Picasa, which you can still download for free, has a wonderful little posterizing filter that is ideal for investigating the Notan of an image. This filter is in the second last filter tab on the main tools panel displayed when a single photo is selected. It is design to reduce the number of colours actually being used (the top slider) and this is original of the name posterization because the image begins to look like older style posters which where printed with only a few colours. In the case of investigating notan we are looking for just a black and white image, and all you need to do is move all the sliders to the left (BTW In picasa you never get a pure white using this tool but it is very close), Our eyes are always drawn first to edge of sharper contrast, so it is easy to see that the movement all flows along there strong boundaries of dark and light shapes to the wheel of more particularly the hub cap ( and this puts the main point of interest right on the edge of the frame. Poor design and bad composition. This is so called two value notan, and some artist recommend including a third tone (the mid grey) three value notan. In picasa you can tweak the top slider a fraction to the right an get the three value version (see centre image below). There is also a very useful detail slider which will progressively display more detail (smaller bumps and shapes).
To see how this might be applied to photgraphy I will use couple of photographs I took for this week’s PhotoFriday’s topic clean. My original idea was to have the foam and green bucket being the focus to covey the story clean(ing). Ok the photo is really bland, so lets look at the notan.
Once I saw the black and white shapes I realised that the cleaned section of the car and the soap suds where lost in the composition. Worse still is the light and shapes just break the space in two and the movement and point of focus are on the wheel at the edge of the photo. Even when I consider the mid tone I am not gaining any interest around the cleaning story. Luckily I took more photos including some of me actually cleaning.
The balance of light and dark is no longer so symmetric, and thus more interesting also, the dark shape of my arms help draw the flow of interest into the area being cleaned. With this insight I could them focus on this balance when doing my final post processing.
This video nicely covers the concept of using notan in building the underlying strength and composition of a painting, but it does also use notan examples created from photos