Close up of the word "FIFTY" on a 50cents coin.
Reverse mount 58mm lens onto Sony DSC 707 at full optical 48.5mm zoom or 190mm in 135 film format.
Calculation of the magnification factor for a 135 format film camera,
focal length of lens mounted to camera / focal length of the lens thats reverse mounted.
So in this case, should it be 190 / 58 or 48.5 / 58?
I am thinking it cant be 190 / 58 = 3.2x mag factor.
It looks more like 48.5 / 58 = 0.8x mag factor (which in this case reduction factor).