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Wide Angle Shot Problem


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#1 lanxx

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Posted 05 April 2003 - 10:15 PM

Whenever I try to take a wide angle shot with my 16mm lens, with the external strobe on,
the picture always produces a 'ring' in the picture. :huh:

Unless I do not use the strobe, then will it only not have the 'ring'
Any suggestions and ideas why this is so?:freak:

Attached below is one of the 'ringed' shot

Thanks

#2 lanxx

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Posted 05 April 2003 - 10:18 PM

B)

#3 PauP

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Posted 06 April 2003 - 01:40 AM

Lanxx

Your picture is showing the reflection of your lens inside the port, caused by light entering the port. Try moving your strobe back a bit, behind the lens.

If you have a wide beam on the strobe you may need to angle it away from your subject a little and just use the edge of your flash beam, keeping stray light to a minimum.

Good luck
PauP

#4 craig

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Posted 06 April 2003 - 05:38 AM

The previous poster is right. Just to clarify, light from the strobe is hitting the external glass of the lens directly. Moving the strobe back and/or aiming it away will fix it. Stray light enters the glass at an odd angle and bounces around inside the glass element for a while, causing the flare that you see.
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#5 lanxx

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Posted 06 April 2003 - 09:39 AM

Thanks for the advice. :huh:

So basically, I need to reposition my strobe, away/behind my lens to slove the problem right?

Maybe some of the strobe light is hitting th lens.
Ok, i will give it try soon

#6 lanxx

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Posted 06 April 2003 - 09:41 AM

Just wondering,
is there any website/articles to show in diagrams/pictures, the solution?

#7 davephdv

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Posted 06 April 2003 - 12:08 PM

Going beyond the light reflected mentioned above; you can see a lot of backscatter in the photo you posted. As mentioned above you need to reposition your strobe. Specifically what you want to do is illuminate nothing between your camera and your subject. You need to know the angle of coverage of your strobe. Angle the strobe so that the edge of the strobe beam illuminates your subject without lighting up any part of the water column between the camera's front dome port and your subject.

If you have your strobe in the same plane as the camera; even if out of the picture frame you may get a hot spot at the side of your picture. If you move the strobe behind the plane of the film you can limit or eliminate this effect.

If you have only one strobe you can hand hold it to get these effects. With two you need to get sets of the long strobe arms. Ike, TLC and Ultralight all make such arm systems that work well.

I find it easier to get good lighting of the subject while limiting backscatter by using two strobes.
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