To maximize laminar flow characteristics, the illumination area 80 is positioned near the upstream end of the flow cell 50. Objects entering the flow cell 50 pass through illumination area 80 where they are illuminated by light source 62. Primary camera 82 is focused at a camera plane having a relatively wide depth of field enhanced by use of a telecentric lens, creating a field of view 81 within the illumination area 80 within which fibers and other pulp objects are imaged. Of course, the field of view 81 will differ from that shown in FIG. 2 for different applications. For example, when measuring shives content, the field of view 81 will typically be larger than when measuring fines content. FIG. 4, which illustrates a typical image captured by primary camera 82 when measuring individual fiber characteristics, shows that the camera's field of view 81 is large enough to include several objects within the image, yet small enough to maintain sufficient magnification to enable identification of most objects by simple visual inspection. For example, in the image of FIG. 4 there can be seen, and readily identified, an individual pulp fiber 110, a broken fiber 112, and dirt 114. To enhance parallel light gathering and increase depth of field, primary camera 82 may be equipped with a telecentric lens.