# Preventing Red Eye with on camera flash.



## Garbz (Jan 4, 2006)

Is there any easy way to prevent red-eye photos? The red-eye reduction in modern cameras what does that do? I assume it makes people glare into the flash as apposed to the lense. By this logic eliminating redeyes should be as easy as getting people to focus somewhere beside the camera?


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## dsp921 (Jan 4, 2006)

Garbz said:
			
		

> Is there any easy way to prevent red-eye photos? The red-eye reduction in modern cameras what does that do? I assume it makes people glare into the flash as apposed to the lense. By this logic eliminating redeyes should be as easy as getting people to focus somewhere beside the camera?


Red-eye reduction triggers the flash a few times before the picture is taken, that is supposed to close the pupils and eliminate the reflection of the flash from the back of the eye. Works OK most of the time.  It's more of a problem with on-board flashes since the flash is close to the lens it bounces back more directly to the lens.  Only problem is that some people think the picture has been taken when the flash strobes and they move...


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## Revel (Jan 4, 2006)

The red eye reduction in modern cameras. I believe that the flash fires of several flashes which causes the pupils in the eye to dilate ( narrow ) thus reducing the risk of light bouncing off the back of the eye. This is my understanding, but im sure somebody will know for sure.


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## Revel (Jan 4, 2006)

bugger, somebody can type quicker than me :lmao:


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## Garbz (Jan 4, 2006)

dilate means to widen  but I know what you mean. Ithought it may have had something to do with where people were looking. Oh well.


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## Revel (Jan 5, 2006)

Garbz said:
			
		

> dilate means to widen  but I know what you mean. Ithought it may have had something to do with where people were looking. Oh well.


 
I realised after I posted it was wrong. I left the ambulance service in 2001 and things start to get a little rusty. Thank god I still know what a myocardioinfarction is :lmao:


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## Garbz (Jan 6, 2006)

I think you mean "myocardial infarction"  lol. Heart attacks


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## ajmall (Jan 6, 2006)

the problem i find is that it doesn't get rid of red eye, it only reduces it. I'm not happy with ANY photos that have either a small amount of red eye or a large amount....


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## Rob (Jan 6, 2006)

Redeye is caused by the flash illuminating the blood cells at the back of the eye (retina wall) and can be avoided by three main methods:

Rapid successional flash - usually called red-eye reduction - this closes the pupil making the red circle smaller.

Diffuse soft flash - using a Rizla or crepe paper to create a small soft box light instead of a hard flash.

Moving the flash away from the lens - this is the best method as it prevents a direct reflection from the back of the eye to the lens. The best two ways to achieve this are with a tilt-head flash and bounce off a reflector or the ceiling, or my preferred method of using a PC lead to take the flash off camera completely.

Hope this helps!

Rob


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## ajmall (Jan 6, 2006)

Rob said:
			
		

> Redeye is caused by the flash illuminating the blood cells at the back of the eye (retina wall) and can be avoided by three main methods:
> 
> Rapid successional flash - usually called red-eye reduction - this closes the pupil making the red circle smaller.
> 
> Diffuse soft flash - using a Rizla or crepe paper to create a small soft box light instead of a hard flash.



ahh rizla paper! i've never thought of that one! genius


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## DLL_4ever (Jan 6, 2006)

How come i never get a red eye when i take close-up photos of my eyeball? Even when the redeye reduction is turned off, it still turns out perfectly normal:


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## Revel (Jan 6, 2006)

Garbz said:
			
		

> I think you mean "myocardial infarction"  lol. Heart attacks


 
lol. now you know why im not a medic any more.:lmao:


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## RickyN29 (Jan 8, 2006)

DLL_4ever said:
			
		

> How come i never get a red eye when i take close-up photos of my eyeball? Even when the redeye reduction is turned off, it still turns out perfectly normal:


 
Wow, what a pretty eyeball you have!  My guess would be your eye is so close to the lens that the reflection from the retina is not hitting the film/sensor.


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## DLL_4ever (Jan 8, 2006)

/\ I see.. thank you! :cheers:


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## markc (Jan 8, 2006)

ajmall said:
			
		

> ahh rizla paper! i've never thought of that one! genius


Another good one is a piece of a plastic milk jug.


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## PachelbelsCanon350D (Jan 8, 2006)

RickyN29 said:
			
		

> Wow, what a pretty eyeball you have!  My guess would be your eye is so close to the lens that the reflection from the retina is not hitting the film/sensor.



I'm pretty sure that's exactly what it is. The camera is SO close to your eyeball that the angle at which the flash is hitting your eye is such that the light comes from 2 inches above your eye. If you shot a photo of your eyeball from 5-10 feet back, with no red-eye reduction, I bet it would look devilishly red


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## DLL_4ever (Jan 8, 2006)

PachelbelsCanon350D said:
			
		

> I'm pretty sure that's exactly what it is. The camera is SO close to your eyeball that the angle at which the flash is hitting your eye is such that the light comes from 2 inches above your eye. If you shot a photo of your eyeball from 5-10 feet back, with no red-eye reduction, I bet it would look devilishly red


I should try that! Unfortunately i cant right now since my current camera is in for repairs, and my new one hasnt been ordered yet... :-(


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