This is like the condensation threads.... generally correct in spirit but still a fair bit of physics misconceptions going on here, some quite dangerous
Without boring everyone to tears again (hopefully?), the short version is the only real safety is in not being exposed in an electrical storm. That is
the defining risk element, the rest is largely inconsequential.
Long version:
Lighting forming tens of thousands of feet in the air doesn't care about small formations like tents, people, camera tripods, or even houses and buildings. It goes for the general area with the largest broad-scale opposing charge buildup, and the smallest average air gap. Typically, this is the highest body of earth immediately under the area of electrical activity ie hills and sometimes really big buildings.
The voltages involved are are mind-boggling. They make high-voltage transmission lines look like AA batteries. We can't even accurately measure them. At those voltages, EVERYTHING is conductive. Remember, lightning is sometimes arcing over
kilometers of air already - a few cms of rubber in our shoes soles or camp mat is pretty much entirely irrelevant.
Lightning will descend down in 'stepped leaders' - a 'feeler' strike that randomly branches as it heads towards the ground. It's not until one of those branches gets quite close to individual features that they MIGHT influence the strike location. Rule of thumb is the 'circle of influence'; if one of these leaders happens to come within a circle of a radius equal to the height of the object, it may induce a static charge on said object thats strong enough to produce an upwards streamer that meets the downward leader, and complete a discharge path aka a strike.
It's not a hard and fast rule and is influenced by various factors, but the take-home point here is for your average person-sized meatsickle, exposed in an electrical storm, you will only 'attract' the lighting if it was already going to 'land' withing a meter or two in the first place - ie dangerously close. At this distance, with the forces involved, things like metal pack frames and wet tent skins are vanishingly insignificant. You could be wearing a tin pot on your head - as far as the physics go, it doesn't make a lick of difference in terms of strike probability (it may, however, impact the nature of injuries cause by said strike). Similarly, if you were 50m from a tree and it got struck by lightning, the lightning was likely already going to hit around that spot, even if the tree wasn't there. Different story for a radio tower - not because it's metal, but because it's got a zone of influence in the order of hundreds of meters wide, not to mention a notable reduction in the airgap between cloud and earth. It's only once you get to things that big that there's a diversion of real consequence.
The byproduct of this, though, is the unfortunate myth of the 'cone of protection' - namely that by standing within height 'h' of said radio tower, you're allegedly afforded some protection due to it 'drawing in' any strikes. The reality is that it's no guarantee - remember, the numbers here are insane. The tall objects can accumulate so much opposing charge that it 'overflows' into surrounding objects (ie you), which can then launch their own upwards streamers, or side flashes, should a stepped leader chance close enough. There's plenty of photo evidence of just this phenomenon happening - bolts striking the side of towers, nearby trees, the ground, or combinations of all of these. And even if it does strike the highest object, the subsequent ground distribution will likely harm you if you happen to be that close to the object anyway. There's so much power here it will go anywhere and everywhere it can.
The advice about keeping away from particularly tall stuff and crouching with your feet close together is theoretically reasonable for reducing the effects of ground differential potential near a strike (somewhat...), but even that is pretty specious as practical advice.
The practical truth is there is really nothing you can do. Any advice other than "Don't Be There" has no support in physics and could give people a dangerous sense of safety that doesn't exist. Avoiding metal tent poles, camera tripods, basalt (???), tent pegs, water puddles won't help at all. Neither will rubber mats, or being in a forest. Lying down on your sleeping pad is a terrible idea that actually increases risk of harm. Better to stand straight up.... and run, as fast as you can for lower ground or substantial shelter.
Further reading if interested:
http://stormhighway.com/small_metal_obj ... g_myth.phphttp://stormhighway.com/reduce_risk_lig ... tdoors.phphttp://emergencypreparedness.cce.cornel ... yths-1.pdfhttp://www.wec.ufl.edu/safety/backcount ... safety.pdf (note the stats on types of lightning mechanisms responsible for death)
* If you're reading this and wondering "Ah but why do tall buildings have big METAL lightning rods, if not to attract lighting?". Lightning rods are designed as
accumulation points for the static charge that builds up in large, tall objects. This DOESN'T make the building any more likely to draw lightning from afar than it would be without a rod. Where is does help, is to increase the chances of the rod (vs say some expensive antenna) being the source of the upwards streamer, should a downward streamer be drawn in the building's innate area of influence. Being metal, it then acts as am (often sacrificial) path of least resistance for said strike, saving the rest of the wiring and/or people, in the building and also conducting it deeper into the earth, reducing the risk of dangerous differential ground potential at the structure base. While standing in an open field holding an umbrella would technically act in a similar way, it's a far, far, faaar smaller effect and again, if the leader chances close enough to be affected, you were going to have a bad day anyway.