dg — Much as I appreciate and applaud your use of a coin as a scale indicator in your photograph, I respectfully suggest that on an international forum it's not much help unless you tell us its diameter! Also you don't reveal your country, which makes it even more difficult.
The most useful coin I know for this purpose is the old British ½d (halfpenny), which is exactly 1" (one inch) across, but you have to say as this is only generally known to Brits over the age of about 60. What I would like to obtain and use is one of those photographic scale rulers that you see used in old archaeological reports which show both centimetres and inches as alternate black and white squares — but I've never seen one for sale.
Bernard C.
