From: utzoo!decvax!decwrl!sun!megatest!p500vax:yin Newsgroups: net.rec.photo Title: Re: how to use a flash? Article-I.D.: p500vax.168 Posted: Fri Jan 14 14:32:05 1983 Received: Tue Jan 18 19:14:46 1983 References: tekid.726 the problem you describe is called (logically enough) 'redeye'. it is caused by light from the flash entering the pupil of the eye and bouncing off the retina, returning to the camera lens. since the pupil is fairly small, this is only a problem when the flash is in almost a direct line with the camera lens. to avoid it your flash needs to be offset from the usual position on the hotshoe or you need a flash with a position adjustment. any way of offsetting the light path from the direct line will work. flash pictures of people taken by bouncing the light off a light- colored ceiling or wall are usually better anyway. this is because a direct flash is very harsh and eliminates any depth/structuring caused by shadows. if you do bounce, be aware that you will lose about 1-2 f-stops (totally nominal, dependent on actual reflectivity of the surface being bounced off). this is a problem if your flash does not have a light sensor that can be placed in the return path of the light. if you aren't able to do this then you have to open your aperture by the estimated number of stops lost to compensate. - yin shih - megatest, sunnyvale