Havoc at approximately 1.1km (zoomed view)
Airplane Icons and Visibility
This page will attempt to answer such perplexing questions such as why the icons in WW2OL work the way they do, and why there seems to be two levels of "magnification" to views, and gunsights.
Vision in WW2OL attempts to mirror human vision in several ways. A computer screen can never succeed in matching what a real human Mk 1 eyeball can do. It is of limited resolution, and limited field of view. Most people don't suffer from tunnel vision, thus they have peripheral vision to work with. However, we as humans can focus on the center of our vision and pick out extra detail not visible in the periphery. This is the fundamental reason for the two different zoom modes.
Most gameplay occurs in the "general" mode, which represents a non-focused view. This is an area of about 90 degrees in the game (left to right). The view system lets you look around and change the center of this view, but in general, it is supposed to represent what a human would see when not focused in some direction. The second step, the "zoomed in" view is 45 degrees. This is what was determined to be a 1:1 view for the human eye, where what you see in the game is approximately what you'd see in the center of your view. However, you're field of view is considerably restricted, thus this view is typically limited to "focus" situations, like when you're looking through a gunsight.
Scoped gunsights work similarly to general viewing. There are two aspects of a scoped sight, the field of view, and the magnification. The magnification makes things bigger, the field of view dictates how much stuff you see at that magnifcation. Magnification is modeled in the game as just that, things in the image appears bigger. Stuff viewed through a 2x gunsight, appears 2x their actual size if you viewed it without the sight. The field of view is represented by the black border to your view. This is the physical limit, off-axis, that you can see with the gunsight. Since some gunsights have fairly wide fields of view (greater thatn 50 degrees), we have adopted the 2 step "zoom", that works just like when looking around without a scope. The first step is the general "looking around" mode, the second is the focused look, where you have maximum Mk I Eyeball clarity. As far as I know, all of the scopes in WW2OL were fixed to one magnification in real life. The reason we have two is to help overcome the limitations of the monitor. The second "zoom" step is considered 1.0x magnification in the game, while the first is more of a 0.5x magnification.
However, even with the setup described above, real life pilots can often see much better than you can see in the game. They were selected for good vision, trained for many hours to recognize airplanes, and have good depth perception (depth perception is non-existant in WW2OL due to the limitations of the computer monitor). In the special case of airplanes, an aid has been provided to help match what a real pilot would see.
In other simulations, the icon for an airplane would often show the range as a digital readout, and a label showing you what the airplane was (such as Spitfire or Bf109). This is not how real eyes work. Eyes are really good at telling relative distance, not absolute distance. You can see that A is further away than B, but not that B is 232.3457642 meters away. This phenomenon was experienced on the Apollo Moon missions when objects would seem to be small and relatively close, yet they were actually big and far. Entire mountains can appear in Apollo pictures as mere hills, and the Astronauts experienced this almost to the same degree that we do when looking at the pictures. The human eye is also good at judging closure rate. Anyone who drives knows about the eye's ability to sense when they're closing on the car in front (time to start thinking about slowing down), or if the car in front is pulling away (and thus it's safe to step on the gas pedal).
Unfortunately, neither relative distance nor closure rate are easily perceived on Computer monitors. Since closure rate and relative position are so important in air combat, WW2OL provides an icon system to give the player that aid. The longer the circle is, the further away the target is. If the circle is shrinking, the target is getting closer. If the circle is growing, the target is getting farther away. If the circle doesn't change, then you are neither gaining nor losing distance.
However, in real life, the further away the object is, the harder it is to judge relative distance and closure rate. This is modeled by the scale factor on the circle. The curve used is a distance squared curve, meaning that something twice as far has half the effect. Thus, a distance change or movement at 3km on the circle will be much harder to tell than at 750m. In addition, it is harder to tell that two aircraft are 100m apart at 3km than 300m.
The circle in WW2OL is scaled to 4km. A full circle indicates the target is 4km away. Half a circle indicates 1km, and a quarter circle is 250m. Everything else follows the distance squared rule. You double the circle distance from 1/4 to 1/2, and the real-world distance is quadrupled. You double it again to a full circle, and it's quadrupled again. The net effect is that, just like real life, it's easier to tell closure and relative distance for closer objects. Just like it's easier to maintain a certain distance from a car you're following when you're closer than further away (this partially helps explain tailgaters). Absolute distance is difficult to judge, just like real life. A good rule of thumb is that it's best not to shoot at someone unless they're less than a quarter circle away.
Now a real pilot is going to have a lot more trouble telling what someone is doing when he snaps his eyes to them than when he's been staring for a bit. This is modelled in WW2OL by the fade-in system. When an airplane first appears in view, it has no icon. The icon fades in with time. This means that when you're tracking someone with your camera views, you get a good solid icon, but if you glance away or lose them while doing a maneuver, you cannot rely upon the icon to reacquire them, unless you happen to be looking in their direction for a few seconds. In addition, targets further away are generally harder to spot, so they are faded out more, and the further they are the longer they take to "reacquire".
Airplane names are used to overcome another limitation of the computer monitor. At distances where a reasonably trained pilot would recognize an airplane, you will get the general type and therefore whether they're friendly or not. Just like with ground troops, you see names of friendlies (unless you've toggled the icon mode). However, while a P38 is easily distinguishable from a Bf109, two Spitfires are nearly impossible to tell apart until they're very close (in which case, you shouldn't be flying by the icons anyway). This is why Spitfires show up as "Spit" and not "SpitV", for example.
The name is placed below the airplane on the display. In addition, the orientation of the circle is such that when you are very close (close enough to do a Turn 'n' Burn deflection shot), the circle arc is very small and below the airplane. Other flight simulators placed the name above the airplane, which meant that even if the target was below the nose (and not visible), you could use the icon as an aiming reference. In WW2OL this is almost impossible because the range circle and name are even further below the aircraft when pulling those kind of deflection shots, thus the icon does not help you in shooting.
One may wonder why there are no icons for ground units (except for friendly aircraft). The answer is because we didn't want icons, period. Air combat, however, is much more hampered by the limitations of the computer monitor, and there is no easy way to incorporate a 1:1 45-degree field of view mode in the look-around system without ruining peripheral vision (try flying with just the zoomed gunsight view sometime). Maybe with the new mouse-look system CRS might add a "zoom" button to give you 1.0x magnification. But as it stood when the bulk of the game was written, there was a need to give the airplane fliers a little extra help. On the ground, virtually every ground unit has a 1:1 mode. Infantry have a gunsight zoom. Tanks have binoculars and gunsights. In addition, you can't hide in air to air combat (except using clouds, which obscure the icons anyway), and ground units don't move rapidly vs the ground like aircraft do. It becomes impossible to hide if you have a glaring "I'm here!" icon above you when you're in some bushes sneaking up on someone. In addition, creating a system that accurately determines whether you can be seen (how many leaves cover you? Is that berm covering 25% of you?) is very difficult, and it is even more difficult to write one that's fair 99% of the time. As a result, the decision was made to not have icons for enemy ground units, but to use the above system for aircraft.