Originally posted by jt_cph_dk: Hi abruzzi, that´s OK, I´ll never be any good at math—it´s just not my area of abstraction, but I´ll take it from you even so, I just dont get it: Don´t we measure areas with this `number´ (1 meter) by this other `number´ (2 meters) equals some area size (2 M2)?
Regards Jakob
exactly, you were using the 'number' (90%) by other 'number' (90%), and PP was using 'some area size'
Think of it this way. According to the internet, the 6x7 frame size is 56mmx67mm. The area is 56*67=3752 square millimeters
If you reduce the frame width and height by 90%: .9*56=50.4mm .9*67=60.3
so a 90% frame is 50.4mm * 60.3mm = 3039.12 square millimeters
Square millimeters is an area measurement. So what is the percentage difference between the two areas: 3752 and 3039.12?
Simple divide the original size into the reduced size 3039.12 / 3752, and the result is .81. So 3039.12sqmm is 81% the area of 3752sqmm.
So as I said, the two numbers aren't exactly equivalent, but they are very close. Maybe the 77% area is a little too small, maybe 90% distance is a little too large, or maybe both are a little inaccurate and the combined error accounts for the different.