With the Vue you can choose SLP, altimeter setting, or none, which is raw, don't want that. All you need is the height of your console above sea level (try to be accurate within at least 10 ft or so), enter that value into the console and select which reduction you prefer (REDUCE BAR NOAA, which is SLP, or ALT SET). The console does all the work after that, no outside comparison is needed. You can fine tune it further if desired, but I find it's spot on without it.