Not! A light meter is an indispensable tool if you want to ace your exposures first time.
Take this scene (taken, incidentally, amidst a whole bunch of naked people):
That meter is well exposed. Perfectly, in fact. Values were 100 ISO, f/5.6 at 1/50th second.
How? By reading the values off the incident light meter (a meter you hold where the subject will be):
- Set the meter to ambient (not flash) metering
- Move the ball out
- Select the camera’s ISO and the aperture you want
- Hold the meter where the subject will be.
- Click and read the value for shutter.
- Set those values on your camera
With the camera’s built-in light meter, however, the exposure came out like this, since the light background was also read by the meter:
That’s nice for the background, but if the meter is the subject, this exposure is all wrong – 2 stops too dark (the camera thought 1/200th was the correct shutter speed). You would now have to adjust the exposure manually, or instead aim your camera, set to spot metering, at a gray card held there. Which is less convenient.
And that is why light meters are far from old hat. Pros use them all the time, even as ambient light meters as here.