Silver Eyes
I've been practicing with my Better Beamer as fill flash and am having the darndest time avoiding silver eyes on my underexposed victims. (most with Canon 7D, Canon 400 f/5.6, Canon 430EX). I'm probably overlooking something stupid, but can anyone suggest what I am doing wrong? Thanks :) I'm working tonight or I'd post an example.
Last edited by Ian Cassell; 10-26-2010 at 09:30 PM.
Please give us examples of your victims...birds or mammals?
I just got a new flash and a Better Beamer myself and had the same issue. Looking forward to what the experts say!
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You need to get the better beamer higher above the center line of the lens. If you are using the flash directly on the camera I would recommend that you use a flash bracket that will attach to the plate on the lens foot and get an extension bar that will raise the flash/beamer. Also there may be an issue of the beamer extending too far beyond the front of the 400 f5.6.
jim
Thanks, Jim, I'll try getting it up a bit. From parallax, however, I can't see why a few inches above camera level are going to make a big difference that far away from the lens. It doesn't extend that far forward. Again, however, why would that give my birds silver eyes?
There are a lot of folks here with the 400 f/5.6. I'd be curious to know their experiences.
"I can't see why a few inches above camera level are going to make a big difference that far away from the lens".
It makes ALL the difference. I use the original Wimberley gimbal head with their flash bracket and a better beamer and have never had a case of "steel eye". Put the flash in the hot shoe and you'll get it most of the time.
Hmmm ... Thanks, Doug. About how far above the camera does the bracket elevate the flash?
The silver/white eye effect is a reflection off the retina of the bird's eye; the same thing as red eye in people images. To get this reflection, the angle from the flash to the lens as viewed by the subject's eye must be smaller than X degrees. X is a small angle and will vary depending on the pupil size. So moving the flash further from the camera (it does not matter if above or to the side) will reduce the effect and if a large enough angle will completely stop the reflection. The longer the focal length and the further the subject is away, the smaller the angle between the flash and camera as viewed by the subject, so with longer lenses one needs to move the flash further away. I have had the silver/white eye with 500 mm and the flash on a Wimberly flash bracket after sunset when pupils are quite wide open.
The reflection in people's eyes are due to the red blood veins in the eye. So why not the same in birds?
Roger
So, birds have silver blood? :)Originally Posted by Roger Clark
Thanks, Roger. I figured it was a similar effect to red-eye. This was happening to me at dawn when it was quite dark. I do most of my shooting handheld with my 400, so I'm going to figure out some way to mount the flash off-camera (I have a stroboframe bracket, but it doesn't add that much distance and would also be clumsy with a long lens).
Since the effect depends some on the size of the pupil, the "Red-eye reduction" that many cameras have fires pre-flashes in attempt to reduce the pupil size just before the shot is taken.
Chris
0 .· ` ' / ·. 100
I have a high sarcasm rate. Deal with it.
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I can confirm Chris' statement. I've used that technique photographing Owls.
Here is another little trick. Rather mounting the flash over the lens' center-line, turn the flash bracket around so the flash is of to the left or right of the lens. Swivel the flash head to correct for the parallax (aim it at your subject).
Now the flash is off axis enough to improve or eliminate red eye/steel eye but not enough to affect the way you want to light your subject.
Hmmm ...
OK, since I usually handhold my 400, I think I will make an extension bracket to screw into the tripod mount. I wonder how far off-axis I need to get the flash. I'll look up the dimensions of the Wimberly.
Thanks.
Check out the flash extensions for really right stuff to elevate the flash since you are hand holding
Thanks, will-do.
I just saw the price on Wimberly extensions and almost died! A lateral extension would be really easy to make and cost pennies, so if the RRS piece is pricey, I'll probably try my own first.
EDIT:
OMG, RRS is even more expensive than Wimberly! I don't get it -- what makes these so expensive?
Also, looking at the pictures, do these really get the flash any further off-axis than the on-camera hot-shoe? It seems that they move the flash down the lens to the collar, but the pictures don't look like it is actually any further off-axis.
Last edited by Ian Cassell; 11-01-2010 at 06:24 PM.
I made an extension out of a piece of 1/4" aluminum from hardware store. Drill and tap a couple holes, bend to angle needed in a vise. It's not pretty and doesn't match but it works just fine.
Chris
0 .· ` ' / ·. 100
I have a high sarcasm rate. Deal with it.
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"Steel Eye" Demonstration
The retroreflection from eyes is quite narrowly focused. As Roger described so well above, the angle varies with pupil dilation. If you want to see steel eye in action, take a small flashlight and shine it at a (friendly) dog about 30 feet away in the dark. You will find that the eyes will appear to reflect brightly when you hold the flashlight shining from in front of your face, but the effect will virtually disappear when you raise the light slightly higher or lower (but still directed at the dog). The same will be true of a flash, though the dog's eyes will be more dilated without a preflash. Works with hyenas too, but not recommended at close range.:o
My question is when you get :steel Eyes" how do you correct the picture in LR or PS?
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