Tissot Chronograph, Valjoux 7750, ca. 1991

What a difference the angle of the light makes!
The previous back shot shows absolutely no hairlines. For this shot, all I did was to remove the reflector card behind the watch and suddenly the (although they are very fine) hairlines appear. So if you buy watches online, be aware of the possibility that the picture does not show all defects. Especially if you buy second hand watches!