Archived from groups: alt.comp.periphs.dcameras (
More info?)
CSM1 commented courteously ...
> Flash exposure depends on the distance from the flash to
> the subject, the aperture and ISO. Shutter speed is not a
> big factor, except in the case of a focal plane shutter,
> which a lot of 35mm cameras had. Keep the shutter speed
> above 1/60 to minimize camera shake.
>
> Flash distance says max distance for Nikon 5700 built-in
> flash is 9-13 feet depending on wide or tele.
>
http://www.dpreview.com/reviews/nikoncp5700/page2.asp
>
>
> Vivitar 728 Zoom for Nikon AF.
> http://www.adorama.com/VV728NKAF.html?searchinfo=vivitar%
207
> 28&item_no=3
>
> The Vivitar 728 has a Guide number of 92 at ISO 100.
> The Nikon 5700 has a max aperture of f2.8, so the max
> distance is
>
> GN/F= Distance in feet. or GN/D=F where D=Distance in
feet.
> GN= Guide Number
> F=aperture (f number)
> 92/2.8=32 ft
>
> If the Nikon 5700 is set on aperture priority, ISO 100 and
> the aperture is set at 2.8, then you should get good
> exposure at up to 32 feet with Wide.
>
> Tele is F4.2, so
> 92/4.2=21 ft.
> The max distance Tele is 21 feet at f4.2 ISO 100. Nikon
> 5700 set to aperture priority, ISO 100.
>
Thanks, for the Vivitar link, CSM. I'm aware of the things
you put in your reply. I posted a much more detailed
description of my problem(s) this morning and what I've done
so far to fix it.
Distance is *not* the problem with either the Speedlight or
my Vivitar. A higher ISO won't help at all, since I'm
shooting well within the ranges of these flashes at 100,
plus my experience with my 5700 is that anything about ISO
200 makes my pictures look like they were painted on beach
sand, the noise is so bad.
I believe that something in the 5700 is incorrectly
interpreting the reflected light from either flash, which I
think is the only determining factor in exposure with a
5700.
BTW, I'm using Programmed Auto but, to my knowledge, that
isn't a factor either, as the 5700 locks the shutter at
1/125 and the aperture to wide open when it is in flash
mode.
--
Jerry