RAF Gun convergence to 100m - DO NOT DO IT!

[92 Sqn. Philstyle (QJ-P)]

Hi guys,

Moved my convergence to 100m last night to see what effect it would have.

It's OK-ish when you are in a really close turning fight at extremely high angles of deflection (i.e. when you can see the top-down profile of his aircraft in your sights at close range) but apart from that, most of the bullets converge way to early, and simply fly past either side of the target, especially when firing from his 6-O'clock position.

I'm going to continue practicing with this convergence, but it will require getting far, far closer than usual, and probably much close than 100m... I'll keep you all updated ;)

[ATAG_Snapper]

Good post, PStyle! :thumbsup:

For my fighting/shooting style, I've been having good results with my elevation/convergence set at 150/150 meters, and my gunsight convergence set to 170 yards, since I tend to get very close in to my target. If I get much closer than my 170 yard (150 meter) convergence I hold off to one side, per the video I shot yesterday:


http://vimeo.com/52928231


http://vimeo.com/52928231

[Ivank]

A slightly different take on convergence concentrating on the fighter v fighter engagement.... Go for a greater convergence range.

Back in the last decade A gent arrived on the IL2 scene who was deadly with the 109G2 and external gun pods .... He was the Mr X of his time. He was so deadly he used external gunpods as his default loadout and accepted the weight/drag penalty. He then revealed that his basic convergence setting (Horizontal) was 600M ! He also explained it very well.

The logic goes something like this. We are not all surgeons and cant estimate ranges accurately (even with the RAF GM2 sight with correct range and wingspan ... since the average DF is so dynamic and Angle Off and Heading crossing angle tend to reduce the accuracy of the sight settings). Given our fighter wingspan is roughly 10-12m (as is the bandit) then if Parallel harmonisation was used all bullet streams would be contained within the wingspan. Clearly some convergence is required ... but how much ? Perhaps a longer range is best as this would cater for crap range estimation (the norm) and still have converging streams. Super close convergence are ONLY of any use AT and or BELOW the convergence range. Past the convergence range the bullet streams (and therefore bullet density) are widely diverging. The closer the convergence the worse the issue.

So having converging bullet streams over a GREATER range provides a means to cater for the infinite variables we deal with on every gun shot. A longer convergence setting also gives you a better chance on actually getting hits on Snapshots ... a very frequent event.
Snapshooting with a point harmonisation is not practical. A greater convergence setting also reduces the amount of bullet stream divergence past the convergence range ... helps if your range assessment is out.

As to vertical adjustment. Traditionally we all underestimate the lead required by huge amounts (forget about gravity drop... at the ranges we fire its minimal in comparison to the size of the target). In addition its only accurate if you are flying exactly wings level (Any bank brings in an error). So use (imo) a vertical setting to improve your chances by building in an artificial extra lead requirement. Dedciding how much is personal. Of couse in 1G direct 6 shots you will need to take this in to account.

Taking this line of thought further it could be argued that the closer in to the centreline your guns are the GREATER the Harmonisation range. So in the case of the the BF110 and MG on the 109 maybe set them to the maximum possible range to get a long thin hardly cpnverging bullet stream. For he Wing guns bring them in to say converge at 600m. With the Spits a similar but progressive arrangement could be argued for variable convergence with the longer ranges starting with the in board guns.

Now if you are a surgeon and can guarantee your range, have perfect Angle Off and lead prediction (or are just going bomber killing) then there is no doubt the close in Point harmonisation is the way to go. BUT are you that good and can you guarantee achieving the required firing envelope every time ?

So at the moment my settings are:

RAF types Vert 200m, Horiz 600m. I set the sight to 230ft, Wingspan 38ft.
Luftwaffe types Fuselage guns 800m, Wing cannons 600m, Vert 200m

[71st_AH_Code_E]

Interesting post Ivan. This is something I'm definitely willing to try. Especially a high vertical convergence. I've been thinking of doing that for a while and always forget to. :doh:

Your argument definitely makes sense. I'm sure not everyone agrees, but then again, not everyone flies/shoots the same either. This would make shooting with "The Force" easier, like JTDawg is always telling me to do. :PP

[ATAG_Snapper]

A slightly different take on convergence concentrating on the fighter v fighter engagement.... Go for a greater convergence range.

Back in the last decade A gent arrived on the IL2 scene who was deadly with the 109G2 and external gun pods .... He was the Mr X of his time. He was so deadly he used external gunpods as his default loadout and accepted the weight/drag penalty. He then revealed that his basic convergence setting (Horizontal) was 600M ! He also explained it very well.

