I don't have a Minolta Auto Meter V F. But if it's like my Minolta Auto Meter IV F, to measure reflective light, you need a "reflected-light attachment" which is a simple piece of black plastic, with a hole in the center. The reflected-light attachment is included with the meter.

I also have a 5-degree viewfinder, but it costs extra, and may be difficult to find.

You can download the manual from here.