So we were thinking about shooting some video material and still on a roof.  We thought about it and decided to.  Now we needed a roof.  Wait!! The studio has a roof!!!  We climbed up there and checked it out and all agreed that it was as good a spot as any.  So we went back down and were about to start bringing gear up  (we need tripods and cameras and lenses and dollies and bla bla.. a good amount of junk) when we realized using a rope to tow the gear up and down would be a lot easier than carrying it all up a tiny ladder.  So we did just that, used a rope.  Attached a carabiner to each end and one by one brought up all the gear we needed.  We took some footage and started to bring down all the gear when….. :’( the rope’s knot gave and my Lowepro Vertex 200AW bag with all my gear went a’tumblin’ down down down.

The bag fell from about 23′ straight onto the sidewalk below from the top of the roof.  My heart nearly stopped as I debated going after it for a split second.  Inside the bag was:

2 Nikon D3s’

70-200

24-70

14-24

Sigma Macro

Sigma 50m

85 1.4

extension tubes and a whack of other trinkets like blowers, lens cleaners, memory cards, filters batteries etc.. The bag weighed in at a comfortable 40lbs.

Warning: Math below

Let’s do some quick math to put my high school education to good use yeah?

40lbs = 18.2 kg.

F=ma where m=mass (18.2 kg) and a = acceleration (the Earth’s gravitational pull of 9.8m/s/s)

Therefore F=178.36N :)

What does that mean?  well..

V(f)^2=2a(d) where V is the final velocity of our bag, and d is the distance it covered (23′=7m)

so v•v=2•9.8(7m)=137

therefore V(f)=11.7m/s = a whopping 42km/h!!! wow, imagine a 40 pound bag flying at your head at 40km/h!  That’s intense.

So what happened you ask?  Well I’ll tell you what happened, and I know you’re all dying to hear that all my gear got smashed, but the amazing part of it is, only 3 lens hoods were damaged.  THATS IT!

178N is also roughly the same energy that a 10 pound sledge hammer would output at a speed of 120km/h, so image a massive man swinging a sledge hammer at your bag and hoping just 3 lens hoods get damaged..

I’m fairly confident that while the steel lens hood for my 85 1.4 took most of the force, that there was a bit of luck that the bag happened to land with the part of it where I keep a couple of steel lens hoods stacked inside each other was face down.  

it should be stated that the hood on right of the image above is solid!  I tried stepping on it after taking the image to see if I could bend it and nothing.  So while I lost the hood, I’m glad it took so much damage!  The hood in the middle is actaully pretty much ok, except that the threads where it would screw into a lens are damaged and so I wouldn’t be able to screw it onto anything..

So at the end of the day, this mishap has really left me in a great position, losing only 3 lens hoods is a quick and cheap fix over at Vistek.  I should be grateful to Nikon for building such solid gear, Lowepro for their Vertex keeping my gear ever safe, and the universe for letting my bag land mostly on lens hoods!

Thanks for reading,

David Dvir

This entry was posted on Tuesday, December 7th, 2010 at 5:01 pm and is filed under Updates. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.