I took five pictures in total for the black image, and concentrated on the colour rather than the overall composition - clearly! The median values on the histogram range between 48 and 2, but for the darkest I had to resort to Photoshop to get it that low - the camera didn't take it further than down to 14, perhaps due to the lighter lettering in the image. The darkest black is so much more satisfying than the lighter, which looks very washed out in comparison.
This was a really exciting project - although at first glance it might not seem so! Seeing the variation between these greys and whites was incredible. My subject was some sort of white plastic that formed part of a supermarket's branding, and should therefore have been pretty even. The levels vary between 130 for the darkest grey (bottom) and I again edited the lightest white to get it to 255 as the camera didn't make it above 206. There's a distinct pink tinge on the right hand side of two of the images (the direction the sun was coming from).