Light Meter for portrait shoots

Is it pratical to use light meter for outdoor potraits shoots?

Also Is it acccurate it I measure the incident light at my position? Can I assume if it's open space the lighting would be the same?

Does the measurement is accurate if I stretch my hand while holding the light meter and get the reading instead of placing the lightmeter to the face of the model?

Can I just measure once and continue to shoot while the model can freely move from here and there from the original measurement spot(provided she doesn't move too far)?

In all of these case an average metering light meter mode is more that sufficient,right?

Yes, with portraits you're usually not really rushed. You have to put the raised dome where the face is, no idea what you mean about extending your hand, though whatever floats your boat. So long as the subject stays under the same lighting conditions you don't have to remeter - watch your histogram.

A good meter is the Sekonic L-358.

thanks for your tips. Anyway what I mean is. What if I'm too lazy go over the model location and meter her face. Say I I meter from the place where I stood. Is it accurate?

My worry is in outdoor the lighting would change without I realizing it and is not like the studio whereby the lighting is never get changed.

Would I be in a situation like I've to measure the incident light every 10 min or so if I feel sudden shift of the sun or cloud? If that's the case this would be very annoying.

Won''t be bracketing is more convinience?

Also is it practical and wise option to opt for a light meter for outdoor shoots? Nowaday we can do bracket and the histogram help to determine correct exposure.

Shoot in Av with partial metering, EC+1 on her face, then you don't have to move. Transfer the settings to manual mode if you want. No point having an incident meter if you don't use it. You can get light meters that have a partial or spot meter function, but they offer no advantage over your camera except bragging rights to camera nerds.