A fair indeterminate mixture of both
I use vertical grip
I find underhand my arm will just start to vibrate nonstop like crazy. lols, so overhand for me.
Actually quite a few cams have a "built in" vertical grip ya..
On my recent trip to spain, very cold, so I would plop my dslr onto at tree, hug the tree, and use underhand..
I prefer the underhand method as it gives me more stability. This is the same position as in the shoot position with a rifle, you can tuck in your arm to the body and thus reduce hand shake
Canon 30D, G11, 50 f1.8II, 10-22 f3.5-4.5, 24-70 f2.8L, 70-200 f2.8L IS, EX580II
If we are talking about SLRs here, then I think it should be overhand. The left hand can support the lens and camera, while the right hand holds the grip and ready to press shutter button. If underhand, that means all the right hand got to support, hold grip and press button. I think the underhand is just too awkard a position to use.
For PnS, since we usually do not need much support, both postures would be fine.
just looked through my last couple of verticals and realized that i tend towards using the underhand grip more often, especially with shorter primes. as to stability - tuck both elbows in against the chest, and anchor the camera body against the forehead when shooting.
overhand grip with (physically) longer lenses like the 70-200s.
Overhand for me, seems more natural. I do own a grip but i realised that sometimes I would just conveniently "forget" to use it and end up shooting using the overhand technique LOL
From the view of mechanics.. It seems that overhand, which holds the arm upward dragging a tension on the wrist will seem more stable which involve only one direction of strength apply.
On the other hand for underhand, which the camera is exerting a bending moment at the wrist, requires force to control sideways.
Just my 2 cents opinion. Doctors/mechanics pls correct me
i think women doesnt want people to see their armpits....
Canon EOS 40D | EF-S 17-85mm f/4-5.6 IS USM | EF 50mm f/1.8 II
i use underhand method only when shooting at low shutter speed., i.e. evening time without tripod.