Gun Convergence/Harmonization

[Bert_Foster]

When you set the Convergence/Harmonization does this apply in both the Horizontal and Vertical planes ?

 

Horizontal is easily understood simply the distance to where the Gun Bore Lines intersect.

Vertical - Does this setting then also account for gravity drop at this range ?

[ACG_daffy_]

No, the trajectory isn't changed.  A bullet is a bullet...regardless of how the barrels are adjusted on the air frame.  The convergence is the distance at which, like you said, the trajectories should cross or be at their closes separation for maximum effect.  You can set your convergence for 500 meters...like I do on the IL2 for strafing, but you'll still need to compensate with adjusting the nose of your aircraft for the distance....I may have butchered that reply...but maybe it made some sense!!

[Dakpilot]

Pretty sure it is horizontal and vertical

 

easily tested with dissimilar weapon aircraft such as FW190 or Bf 109 with gunpods

 

Cheers Dakpilot

[216th_Jordan]

Yes convergence works in both vertical and horizontal.

[1Sascha]

According to the manual for the BK 3,7, those guns were harmonized to 1000 meters "Visierschuss" (vertical) and 400 meters "Kreuzung" (horizontal).
 
http://www.deutscheluftwaffe.de/archiv/Dokumente/ABC/b/Bordwaffen/Bordkanonen/Bordkanone37cm/Text/Ju87GTeil12ABK/Ju%2087%20G-2%20Teil%2012%20A%20BK%2043.pdf
 
Pages 20 and 21 on the pdf have the relevant info and graphs.
 
By chance, I had already used 400m as my in-game convergence for those guns and decided to check if vertical harmonization was a factor in game. It *seems* to me that they are indeed set to 1000 meters in the game, since with in-game convergence set to 400m I could still reliably hit targets at precisely 1000m (easy to check range, using ground icons). However: I am not sure if this was simply a coincidence and whether the in-game convergence sets only horizontal, both horizontal and vertical or some form of combination of the two.
 
S.

Edited July 15, 2016 by 1Sascha

[Aap]

 

 

According to the manual for the BK 3,7, those guns were harmonized to 1000 meters "Visierschuss" (vertical) and 400 meters "Kreuzung" (horizontal).  

 

You are misreading it a bit. Vertical convergence is set at 375 meters, it just happens that the projectile would be at the same line again at 1000 meters. It would not make much sense to set horizontal and vertical convergences to different distances, as it would make aiming more difficult. In this case the difference of horizontal and vertical convergences (400 m and 375 m) are a bit different, because Stukas did not attack ground targets horizontally but were diving towards them.

 

I am a bit surprised that in BOS you can't set the convergences of your standard guns and gunpods to different distances. That was possible even in the old IL2, not to mention CloD, where you can set every gun's horizontal and vertical convergences separately.

[curiousGamblerr]

Yeah two great suggestions above!

 

I could live without Chief's, although it would be real nice, but setting my MGs and cannons differently as Kemp described would be huge. I forgot about 1946 letting you do that.

[Yogiflight]

Sorry Kemp, but Sascha is correct. You can clearly read it in the instruction, that the guns are set to 1000m. But it happens, that the projectiles cross the sightline the first time at 375m. This is with all the other weapons the same. The nosecannons of the 109s, for example, where set to 400m, but crossed the sightline, the first time at 125m, so the projectiles were in the distances the pilots were shooting, above the sightline and therefore clearly to see.

[II/JG17_HerrMurf]

Convergence was a very hot topic in EA. The convergence is set for both horizontal and vertical with the slider. All guns are harmonized to a particular point in space. This was a DEV decision and although ahistorical is an excellent compromise for all of the various nation's ideas of how to set a multitude of different weapons, calibers and convergence points. It was discussed ad nauseum and you can find the various threads with the search function if you want to view them.

Edited July 15, 2016 by [LBS]HerrMurf

[MadisonV44]

Both Horizontal and Vertical are combined.

As a result depending on plane and armament some are tight and close to laser, others have loose/ curved effect (on the vertical plan) and are more difficult to aim at distance.    

