Over the years many digiscopers have asked whether stopping down the Aperture will improve depth of field. The consensus appears to be "No!" What I've found w/ the Nikon V1 that stopping down (going to higher f-stops) seriously affects exposure - in a negative way. The two images shown below were taken moments apart using the Nikon V1 and 10-30mm lens (operating in Aperture-Priority, Auto-ISO 100-400) on a Zeiss 85T*Fl and 40X W eyepiece .
When you factor in ISO, there is a full 2-stop difference in exposure between the two. Result? When digiscoping w/ the Nikon V1 in Aperture-Priority make sure the Aperture is as Wide Open As Possible! You'll get faster shutter speeds, lower ISO, and more-corrected exposure.