Reply to thread

Message

<blockquote data-quote="Revet" data-source="post: 250348" data-attributes="member: 17612">Ok,&nbsp; I repeated the experiment outside in the dark, shooting at my off-white garage door.&nbsp; This time the results were much closer to the expected result.&nbsp; When I was twice the distance, I had to increase flash power by two stops to get a similar exposure.&nbsp; It was slightly more exposed but I attribute that to the snow on the driveway acting as a bounce.&nbsp;I think this demonstrates nicely that a close by white ceiling and wall will definitely affect your exposure even if using direct flash.&nbsp; I think it also shows that bouncing a flash puts more even light into a room; ie. in the first trial indoors I only needed to increase the power by one stop when I doubled the distance because of the close proximity of the flash to the ceiling and the wall.&nbsp; I assume the bounced light off of these reflective surfaces influenced the exposure enough that I only needed one stop increase in flash power to get an equal exposure at half the distance.&nbsp; And yes, the distance of the camera to the subject was not a factor so the inverse square law holds if the flash is on the camera, moving with it, or off the camera, moving independent of a fixed camera position to the subject. Thanks for all the comments!!</blockquote>

[QUOTE="Revet, post: 250348, member: 17612"] Ok, I repeated the experiment outside in the dark, shooting at my off-white garage door. This time the results were much closer to the expected result. When I was twice the distance, I had to increase flash power by two stops to get a similar exposure. It was slightly more exposed but I attribute that to the snow on the driveway acting as a bounce. I think this demonstrates nicely that a close by white ceiling and wall will definitely affect your exposure even if using direct flash. I think it also shows that bouncing a flash puts more even light into a room; ie. in the first trial indoors I only needed to increase the power by one stop when I doubled the distance because of the close proximity of the flash to the ceiling and the wall. I assume the bounced light off of these reflective surfaces influenced the exposure enough that I only needed one stop increase in flash power to get an equal exposure at half the distance. And yes, the distance of the camera to the subject was not a factor so the inverse square law holds if the flash is on the camera, moving with it, or off the camera, moving independent of a fixed camera position to the subject. Thanks for all the comments!! [/QUOTE]

Verification