By Tony Gondola

To help you understand why this can be a problem let's go back to basic principals. In a real aircraft the outside world is spread all around you in natural perspective, all framed by the cockpit windows. Perception of speed, rates, angles and distance are the result of a lifetime of seeing and dealing with the real world within the framework of normal human vision. Now imagine trying to fly your trusty 172 while wearing a pair of binoculars turned back to front. Now suddenly, everything your brain knows about angles, rates and distances is thrown out of whack. The brain is amazingly adaptable so with practice you can learn to adjust but it will never feel really right. This is exactly what you're doing when you fly using wide viewing angles in MSFS or any other flight sim for that matter. If you've ever had that feeling of the runway suddenly rushing towards you in the last 5 to 10 seconds before landing, are having a hard time tracking the runway centerline or just can't find your way around the pattern with any accuracy, incorrect FOV could be to blame.

To better understand why this is a problem here's a set of runway sight pictures taken at exactly the same moment but at different FOVs. The set on the left are at 1X, the set on the right are at 0.50X

The critical thing to remember is that changing FOV isn't just making the images larger or smaller, it's also changing the perspective relative to what you would see with normal vision. Notice in the last image set how much further away the far end of the runway appears relative to the 1X view. In general, wide angle images will make objects that are very close to the viewpoint appear larger while far off objects will appear smaller relative to what would be seen at a normal viewing angle at that same distance. This is an effect that's well known to photographers and film makers who can use it to make far off mountains seem huge and close, compress a crowd scene or put a larger then life nose on a person's face by working very close with a wide angle lens.

Changing FOV also changes your perception of rates and speed. Any given angle will be smaller on the screen as the FOV get's wider. If you have an aircraft that's slightly unstable in pitch it will seem less so at wide viewing angles. Inversely it can make a stable aircraft like a 172 seem to be too steady and sluggish in it's reactions. The actual movement in pitch in terms of degrees per second is of course unchanged but the perception of that movement will be less when viewed at wide angle settings because the motion on the screen will be less.

At this point you might be asking yourself "ok, I can see and understand the difference but what's normal?" The answer to that is going to be slightly different for each user depending on their setup but the principal behind it is very simple. The first step is to start thinking of your screen as a window onto a real world, just as in a real aircraft. Once you accept that then the rest is just simple geometry. Here's an example:

A zoom setting of 1.0X in MSFS works out to an angle of 45 deg. To find the zoom setting that exactly matches your true FOV simply divide the 1X angle by your true FOV. In my case that works out to a corrected zoom setting in MSFS of 1.17X (to keep things simple I just use 1.0X). In X Plane simply set you angle directly as calculated.

The surprising thing here is that when working with typical screen sizes and viewing distances, the true FOVs are shockingly narrow but that's the true situation that we have to deal with. This is in fact what you would see in a real airplane with a window at that size and distance. The only way to get wider images that are in correct perspective is to work closer to your screen or get a larger one, just as you would have to move closer to the window or get a larger one installed to get a wider view in the real aircraft. If nothing else this really points out the value of upgrading to multiple monitors or short of that, going with as large a monitor as you can afford or have desk space for.

The bottom line here is that if you're going to treat you monitor as a window then there's only one correct zoom setting for any given screen size and viewing distance. I would encourage you to work this out for your own system and see how it works for you. In my own case it has made landings more precise and made flying the pattern, even at a new airport a lot easier. Because my angle is so close to 1X everything stays in it's expected place as I clock around to the forward left, left and back left views that are so critical in determining position in the pattern. Once at altitude and setup for cruise I'll feel free to crank the settings up wide to watch the scenery go by but for the critical phases of pattern, landing and takeoff, working at the proper FOV makes for me a least, a world of difference.....give it a try!