There are basically 4 ways to talk to cameras, with varying degrees of
support, both in the camera and in NetBSD:

1. proprietary transfer protocol over USB, firewire or even serial.
   The Nikon 990 (was pretty new in December 2000) does this.  I think
   most recent cameras don't.  gphoto and related programs are the
   software to look for; I have used gphoto with the 990 under
   FreeBSD, but don't bother any more (see point 4).  This should work
   under NetBSD, or be easy to make work.

2. PtP, or picture transfer protocol, is an at least semi-standard
   photo transfer over usb and probably firewire.  My impression is
   that most modern cameras do this, and I'm pretty sure the Nikon
   5700 does (a friend has one; I haven't seen this work personally
   under BSD).  gphoto2 probably deals with this.

3. umass: Modern cameras can often be set to look like umass (rather
   than ptp), and then show up as the usual umass/scsibus/sd0.  The
   Nikon 5700 can do this.

4. Take out the media, and put it in a reader.  In my case, I pull the
   CF and either put it in a CF->PCMCIA adapater or in a USB CF reader
   (SanDISK SDDR-91 works great, $20).  Mount the dos fs, and cp of
   the .jpg/.tif/.nef files.

I now always use method 4, because it doesn't require the camera to be
on and using battery.  But PtP is attractive also because you can
probably adjust settings, take pictures, etc. via computer control.

-- 
        Greg Troxel <gdt@ir.bbn.com>