Mr Fox
30-05-2009, 01:13 PM
Convergence
I opened fire when the whole windshield was black with the enemy…at minimum range…it doesn’t matter what your angle is to hit or whether you are in a turn or any other maneuver.
—Erich Hartmann
352 victories
When novice pilots first loaded up IL-2 Sturmovik they were surprised to see that they could choose the convergence settings for machine guns and cannon, depending on the type of aircraft they would fly. What is convergence and why is it important?
http://i11.photobucket.com/albums/a198/glen73/fw190-converge.jpg
Convergence Setting
Convergence is the point at which shells fired from guns along a parallel axis meet at that distance in space. While many understand this, not all understand that convergence is set in both the vertical and horizontal planes, correcting for gravity.
Furthermore, convergence settings can be made individually for both cannon and machine guns. The default setting in IL-2 is 300 meters, which means that shells fired from the cannon or machine guns on the FW 190 will meet roughly at a point in space 300 meters ahead of the aircraft. In order to accomplish this, the guns are canted toward the center line of the aircraft and tilted slightly upwards.
Most commonly, guns that are set for air-to-air combat are set at 300m convergence and shorter, while guns that are set for air-to-ground combat are set at 400m and beyond.
The idea is to concentrate a bullet stream on the target at a given distance. Obviously, many forces will affect the flight of a given shell, so it is to the advantage of the shooter to minimize dispersion and concentrate fire power.
Most pilots select a convergence of around 200 meters, but some prefer even less. The novice should start about 220 meters and then work downwards from this base to find the greatest success. The point to remember is that convergence should be set to the range where you prefer to engage your target. Since the novice tends to fire early rather than late, it is best to start with a slightly long convergence setting rather than a short one.
Target at 200m
http://i11.photobucket.com/albums/a198/glen73/target1.jpg
Target at 100m
http://i11.photobucket.com/albums/a198/glen73/target2.jpg
Once you have set the convergence on your guns, you should engage when the target is within 20 meters of your preferred setting. Remember that as you close on the target beyond the convergence point the dispersion pattern of your shells will increase.
This raises two further questions: at what range will a given projectile have the greatest effect, and how do I know when my target is within a certain range?
Finding the Range to the Target
We’ll use IL-2 as our simulation of choice for demonstrating the concepts we will discuss here, because IL-2 has the most realistic model of air-to-air gunnery yet seen on the PC. Furthermore, the clarity of graphics will make it easier for you to determine your range to a given target at any time.
Target 210m
http://i11.photobucket.com/albums/a198/glen73/article1.jpg
The easiest way to determine the range to the target is to select icons ON in the game setup. An icon appears near your target that lists the target type and range. This way you can always tell your exact range to the target.
Icons give the player a great advantage. Furthermore, they allow the player to become familiar with estimating range based on target size. If you fly with icons on for twenty hours or more, when you turn them off you will have a very good idea of the range at which you are engaging.
The other way to determine the range to the target is to measure the target against the gun sight. We’ll use the gunsight in the Bf 109 for all measures from here on.
Target 100m
http://i11.photobucket.com/albums/a198/glen73/article2.jpg
In this second image you can see that the distance to the target is half that of the first image, being only 100 meters. Notice that the wingspan of the target at this range occupies all the left side of the gunsight plus half the right side, or three quarters of the total gunsight in the Bf 109.
Since the G model of the Bf 109 has a wingspan of 30 feet, we now know that the gunsight in the Bf 109 represents a span of forty feet at 100 meters. We’ll use this knowledge not only for estimating range, but also for estimating lead angles.
He 111 at 100m
http://i11.photobucket.com/albums/a198/glen73/article4.jpg
Even a fairly small bomber has a wingspan double that of the average fighter. The Ju-88 has a wingspan of 65 feet. At 100 meters it looks VERY large, occupying one and a half gunsights.
Now let’s go back to the original image, where the Bf 109 at 210 meters barely fills the circle in the middle of the gunsight. This will be our standard measure. You should not open fire until the target fills the center circle of the gunsight. The center circle measures roughly forty feet at 200 meters. We’ll use this knowledge to establish appropriate lead angle when firing.
