Fig. 7

Impact of uniformity and FOV. a-b FL obscured due to the imaging distance and optical power. a was captured from 10 cm and b from 7.1 cm. The small region of PpIX at the tip of the white arrow was barely visible from 10 cm but more obvious from 7.1 cm. c Illumination uniformity from 10 cm. Within the cropped FOV (inner red rectangle), the uniformity is as shown in Fig. 5b. Outside of this region, and within the maximum potential FOV (outer blue rectangle), the uniformity suffers around the top and sides of the FOV due to the placement of the LED