A grip need not just be a grip. It can also do one or more of:
* pistol-grip (with or without remote trigger)
* serve as a flash bracket for off-camera flash
* lower the camera's center-of-gravity, providing stability
Some systems (e.g., SteadiCam Solo) even offer:
* extend into a monopod
* ability to connect to a body harness
A simple flash bracket is worth considering: cheap, easy to grip, great for
flash and works with any camera. As long as your flash can tilt, the
simple L-shaped ones are sturdiest. But they don't lower the camera's
CG (much) or keep the camera balanced. Around $10.
Just attaching the camera to a collapsed monopod gives you a pistol grip,
lowers the CG and provides some inertial damping.
There are a couple of supports advertised that are shaped like a rifle stock.
But the mounting hardware isn't very good and they lack triggers and
don't lower the camera's CG.
The fact that so many different camera-holding products are on the market:
grips, stabilizers, stocks, etc. -- indicates that a lot of people wish that cameras
were easier to hold.
In truth, most cameras aren't designed with ergnomics in mind. The traditional
camera shape goes back to the Leica 1: a rectangular box with rounded ends and
a lens on the front. The rounded ends were for the film reel and the take-up reel.
By the 1960s, the SLR shape had gelled: like a rangefinder, but bigger and
with a pyramid on top.
Now DSLRs put a battery pack where one of the reels used to go.
The only concession to human anatomy is that the grip area has gotten larger.
Cameras are much easier to use if you cut off your nose. Then you
can sight using either eye. Just a "tip".
A grip need not just be a grip. It can also do on... (