Photographed at Mae Surin Waterfall in Mae Hong Son province, nw Thailand, dry forest at 1,250 metres.
I am pretty sure these are Acytolepis lilacea, based on the various characters mentioned previously here, which should remove Acytolepis puspa as a candidate (eg. small spots, less obvious"tadpole" at base of hindwing etc.).
However, the upperside does not match a number of images on the web exactly, though there appears to be much variation.
Could this be confirmed as Acytolepis lilacea please?
The four images were all taken in the same spot over about a 10 minute period, and as there were a number of these butterflies all looking the same I cannot be sure how many indiviuals are shown here - probably two. I didn't see any obvious A. puspa in this area.