Hmmmm, this seems to have generated some mail.
I did all the math in my head including rough square root approximations
while typing the original posting. Undoubtedly someone will eventually
crunch the numbers with a calculator so I decided I should first and
confess to whatever approximation error there was. It doesn't really
change the result but is more accurate.
Errata after using a calculator . . .
1. Terminal speed for a 1 meter drop is 9.9 MPH (15.9 kph).
2. Elapsed time of drop is 0.45 second.
3. The actual g-force on an object at the point of impact is still as much
as 500 g's for a 1 meter drop to hard concrete and is only approximate
because the deceleration time is miniscule. [We have a group that measures
the g-forces directly inside and outside our packaging during 1 meter drop
tests. The outside measure is a sanity check to ensure it dropped
correctly. I got the figure for hard concrete from them a while back after
discovering assemblers in a car plant were occasionally dropping our parts
on the plant floor.]
4. The complete deceleration on impact occurs in about 1 millisecond.
5. Subjective analysis about damage still stands.
I read the Leica story a long time ago and had forgotten about it. In
spite of air friction limiting terminal speed well prior to impact, it had
to be *really* moving when it hit. I was surprised at the time it had not
split open, perhaps because the old "Barnack" bodies loaded through a
bottom plate and not through a door or removeable back.
Acer is right about the desert floor; even dirt at near maximum compaction
is *much* softer than concrete. The original artificial turf wreaked havoc
on football players in spite of its padding because of the concrete under
it. My cased Zeiss Ikon Contax IIIa also survived 2.5 foot drop to plush
padded carpet over a wood floor. Checked its meter immediately, then the
rangefinder and shutter timing, then the cast frame inside. In spite of
the case, carpet and flooring, the event scared the daylights out of me. A
never-ready case *does* provide some protection and I don't mind having to
fuss with one. I also use neck straps. Unless the camera is bolted to a
tripod, the strap stays around my neck. Exception: Rollei 35 with wrist
strap which stays around my wrist.
For those who want to do testing to verify what happens when a camera is
dropped, any N*k*n, C*n*n or M*n*lt* would be quite suitable for the task.
;-)
-- John
P.S.
I promise to use a calculator next time.
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