The logic goes something like this. We are not all surgeons and cant estimate ranges accurately (even with the RAF GM2 sight with correct range and wingspan ... since the average DF is so dynamic and Angle Off and Heading crossing angle tend to reduce the accuracy of the sight settings). Given our fighter wingspan is roughly 10-12m (as is the bandit) then if Parallel harmonisation was used all bullet streams would be contained within the wingspan. Clearly some convergence is required ... but how much ? Perhaps a longer range is best as this would cater for crap range estimation (the norm) and still have converging streams. Super close convergence are ONLY of any use AT and or BELOW the convergence range. Past the convergence range the bullet streams (and therefore bullet density) are widely diverging. The closer the convergence the worse the issue.

So having converging bullet streams over a GREATER range provides a means to cater for the infinite variables we deal with on every gun shot. A longer convergence setting also gives you a better chance on actually getting hits on Snapshots ... a very frequent event.
Snapshooting with a point harmonisation is not practical. A greater convergence setting also reduces the amount of bullet stream divergence past the convergence range ... helps if your range assessment is out.

As to vertical adjustment. Traditionally we all underestimate the lead required by huge amounts (forget about gravity drop... at the ranges we fire its minimal in comparison to the size of the target). In addition its only accurate if you are flying exactly wings level (Any bank brings in an error). So use (imo) a vertical setting to improve your chances by building in an artificial extra lead requirement. Dedciding how much is personal. Of couse in 1G direct 6 shots you will need to take this in to account.

Taking this line of thought further it could be argued that the closer in to the centreline your guns are the GREATER the Harmonisation range. So in the case of the the BF110 and MG on the 109 maybe set them to the maximum possible range to get a long thin hardly cpnverging bullet stream. For he Wing guns bring them in to say converge at 600m. With the Spits a similar but progressive arrangement could be argued for variable convergence with the longer ranges starting with the in board guns.

Now if you are a surgeon and can guarantee your range, have perfect Angle Off and lead prediction (or are just going bomber killing) then there is no doubt the close in Point harmonisation is the way to go. BUT are you that good and can you guarantee achieving the required firing envelope every time ?

So at the moment my settings are:

RAF types Vert 200m, Horiz 600m. I set the sight to 230ft, Wingspan 38ft.
Luftwaffe types Fuselage guns 800m, Wing cannons 600m, Vert 200m

This sounds like something worth trying. If I understand your post correctly, I might want to try setting the Spitfire's inboard guns at 600m conv, then each successive outboard pair I would decrease the convergence by roughly equal increments ie guns 2 & 7 - 450m, 3 & 6 - 320m, and finally 4 & 5 - 200m. Elevation would be set at 200m for all guns. Gunsight set to 230 yards.

To confuse the issue I believe the elevation and convergence settings ingame are still reversed....:beaten:

Will give this a try -- it's easy enough to do. Thanks for the input!

[71st_AH_Code_E]

From my minimal testing, I do believe you're right about horizontal and vertical being reversed in game.

[Ivank]

I am yet to be convinced on the reversal vertical as against horizontal but if it is the case then entering the data in Reverse Polish notation is the go :)

Yes Snapper that is the suggestion.

[ATAG_JTDawg]

Interesting post Ivan. This is something I'm definitely willing to try. Especially a high vertical convergence. I've been thinking of doing that for a while and always forget to. :doh:

Your argument definitely makes sense. I'm sure not everyone agrees, but then again, not everyone flies/shoots the same either. This would make shooting with "The Force" easier, like JTDawg is always telling me to do. :PP

:hypnotized: I will stick with THE FORCE roflmao As the Force works for me , When closing my eyes , an feeling where the 109 is in my dark grey dura cell . pulling the trigger , open eyes fast , shahzam 109 venting , repeat process until down

[Doc]

:hypnotized: I will stick with THE FORCE roflmao As the Force works for me , When closing my eyes , an feeling where the 109 is in my dark grey dura cell . pulling the trigger , open eyes fast , shahzam 109 venting , repeat process until down


roflmao

[Ivank]

It would seem that this Vertical and Horizontal convergence issue is a language localistion issue. The German version has the top box as Horizontal and the lower box as Vertical .... i.e. the opposite to the English. I think its the same story with the Russian version. So we really need to get as examples of this from all language versions if the Sim to put it to bed once and for all. I have started a thread on 1C:

http://forum.1cpublishing.eu/showthread.php?t=35764

English Loadout screen:

http://i40.photobucket.com/albums/e215/zulu64/Clod_Loadout.jpg

German Loadout screen

http://i40.photobucket.com/albums/e215/zulu64/germanloadout.jpg


So far it seems it is reversed for English versions of the game.
Update Spanish is afflicted as well.

