On the Nikon D3200 you can swap out the viewfinder's exposure meter with a rangefinder, which uses a similar, meter-like display, as shown in the following figure, to indicate whether focus is set on the object in the selected focus point. If bars appear to the left of the 0, as shown in the left example in the figure, focus is set in front of the subject; if the bars are to the right, as in the middle example, focus is slightly behind the subject. The more bars you see, the greater the focusing error. As you twist the focusing ring, the rangefinder updates to help you get focus on track. When you see a single bar on either side of the 0, you’re good to go.
Before you activate this feature, there are a few issues to point out:
You can use the rangefinder in any exposure mode except M (manual exposure). In M mode, the viewfinder always displays the exposure meter.
In the other exposure modes, you can continue to view the exposure meter in the Information display, even with the rangefinder enabled. (Remember, the meter only appears in P, S, and A modes if the camera anticipates an exposure problem.)
Your lens must offer a maximum aperture (f-stop number) of f/5.6 or lower. The kit lens sold with the D3200 meets this qualification.
With subjects that confuse the camera’s autofocus system, the rangefinder may not work well either; it’s based on the same system. If the system can’t find the focusing target, you see the rangefinder display shown on the right in the previous figure.
The rangefinder is automatically replaced by the normal exposure meter if you switch back to autofocusing, but reappears when you return to manual focus.
If you want to try the rangefinder, head for Setup menu and change the Rangefinder option from Off to On, as shown in the following figure.
