Trying to work on a 16bit grayscale image created from a DEM, shows up black no matter what I do

Question

The image is basically a grayscale height map created from Digital Elevation Models, and exported out of another program as a 16bit tiff. I know photoshop can handle the idea of a 16bit image, but no matter what I do, these come out black. i've tried dumping it out as signed, unsigned, stretched, etc. I can't mess with things like contrast or brightness globally cause that will alter the values which have to stay the same.
Basically it needs to open in photoshop cs5 as what it is and save off the same way.
I don't have any other way to do what I need to do to it other than photoshop, so if there is a way to make this work, and someone knows it, I'd sure like to hear it.
and no, converting it to 8bit is not an option.
thanks to anyone who can shed any light.

Answer 1

timbranan wrote:
hmm.. that is.. not helpful. Curious why they would choose to do it this way.
I believe it was chosen to simplify and speed up calculations.
that may make all this a moot point if its gonig to wreck my values regardless.
I was wrong to say that all output values will be even, but you do have an equivalent loss of precision. Here are examples of input and output:
in
out
0
0
1
2
2
2
3
4
4
4
5
6
32766
32766
32767
32768
32768
32768
32769
32769
32770
32769
32771
32771