[1Sascha]

Sorry Kemp, but Sascha is correct. You can clearly read it in the instruction, that the guns are set to 1000m. But it happens, that the projectiles cross the sightline the first time at 375m. This is with all the other weapons the same. The nosecannons of the 109s, for example, where set to 400m, but crossed the sightline, the first time at 125m, so the projectiles were in the distances the pilots were shooting, above the sightline and therefore clearly to see.

 

That's how I read it, too.

 

Page 20 clearly states

Justierung: Visierschuss 1000m - Kreuzung 400m (adjustment/harmonization: 1000m vertical/400m horizontal)

 

Page 21 states:

Erster Schnittpunkt der Geschossflugbahn mit der Visierlinie: 375m, zweiter bei 1000m. (first intersection of projectile's flight-path with sighting line at 375, second at 1000m). Adjusting the vertical setting to 1000m simply happened to produce the first "crossover" at 375m due the ballistics of the gun and its ammo.

 

And from the gun's in-game performance in the anti-tank-role I can totally understand why they chose 1000m. Getting within less than 400m of a tank to deliver your shells would be pretty scary, even in a simulation. I usually fired around 500m with those things during my first runs... but 1000m does seem to work just as well and it is a lot safer.. :D

[Dakpilot]

Not sure, but 1000M does not correlate with many pilot 'anecdotes' regarding engaging ground targets (Rudel for example)

 

Cheers Dakpilot

[Yogiflight]

The reason, why they adjusted the guns to 1000m is not because they wanted to shoot from this distance, but because they needed the crossing at around 400m. Kemp was right in what he wanted to say, that they shot on shorter distances. What I wanted to point out is that the adjusting was not to that distance.

From 1000m you hardly will hit a tank and you definitely won´t penetrate the armor of a T34, from no angle and no side. But you simply can not adjust the 37mm guns of the Ju87 to 400m, because they are simply to far below the gunsight.

[II/JG17_HerrMurf]

Huh, I hadn't thought of the mechanical offset aspect with the low slung guns.

[1Sascha]

The reason, why they adjusted the guns to 1000m is not because they wanted to shoot from this distance, but because they needed the crossing at around 400m. Kemp was right in what he wanted to say, that they shot on shorter distances. What I wanted to point out is that the adjusting was not to that distance.

From 1000m you hardly will hit a tank and you definitely won´t penetrate the armor of a T34, from no angle and no side. But you simply can not adjust the 37mm guns of the Ju87 to 400m, because they are simply to far below the gunsight.

 

In fairness, that graph makes the 3,7's trajectory look much worse than it actually is. X-axis is in hundreds of meters, Y-axis is in centimeters. And while the sighting line is 2 meters/200 cm above the gun's "boresight line", the highest point of the shell's path above the sighting line is only 67centimeters at 700m. Which isn't all that bad, considering the size of targets we're talking about here. When testing AT-gun performance in training, the German army used targets of 2.5x2meters to check hit probability vs enemy tanks. Meaning that if you take those dimensions, aiming for/shooting at the center of the target would still give you a hit even at 700m where the projectile is at its furthest from the sighting line.

 

I also wonder if the way they harmonized the gun had something to do with them wanting to "lob" the shells onto the upper armor of the tanks. Given the penetration-performance of the earlier ammo (mentioned, here: http://www.deutscheluftwaffe.de/archiv/Dokumente/ABC/b/Bordwaffen/Bordkanonen/Bordkanone37cm/bordkanone37.html#Technische%20Daten)you wouldn't have much luck trying to penetrate anywhere but on the thinnest parts of a T-34 anyway. I mean: 58mm@60° and 100m isn't all that great versus the T-34's sloped hull armor. The improved ammo supposedly did achieve 120mm, but that too is at 100m - and I very much doubt that they could get *this* close on their firing runs. And I do seem to recall reading that Rudel for example would specifically aim for the upper armor (turret or engine deck) which was usually the weakest part of all tanks.

[JtD]

Since the ground attack aircraft usually attacked in a dive, the sloped armour of the T-34 worked somewhat against it in these scenarios. In a 30° dive the 37mm ammo would penetrate all hull armour of a T-34 from about 500m out. Side armour and rear armour from further away. Additionally, the turret was vulnerable, even though the increased thickness of the /85 turret gave improved protection.

 

Lobbing shots works at artillery ranges, not at direct fire ranges of aircraft guns. Angles of 0.5° and such don't really help.

[MiloMorai]