I think you may have meant Auto Meter IV 4 Not VI 6. Next, are you using the proper reflective light disk attachment in place of the incident sphere? If not you will not get the correct reflective reading no matter what.

Also, You have a dial in the battery compartment to adjust up or down 6 stops for compensation.

Besides the little reflective disk that should have come with the Auto meter IV you could also use one of the 5 or 10 % spot attachments for reflective metering. This will help you get more accurate reflective readings from a distance which can help with landscape readings.