Hi Geoff;
The 2Lt. is Black Watch, the cap badge is the give away, if he were A&SH, the cap badge would be oval in shape and the 'Glen' would be diced. Also, if he were A&SH, his 'collar dogs' would appear as two joined circles.
Also, this photo is from the early war years judging by the position of his 'pip'
Hope this helps.
Cheers
