I've never photographed dunes before, so take what I say with a grain of....sand.
Thin negatives implies underexposure. What zone are you placing your shadows on? If you're placing them on zone III, you may be losing some local contrast, since part of what makes up the 1 degree area on your spot meter may be zone II 1/2, and part may be III 1/2 which averase out to zone III. If you place the shadows a bit higher on the scale, you'll increase the amount of local contrast in the shadows. Yes, your negatives will be a bit more dense, but that's ok since todays film can handle the extra exposure without blocking up the highlights.
I won't recommend bracketing, since 8x10 is relatively expensive, but perhaps a test the next time you're out may be in order.
The other thing to keep in mind is that depending on the time of day, dunes can have very little contrast, requiring (sometimes greatly) increased development to get any decent contrast. If you are doing any sort of N+ development, I would avoid decreasing exposure to compensate, since you will lose contrast in the shadows.
Using a orange, or even an red filter will help with contrast, but I think extended development will help more.
Last edited by KenM; 06-29-2004 at 04:54 PM. Click to view previous post history.