[92 Sqn. Philstyle (QJ-P)]

It would seem that this Vertical and Horizontal convergence issue is a language localistion issue. The German version has the top box as Horizontal and the lower box as Vertical .... i.e. the opposite to the English. I think its the same story with the Russian version. So we really need to get as examples of this from all language versions if the Sim to put it to bed once and for all. I have started a thread on 1C:
So far it seems it is reversed for English versions of the game.

IvanK - I saw your thread on 1c. Very good idea.
I think you might have got to the bottom of this issue.

I have the English version (no screenshot, I'm at work right now) and I'm 100% sure that my convergence menus are reversed/wrong (i.e. that the setting that states "horizontal" actually modifies the vertical convergence of the weapons).

[Fried]

Some great posts guys and some real food for thought from Ivank, thank you.

As far as the hor vs vert discussion, they dont make it easy for us do they, hope you can get to the bottom of this once and for all :thumbsup:

[Ivank]

From responses in the 1C thread on this I think we can confirm in the ENGLISH and SPANISH localisations of CLOD the convergence setting labels are opposite. So in these versions of the game :

The Top Box labelled VERT CONV actually sets HORIZONTAL CONVERGENCE
The Lower Box labelled HORIZ CONVactually sets the VERTICAL CONVERGENCE

Looking in the User.ini file according to ATAROS in the convergence settings the first value is Horizontal the second value is Vertical.

I am using 600M Horizontal and 235 Vertical. So the Top box is set to 600 and the bottom box is set to 235 the resulting entry in user.ini looks like this:


[Aircraft.SpitfireMkIa]
conv _Gun03 Gun.Browning303MkII 600 235
conv _Gun06 Gun.Browning303MkII 600 235

[ATAG_Torian]

I am using 600M Horizontal and 235 Vertical. So the Top box is set to 600 and the bottom box is set to 235 the resulting entry in user.ini looks like this:
[Aircraft.SpitfireMkIa]
conv _Gun03 Gun.Browning303MkII 600 235
conv _Gun06 Gun.Browning303MkII 600 235

Why set the vertical to 235 ? Doesn't that mean that at 600 the horizontal convergence would be well below your centre point on your gunsight? I could see some value in making the vertical greater than the horizontal but not the other way around. I don't know what the pros & cons are of vertical settings as we didn't have that option in IL2 1946. Be happy to be enlightened tho :idea:

[Ivank]

There is no magic in the vertical setting. 235 or in the 200 - 250 m range is close to the range I like to open fire at. This assumes I can judge the range right. Setting the range and wingspan on the RAF sight gives some help here (But also has some major limitations too) .So I am trying to get the Vertical correction set for my typical firing range (and G/Angle of Attack... see below) thats all. You develop your own sense of how much lead is typically required for the sight setting and engagement conditions you have. This just works for me.

WARNING NERD ALERT IF YOU PROCEED PASS THIS POINT :)

Mind you there is also a lot more to this itself if you look into it. Gravity Drop always operates in the true vertical. So any correction for GD is only really valid in straight and level flight. As the Bank angle goes up the error becomes greater. Other than shooting at sitting ducks or Bombers we are rarely shooting with 0 Bank. At the closer ranges (<250m) its to all intensive purposes negligible. Gravity Drop correction is the smallest factor in the fire control problem.

Of course you also need to allow for lead for target motion (The single largest lead factor requirement) and is applied in the targets plane of motion, and finally Trajectory shift the second largest lead factor requirement and in general acts in the same plane as lead for target motion). Lead for target motion is a function of bullet time of flight ..... i.e. how far does the target actually move from open fire to impact. So the greater the range the greater the lead required. Trajectory shift is a biggy and varies as a Function of Angle Of Attack (AOA) and Angle of Gunfire (AGF). AGF you have tweaked in your vertical convergence setting. WRT AOA technically your lead requirement increases as AOA increases.

Since both Lead and trajectory Shift operate in the same plane this is the biggest factor in Air to Air shooting, and one of the reasons we all tend to underestimate the lead requirement.

Trajectory Shift also exists in the lateral plane as well as a function of Slip/Skid and also as a function of your horizontal convergence setting ... i.e. how much you have "misaligned" your gun from the true fore aft axis of the aircraft. So if you really set close in horizontal convergence you are increasing Lateral trajectory shift. This though is kind of compensated for by the fact that you have the opposite occurring with guns on the other side. Anyway this actually will ALWAYS result in a slightly elliptical impact area rather than a nice point hit area. To a certain extent this favours a the further out rather than closer in horizontal convergence setting imo, though I guess there is some break even point here. We are talking small angles anyway so its pretty small anyway. The BIGGEST cause of lateral trajectory shift is slip or skid. Keep it balanced and smooth to get the most consistent solution.

