I have been playing about using the threshold tool in GIMP to convert some of my captures into black and white. I took a few captures of some trees at our local park and was quite pleased with the outcome. Here are the colour versions if you're interested:
Whilst out taking the captures I thought they would make some nice BW prints. However, using my normal technique (aka as trial and error with the channel mixer and levels), the images still did not stand out as much as I would have liked them to. So I decided to check out the Threshold tool and liked the conversion which, whilst not being strictly traditional, is a more striking composition.
A beautiful set, especially the first image: it is confusing, challenges one hard to find references within, and has some fine abstract and impressionnistic qualities.