Cloth sleeve patch

[Blackblue]

This photograph is of a great uncle of mine and his sister. He was a Robertson from Glamis and I beleive the photo was taken early in the war. A number of brothers served with the Black Watch during the Great War as it appears this gentleman did.

I posted this photograph on the old forum but am now after some more advice. I am trying to identify the battalion and hope to do this via the formation insignia which appears on his right sleeve. The photo is very unclear and I have done my best to enhance it. It appears to be a cloth patch of a thistle similar to the 9th Division white metal patch used later in the war. Any ideas much appreciated.