Wednesday, November 4, 2009
Convention Center, Exhibit Hall BC, Second Floor
One difficulty in the routine analysis of fine root diameter response to environmental stimuli is the lack of scanners with resolutions above 189 p mm-1 (4800 dpi). A 10% change in diameter of a 0.1 mm diameter root is 0.01 mm or 2 pixels at 189 p mm-1. Because of innate variability, images need to have a resolution that has a 4 pixel shift when a 10% change occurs (i.e. 378 p mm-1 or better). Some pasture grasses have fine roots in the 30 micron diameter range, requiring resolutions of 1324 p mm-1 or a relative pixel size of 0.8 micron. We have achieved a resolution of 1600 p mm-1 by coupling a computer controlled stepper motor X-Y-Z system to a Zeiss dissecting microscope and a 14 Mp digital camera. The system can be programmed to do image slicing, thus providing high resolution images of three-dimensional objects without depth of field artifacts.