Red Eye at DVinfo.net

Dana Salsbury · August 26th, 2009, 11:10 PM

I've never had this problem before, but on the photo/video shoot our cam picked up a bunch of red-eye. In post I made it B/W, but I'm surprised to see it on video. I think we were going without a diffuser on this one as it was really dark.

Philip Howells · August 27th, 2009, 02:18 AM

Any camera-mounted light can create red-eye, it's not confined to stills. If you must use one on a wedding (I would personally be concerned about destroying the ambiance and in any case we prefer to work unnoticed) either move it off-axis or bounce it.

On the wider topic of lighting, we always ask our clients in the briefing if we can arrange to bring up the room lights for the speeches. Once they understand why (so we can record good pictures) they never disagree. We pass this "client request" on to the hotel.

Hotels like it also because it means they can encourage the guests to vacate the room so they can reset for the evening entertainment.

Chris Harding · August 27th, 2009, 07:09 AM

Hi All

Well I have learnt something new today!! I thought that red eye was only created by flash units not direct lighting!! I must admit I have never seen the problem arise with my LED light panel on the cam!! (But then again that's mainly used for the odd footage of dancing when the lighting is really low) Maybe the fact that I use warm white LEDs and they have quite a soft diffused output helps???

Even with Halogens and their fierce light I haven't ever seen red eye on video!! What light unit are you using on your HMC170 Dana??? ( BTW: I'm just being quizzy now...what model is an HMC170??? ... Is it Panasonic P2???)

Chris

Philip Howells · August 27th, 2009, 07:32 AM

Chris, the reason is that the red eye effect reduces as the pupil closes. In low light (or under the effect of certain drugs I'm told (!) the pupils dilate (open up). Since the duration of a flash is short the pupils typically don't have time to react and close and the inside of the retina (blood cell endings) is illuminated. If the camera lens is on or near the same axis we actually photograph the inside of the eye.

The phenomenon isn't usually seen in video because the light is continuous and the pupils close, limiting or preventing the effect.

My guess is that Dana's light, especially if it's an LED, is a pretty narrow beam. There may not therefore be enough general light to trigger a closing of the pupils. If the light is mounted on the camera the axes may be close enough to create red-eye.

We use three 3W LED torches on mic stands to illuminate the darkest wedding dances and before we raised the stands high and angled the torches down we have captured the same effect. Fortunately we also have a friend who's an eye surgeon and so all this apparent erudition is actually experience bought not taught!

On the other hand, maybe Dana was recording a very private party and the subjects' pupils had been stimulated to remain open by some other agent (!)

Dana Salsbury · August 27th, 2009, 06:37 PM

It was a wedding and the photographer took the couple out into the woods after dark. We usually use LEDs, but used a Halogen because it was brighter. It was shot with an FX1. (The couple couldn't pay the remainder for several months, so I'm just now editing.)

August 26th, 2009, 11:10 PM	#1
Dana Salsbury Major Player Join Date: Oct 2006 Location: Phoenix, AZ Posts: 859	Red Eye I've never had this problem before, but on the photo/video shoot our cam picked up a bunch of red-eye. In post I made it B/W, but I'm surprised to see it on video. I think we were going without a diffuser on this one as it was really dark. __________________ www.LegacyHDV.com Weddings \| Corporate \| HMC150s \| FCPX \| Encore \| Lion

August 27th, 2009, 07:32 AM	#4
Philip Howells Trustee Join Date: Jan 2009 Location: Manchester UK Posts: 1,212	Chris, the reason is that the red eye effect reduces as the pupil closes. In low light (or under the effect of certain drugs I'm told (!) the pupils dilate (open up). Since the duration of a flash is short the pupils typically don't have time to react and close and the inside of the retina (blood cell endings) is illuminated. If the camera lens is on or near the same axis we actually photograph the inside of the eye. The phenomenon isn't usually seen in video because the light is continuous and the pupils close, limiting or preventing the effect. My guess is that Dana's light, especially if it's an LED, is a pretty narrow beam. There may not therefore be enough general light to trigger a closing of the pupils. If the light is mounted on the camera the axes may be close enough to create red-eye. We use three 3W LED torches on mic stands to illuminate the darkest wedding dances and before we raised the stands high and angled the torches down we have captured the same effect. Fortunately we also have a friend who's an eye surgeon and so all this apparent erudition is actually experience bought not taught! On the other hand, maybe Dana was recording a very private party and the subjects' pupils had been stimulated to remain open by some other agent (!) Last edited by Philip Howells; August 27th, 2009 at 07:34 AM. Reason: clarity

August 27th, 2009, 06:37 PM	#5
Dana Salsbury Major Player Join Date: Oct 2006 Location: Phoenix, AZ Posts: 859	It was a wedding and the photographer took the couple out into the woods after dark. We usually use LEDs, but used a Halogen because it was brighter. It was shot with an FX1. (The couple couldn't pay the remainder for several months, so I'm just now editing.) __________________ www.LegacyHDV.com Weddings \| Corporate \| HMC150s \| FCPX \| Encore \| Lion

August 27th, 2009, 02:18 AM	#2
Philip Howells Trustee Join Date: Jan 2009 Location: Manchester UK Posts: 1,212	Any camera-mounted light can create red-eye, it's not confined to stills. If you must use one on a wedding (I would personally be concerned about destroying the ambiance and in any case we prefer to work unnoticed) either move it off-axis or bounce it. On the wider topic of lighting, we always ask our clients in the briefing if we can arrange to bring up the room lights for the speeches. Once they understand why (so we can record good pictures) they never disagree. We pass this "client request" on to the hotel. Hotels like it also because it means they can encourage the guests to vacate the room so they can reset for the evening entertainment.

August 27th, 2009, 07:09 AM	#3
Chris Harding Inner Circle Join Date: Jul 2009 Location: Perth, Western Australia Posts: 8,441	Hi All Well I have learnt something new today!! I thought that red eye was only created by flash units not direct lighting!! I must admit I have never seen the problem arise with my LED light panel on the cam!! (But then again that's mainly used for the odd footage of dancing when the lighting is really low) Maybe the fact that I use warm white LEDs and they have quite a soft diffused output helps??? Even with Halogens and their fierce light I haven't ever seen red eye on video!! What light unit are you using on your HMC170 Dana??? ( BTW: I'm just being quizzy now...what model is an HMC170??? ... Is it Panasonic P2???) Chris