I asked for advice on how many lumens per metre would be sufficient to provide task lighting above a desk and I was told it came down to 'personal preference'. I took a risk and chose 410l/m which I have now discovered is absolutely hopeless. It provides a faint glow. Definitely not sufficient to provide task lighting above a desk under any circumstances. I wish the sales staff had experience in selecting appropriate lighting as I have now wasted my money and will need to replace these lights with something at least twice as bright.