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flash and double image

Discussion

9 replies
Posted by LG Price on April 27, 2006 at 11:33 PM
flash and double image
I shot the following image using a Nikon D70 with an SB600 flash. The image that resulted shows a double image. This has happened before and I am not sure why it came out with the ghost image or double. Any ideas why? :confused:

Nikon D70 70-200mmFL 1.7TC 1/500s f9. ISO500. SB600 flash. autoflash mode i-TTL. autoflash comp -1.0EV Front Curtain Mode.
Posted by Richard Wong on April 27, 2006 at 11:37 PM
That's because your shutter speed is slower than the speed at which the bird's wings are flying. The flash just happened to freeze part of it, otherwise it'd be a total unrecognize blur.
Posted by LG Price on April 28, 2006 at 7:06 AM
The Kinglet was in deep shade. I guess I thought that the flash would be enough to stop the action. Is there any way to get a stop action shot when there is not enough light to support faster shutter speeds and the maximum shutter speed that the camera uses with flash is 1/500th.

Extremely high ISOs could allow faster shutter speeds without the flash, but the quality would be low. The reduced shutter speed seems to negate using fill flash for bird shots when the bird is moving.

For the Nikon d70, there doesn't seem to be any way to use fast shutter speeds and get fill flash. I thought some people used fill flash when shooting hummingbirds. I must be missing something here.

LG
Posted by Alan Olander on April 28, 2006 at 9:27 AM
Is your exposure information coming from the EXIF data? It seems like 1/500th would have stopped the head motion. Your background is quite light making me think the shutter speed was slower than you quoted.
Posted by Rob Coomer on April 28, 2006 at 10:02 AM
Front curtain could be your problem. That means the shutter stays open longer than the flash's duration resulting in blurred or double image. Turn it off, or use manual settings. But 500th seems plenty fast enough. My flash doesn't even sync that fast.

It looks almost like you are getting some kind of reflection in the lens. If the double image is of an "eye" as I think it is, it doesn't make sense for the body to have moved that far in that length of time, but only show in the head as the movent of the wings is much less severe. From the shape of the eye, it almost looks like a mirrored reflection?
Posted by LG Price on April 28, 2006 at 5:36 PM
The shutter speed is from the EXIF data. Rob, I think you are right, it does appear to be the mirrow image. Good observation. There just seemed to be something weird about this one. Maybe it is a reflection in the lens.
Regards,
LG :wavey:
Posted by LG Price on April 28, 2006 at 5:37 PM
oh, and the reason the background is so light is that I lightened the photo considerably in Nikon Capture. LG
Posted by Bob Steele on April 28, 2006 at 5:50 PM
What I think you have here is not a relection at all (which doesn't make sense to me anyway), but simply an optical illusion. What "appears" to be an extra eye is just the motion blur and flash ghosting of the wing bar. The black an white that form the appearance of the eye are the natural colors of the wing bar. Do a 100% crop of this area and post it.
Posted by Bob Steele on April 28, 2006 at 6:22 PM
This is what the wing bar on a R-c Kinglet looks like. See what I mean?
Posted by LG Price on April 29, 2006 at 7:12 PM
here is the detail at 100%. I went back to the raw file, disabled all adjustments. You are probably right. The more I thought about the reflection, the less it made sense. I checked my flash and I had accidentally selected Backlighting which I think selects the front curtain. I turned that off. Today, when I was using flash, I changed the ISO back to 200 to try to avoid ghosts and blurs.

LG