Thankyou very much everyone,
So going from these estimations, we could be looking at a birth date 0f around 1870-1880?
this could be great. Because I have a Kate Pearson b.1880 in my tree, She married a Thomas Bristow. And amongst the photo's where we found this picture was a photo that had written, "Old Grandad Bristow" on the back. so we knew that was him. If this photo was in the same collection of belongings, there is a good chance it might be Kate Pearson we are looking at.
The other potential person I thought it could be was born in 1853, so a bit older and less likely.
Carol, I have asked my mum to snap a pic of the back of the photograph and send it to me, so as soon as she has done so, I will add it to see if that gives any more info.
thanks everyone,
Shaun