Red eye

[nilantha]

I was shooting an award ceremony (Elan II, Sigma 70-200 2.8 HSM, 540

EZ mounted on camera, 400 ASA) under relatively low light

conditions. Most of the participants, even the ones not directly

looking at the lens/camera got red eye. I have done nighttime

photography but not have seen this much red eye. What went wrong

here is a puzzle to me. Any suggestions are welcome.

[mark u]

Red eye appears when the angle between the lens axis and the flash axis is small. The angle is reduced by using longer focal lengths and consequent greater subject distances. To avoid it, you can either use bounce flash or increase the angular separation of flash and lens by using an off shoe cord.

[the_macman]

ASA?

[jbq]

Long lens. You need to move the flash further away from the lens.

[harman_bajwa]

<i>"ASA?"</i>

<p>

 

HTH:

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<a href="http://www.photographic.com/film/159/index5.html">http://www.photographic.com/film/159/index5.html</a>

<p>

 

- Harman

[simonpg]

For the reasons the others above have said I always use a Sto-fen soft box on my 550ex and 420ex when directly shooting at people indoors and outdoors when it is impractical to bounce flash or take the unit off-camera.

 

It also produces a nicer light that still covers big groups using a 550ex. I have never ever has one shot with red-eye using any lens and I shoot lots with the 70-200mm f2.8L with the flash on camera.

[the_macman]

ISO... 7Welcome to 2004. ASA has been dead an burried for decades.

[yakim_peled1]

Everything everybody says is correct but I still think it's weird. I never got red-eye with my 420EX or 550EX, no matter which lens I used (24-35-85-200). I can't see how the 540EZ be any different as it's basically a 550EX without E-TTL.

 

Happy shooting ,

Yakim.

[awindsor]

Macman. Everyone misuses ISO. 400 is an ASA specification and not an ISO one. The equivalent ISO is 400/27?, which combines the ASA and DIN.

 

Thus 400 ASA is correct and 400 ISO is not.

 

The focal length of the lens has only incidental effect on redeye via the crucial distance to the subject. If you have a long distance to the subject then the angle between the flash and the lens axis is small enough that the portion of the retina illuminated by the flash is visible to the lens. At long subject distances there is little you can do short of using assistants and slaves to move the flash far enough away. If you can bounce the flash light then this works well for eliminating red eye though you might have insufficient flash power.

 

The best solution for subject far away is to post-process the image digitally to remove the red eye. Many labs will do this for you when printing your picture.

[J.W. Wall]

Or correct it in PhotoShop.

[michael_peters1]

<i>ISO... 7Welcome to 2004. ASA has been dead an burried for decades.</i>

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I still prefer DIN - it made more sense to me.