Idris Khan Development

On reflection of Idris Khan's work, I created this piece where I overlayed every image that I had used as my Facebook profile picture since I joined the website. What better way to document the passage of time in relation to myself than using my own face as I choose to represent myself to the online community around me.
It took me a few minutes to work out the best way to do this. At first I changed the blending modes in the different layers in Photoshop on all layers to 'overlay' but that rendered the overall image more or less black with a few red spots, and only the bottom few layers were visible. This wasn't the desired effect I was going for. I then tried using 'lighten' and 'darken' blending modes in a pattern. This almost worked but only the top few layers were visible. I then counted the number of layers, and divided 100 by that number, I then changed the opacity of each layer, starting with 10, and gong all the way up to 100 in 2 increments, changing each layer. so the to layer was 10, the next layer down was 12, the layer below that was 14, and so on until I reached 100.