I was charging about like a nutter photographing Clouded Yellow butterflies - a beautiful summer visitor. Lots of blurry yellow blobs and a couple of decent shots - including the light coloured one above. Did I happen to photograph a very rare Pale Clouded Yellow?
I was on well known butterfly hotspot; Hutchinson's Bank in Croydon - and it's got form for them - one was confirmed there in 1976! It's probably not, but I've sent the photos over to those in the know and I'm waiting to hear back! Normal one below for comparison.