So with all these complications it can be seen that pretty much every shot you take is actually a snapshot, all that varies is the range and crossing rate.

Trajectory Shift is also referred to (typically in the US) as velocity Jump.

[ATAG_JTDawg]

there is no magic in the vertical setting. 235 or in the 200 - 250 m range is close to the range i like to open fire at. This assumes i can judge the range right. Setting the range and wingspan on the raf sight gives some help here (but also has some major limitations too) .so i am trying to get the vertical correction set for my typical firing range (and g/angle of attack... See below) thats all. You develop your own sense of how much lead is typically required for the sight setting and engagement conditions you have. This just works for me.

warning nerd alert if you proceed pass this point :)

mind you there is also a lot more to this itself if you look into it. Gravity drop always operates in the true vertical. So any correction for gd is only really valid in straight and level flight. As the bank angle goes up the error becomes greater. Other than shooting at sitting ducks or bombers we are rarely shooting with 0 bank. At the closer ranges (<250m) its to all intensive purposes negligible. Gravity drop correction is the smallest factor in the fire control problem.

Of course you also need to allow for lead for target motion (the single largest lead factor requirement) and is applied in the targets plane of motion, and finally trajectory shift the second largest lead factor requirement and in general acts in the same plane as lead for target motion). Lead for target motion is a function of bullet time of flight ..... I.e. How far does the target actually move from open fire to impact. So the greater the range the greater the lead required. Trajectory shift is a biggy and varies as a function of angle of attack (aoa) and angle of gunfire (agf). Agf you have tweaked in your vertical convergence setting. Wrt aoa technically your lead requirement increases as aoa increases.

Since both lead and trajectory shift operate in the same plane this is the biggest factor in air to air shooting, and one of the reasons we all tend to underestimate the lead requirement.

Trajectory shift also exists in the lateral plane as well as a function of slip/skid and also as a function of your horizontal convergence setting ... I.e. How much you have "misaligned" your gun from the true fore aft axis of the aircraft. So if you really set close in horizontal convergence you are increasing lateral trajectory shift. This though is kind of compensated for by the fact that you have the opposite occurring with guns on the other side. Anyway this actually will always result in a slightly elliptical impact area rather than a nice point hit area. To a certain extent this favours a the further out rather than closer in horizontal convergence setting imo, though i guess there is some break even point here. We are talking small angles anyway so its pretty small anyway. The biggest cause of lateral trajectory shift is slip or skid. Keep it balanced and smooth to get the most consistent solution.

So with all these complications it can be seen that pretty much every shot you take is actually a snapshot, all that varies is the range and crossing rate.

Trajectory shift is also referred to (typically in the us) as velocity jump.

+1 the force

[ATAG_Snapper]

Another good thread over at 1C locked by Alpha: "This thread has nothing to do with convergences, just a GUI problem."

:doh:



It would seem that this Vertical and Horizontal convergence issue is a language localistion issue. The German version has the top box as Horizontal and the lower box as Vertical .... i.e. the opposite to the English. I think its the same story with the Russian version. So we really need to get as examples of this from all language versions if the Sim to put it to bed once and for all. I have started a thread on 1C:

http://forum.1cpublishing.eu/showthread.php?t=35764

English Loadout screen:

http://i40.photobucket.com/albums/e215/zulu64/Clod_Loadout.jpg

German Loadout screen

http://i40.photobucket.com/albums/e215/zulu64/germanloadout.jpg


So far it seems it is reversed for English versions of the game.
Update Spanish is afflicted as well.

[Ivank]

What is wrong with these Turkeys on the Banana forum !

[ATAG_Slipstream]

What is wrong with these Turkeys on the Banana forum !

That would officially make Alpha a headless Turkey.

[ATAG_Snapper]

I don't know why this thread was locked. Yes, it appeared to be simply a switch of horizontal conv vs elevation on the English GUI which the thread ascertained, but there was a lot of related discussion including screenshots of other language GUI of the same thing for comparison purposes. There were no nasty posts or trolls -- which could simply be deleted without closing the thread itself.

Who moderates the moderators over there? :beaten:

[Dutch]

I had a far better expression for 'Headless Turkey', which I utilised in a PM. Thus generating a further ban until 12th December.

Ah well. At least when I post here, I know I'm talking to rational Human Beings.

Even if I'm not so rational myself on occasions. Hic.

[92 Sqn. Philstyle (QJ-P)]

Another good thread over at 1C locked by Alpha: "This thread has nothing to do with convergences, just a GUI problem."
:doh:

RIGHT!

So we re-post the entire thread under the heading "GUI Problem - relating to convergence settings"