Measuring distance with cameria

[XXShadowXX]

see first post, that what i was doing, but as i understand it the angle that objects change size at changes meaning you have to use a curve not only that but you need to account for optical defermations in the lens

[elfinn]

Size of the target is an easily obtained value and would be a more accurate measure of distance than the mass. The mass may be misleading if the particle returned has holes or is truncated by glare or bad parameters. But the height and width of the particle would vary directly with distance.