Gunsight circle
http://i11.photobucket.com/albums/a198/glen73/article5.jpg
I opened fire when the whole windshield was black with the enemy…at minimum range…it doesn’t matter what your angle is to hit or whether you are in a turn or any other maneuver.
—Erich Hartmann
352 victories
When novice pilots first loaded up IL-2 Sturmovik they were surprised to see that they could choose the convergence settings for machine guns and cannon, depending on the type of aircraft they would fly. What is convergence and why is it important?
http://i11.photobucket.com/albums/a198/glen73/fw190-converge.jpg
Convergence Setting
Convergence is the point at which shells fired from guns along a parallel axis meet at that distance in space. While many understand this, not all understand that convergence is set in both the vertical and horizontal planes, correcting for gravity.
Furthermore, convergence settings can be made individually for both cannon and machine guns. The default setting in IL-2 is 300 meters, which means that shells fired from the cannon or machine guns on the FW 190 will meet roughly at a point in space 300 meters ahead of the aircraft. In order to accomplish this, the guns are canted toward the center line of the aircraft and tilted slightly upwards.
Most commonly, guns that are set for air-to-air combat are set at 300m convergence and shorter, while guns that are set for air-to-ground combat are set at 400m and beyond.
The idea is to concentrate a bullet stream on the target at a given distance. Obviously, many forces will affect the flight of a given shell, so it is to the advantage of the shooter to minimize dispersion and concentrate fire power.
Most pilots select a convergence of around 200 meters, but some prefer even less. The novice should start about 220 meters and then work downwards from this base to find the greatest success. The point to remember is that convergence should be set to the range where you prefer to engage your target. Since the novice tends to fire early rather than late, it is best to start with a slightly long convergence setting rather than a short one.
Target at 200m
http://i11.photobucket.com/albums/a198/glen73/target1.jpg
Target at 100m
http://i11.photobucket.com/albums/a198/glen73/target2.jpg
Once you have set the convergence on your guns, you should engage when the target is within 20 meters of your preferred setting. Remember that as you close on the target beyond the convergence point the dispersion pattern of your shells will increase.
This raises two further questions: at what range will a given projectile have the greatest effect, and how do I know when my target is within a certain range?
Finding the Range to the Target
We’ll use IL-2 as our simulation of choice for demonstrating the concepts we will discuss here, because IL-2 has the most realistic model of air-to-air gunnery yet seen on the PC. Furthermore, the clarity of graphics will make it easier for you to determine your range to a given target at any time.
Target 210m
http://i11.photobucket.com/albums/a198/glen73/article1.jpg
The easiest way to determine the range to the target is to select icons ON in the game setup. An icon appears near your target that lists the target type and range. This way you can always tell your exact range to the target.
Icons give the player a great advantage. Furthermore, they allow the player to become familiar with estimating range based on target size. If you fly with icons on for twenty hours or more, when you turn them off you will have a very good idea of the range at which you are engaging.
The other way to determine the range to the target is to measure the target against the gun sight. We’ll use the gunsight in the Bf 109 for all measures from here on.
Target 100m
http://i11.photobucket.com/albums/a198/glen73/article2.jpg
In this second image you can see that the distance to the target is half that of the first image, being only 100 meters. Notice that the wingspan of the target at this range occupies all the left side of the gunsight plus half the right side, or three quarters of the total gunsight in the Bf 109.
Since the G model of the Bf 109 has a wingspan of 30 feet, we now know that the gunsight in the Bf 109 represents a span of forty feet at 100 meters. We’ll use this knowledge not only for estimating range, but also for estimating lead angles.
He 111 at 100m
http://i11.photobucket.com/albums/a198/glen73/article4.jpg
Even a fairly small bomber has a wingspan double that of the average fighter. The Ju-88 has a wingspan of 65 feet. At 100 meters it looks VERY large, occupying one and a half gunsights.
Now let’s go back to the original image, where the Bf 109 at 210 meters barely fills the circle in the middle of the gunsight. This will be our standard measure. You should not open fire until the target fills the center circle of the gunsight. The center circle measures roughly forty feet at 200 meters. We’ll use this knowledge to establish appropriate lead angle when firing.
Gunsight circle
http://i11.photobucket.com/albums/a198/glen73/article5.jpg