I had a couple hours strong sunlight remaining at the end of the day, though it was breezy and conditions were far from ideal. I saw about 20 butterflies, all in a patch just out of the wind. (The image below is a Brown Argus feeding on Ragged Robin.)
The image below was one of the in-focus shots enabling some heavy cropping without losing too much detail. The low ISO of 200 also helps cropping without the image becoming too grainy.