I decided to post another question to #AncestryHour on Twitter this week, on the vague off-chance someone might be able to identify anything from the mysterious two photos in the old family album, which may or may not be of my serving great uncles.

For the photo of the seated soldier - the one used in the poster for the website and talk - the key seemed to be in being able to decipher the cap and shoulder badges. But this seemed like a hopeless task, given the lack of any visible detail in such tiny areas of the photograph.
Furthermore, the shape of the cap badge looked nothing like the Durham Light Infantry crown and bugle. Tantalisingly however, it turned out that the shape could match that of the Northumberland Fusiliers, but there were other regiments' badges with similar shapes, so it was hard to say anything much more than that.
Then I decided to go back to the original print. It took me a while but I eventually located my daughter’s ‘pen microscope’, and when I focused it in on the print I was amazed at the detail which was visible from actually going back to the original photo. I then fashioned a method of taking photographs with the camera on my phone through the microscope.

This rather odd set up proved surprisingly effective. I could make out that the cap badge was a person on a horse holding some kind of stick – perfectly matching the badge of the Northumberland Fusiliers! This was exciting!
Then to the shoulder badge. The photos I had taken of this made no sense - until I thought I might try inverting the photo. And there it was: the letters ‘N' and 'F’ were clearly visible. Again, the Northumberland Fusiliers and not the Durham Light Infantry.

So this all matched up with the expectations that the mystery photo might be of my great uncle Fred Cowling, who served with the Northumberland Fusiliers and then the Durham Light Infantry. The clues were there all along in the original photo! So yet again a feeling that the information is all out there waiting to be discovered - it just requires some detective work.
The only nagging doubt which remains is the chevrons on the sleeve – by far the easiest thing to make out - which imply a rank of sergeant, and that still seems wrong for my great uncle as he was only promoted to second lieutenant, and that can’t easily be explained away.