camera shake because of the high shutter speed. I had Depth of Field covered with the high F stop (small aperture) . Only thing left was to tame the light. 1/1600 of a second is three stops above the normal sync speed of a flash. You’d think I might get one quarter lit and three quarters black. But, I know the trick.

The “trick” is what Nikon calls “Auto FP High Speed Sync”. What it means is being able to sync your flash to any shutter speed up to the limit of the camera. Rather than one high speed burst of light, the flash goes off first, at a lower power level, and stays on during the exposure. One of the tricks of “the trick” is to get the flash in close.

Even with the flash in at nine inches, the falloff of the SB600 was a little too much. No problem again. I just whipped out a second SB600, lit it up and held both in one hand. The Nikon Creative Lighting System did its thing and perfectly exposed the flower. Zero was done to even tweak the flower in Photoshop. The exposure was spot on. Photography is light. Control the light and you get to decide the image you get. The system can do the heavy lifting as far as the mathematics goes. It’s basically a single purpose computer and doing math is what computers are good for. Learning how light works is the key to photography. Having an eye for it is where the (so called) talent comes in.

1 comments:

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