found this easy equation , I'm sure a lot of you know it but it's dead easy for anybody that does'nt
the formula is
F2 / (fstop x circle of confusion) answer is in mm

F2 = focal length of lens
fstop = self explanatory
circle of confusion = 0.020 for all sony alpha dslrs except full frame which is 0.030

so my lens set at 50mm f16 on my sony alpha 700 would be

50x50 / (16x 0.02 )
=
2500/ 0.32
=7812mm = so i focus on 7.8 mtrs using the gauge or window on the lens, and the hyperfocal distance would be half that ie 3.9mtrs to infinity

just remember the simple equation or jot it down for use in the field,sorry if you've all heard this before