I have an issue with knowing when to black and white a photo versus keeping the colour in it.
How do you decide when to b/w or keep the colour?
In photography, there are the following elements to bring out the message in the photo :
colours, shapes, lines, form, volume, patterns, textures, depth, perspective, scale (relative sizes), symmetry, balance, tones and lighting.
For colours, different colours elicit different emotional responses from the viewer and are all seeking different levels of attention; for e.g. red may suggest "danger" and is screaming for attention while light blue conveys "calm", "cool" or "tranquility" etc.
So there are many things in the photo seeking the attention of the viewer and how much attention they each get depends on the composition.
If colours are taken out of a photo, then the other elements are given more power to catch the viewer's attention and become much more apparent. So black and white photos are good to bring out much more vividly the lines, shapes, form, volume, symmetry, tones and lighting etc. since colours are distracting and may elicit unwanted emotion response from the viewer.
So I b/w whenever the message in my photo is about the elements other than colours.....especially about lines, shapes, form, volume, symmetry, tones and lighting.
I ask myself what was the main thing I wanted to shoot when I took the photo. If it's about lines, shapes, volume, symmetry, tones and lighting, then I would go b/w as this will give the photo the message I wanted and be more likely to elicit the wanted emotional response from the viewer (including myself). So the b/w picture will turn out "nicer" because it is the effect I want.