Jump to content
ST_Catchov

FC gun convergence.

Recommended Posts

Is the FC gun convergence a load of bollocks? Does it make a difference? Does it even work?  Is it a useless by-product from the WWII modules? Is it supposed to measure horizontal and vertical convergence? 

 

I've tried everything between 150m and 500m and not noticed any appreciable difference. So I just sit at 200m and leave it at that.

 

What do you guys use and why? Looking at you @US93_Larner hehe ....

 

 

Share this post


Link to post
Share on other sites

I think it has no effect at all in FC. If you look at the default gunsight view and change the convergence numbers, firing from the runway there is no apparent difference to the tracer pattern relative to the pipper that I can see, nor is the position of the ring moved.  Do that with any of the WW2 planes and the vertical effect is very obvious, even with the planes with the guns in the nose - the 1000m setting pitches the tracers up relative to the pipper much more. 

 

Less sure about the horizontal since the guns are so close together, and natural dispersion makes it hard to see if the 100m setting spreads the shots out more at 1000m than the 1000m setting. I do not think it does, and at ranges of up to 300m it makes no difference.

  

  • Thanks 1

Share this post


Link to post
Share on other sites

I don’t think it does.

 

I had thought it might have been a solution to the SE5a’s guns shooting at the wrong angle, setting an ultra long convergence in order to lift the line of fire to the correct one, but regardless of convergence setting, within the limits available, it didn’t seem to change very much, if at all, so no I don’t think FC has any change in the vertical .  The only perceptable difference, to horizontal convergence, might be with the Dolphin wing guns, but trying to stay alive long enough, in a Dolphin, to see the effect makes it all a bit theoretical at best.

Share this post


Link to post
Share on other sites

With the guns being so close together, and the fact that you're not suppose to shoot until you're close..closer..closer yet - I just pick a number I find 'quite pleasing'.

 

S!

 

Someone tell the ai gunners about the close..closer.. bit. Thanks !

Share this post


Link to post
Share on other sites

It made a lot of difference in ROF. So I don't see any reason why it shouldn't be the same in FC.

 

Note: I am NOT saying it does work at all ;)

Share this post


Link to post
Share on other sites
5 hours ago, HagarTheHorrible said:

I don’t think it does.

 

I had thought it might have been a solution to the SE5a’s guns shooting at the wrong angle, setting an ultra long convergence in order to lift the line of fire to the correct one, but regardless of convergence setting, within the limits available, it didn’t seem to change very much, if at all, so no I don’t think FC has any change in the vertical .  The only perceptable difference, to horizontal convergence, might be with the Dolphin wing guns, but trying to stay alive long enough, in a Dolphin, to see the effect makes it all a bit theoretical at best.

 

You are right - with the Dolphin wing guns you can clearly see the difference in the horizontal convergence, although none in the vertical. You are allowed to test in QMB you know - it took less time than typing this post and I am sure your fellow MP flyers would not think it a betrayal.  

Share this post


Link to post
Share on other sites

It certainly changes vertically. It does in every other plane on the WW2 side so why would it not here? 

 

There is definitely a difference bouncing with guns set at 100 vs 1000. It think it all depends on the way you attack. High angle, distant, high speed v.s slow and close where deflection is very, very minimal. Don't concern yourself with horizontal convergence- the guns are too close together. The important factor is vertical convergence. 

 

Personally, I've played around with large adjustments to know that it does make a difference- for me. Is there a difference between 300m and 350m? Not enough to notice. Were talking 1-2 inches when put on paper. When you make changes go by hundreds instead of tens.

 

There is a difference between planes. If I use the settings for my SPAD in my SE5a, I can't hit crap. Likewise, the same settings don't work in german crates- for me. Going further, the settings between .303 vickers and 11mm vickers balloon guns aren't the same either. If I use the .303 settings for 11mm something seems off and I seem to miss a lot of my shots. 

 

For most folks 100m or 200m should do fine. The only way to sort it out is to continually attack a plane running the same route over and over and over and over and over and over and over until it feels right and your rounds coincide with your natural point of aim. Remember though, most of the time you aren't leading enough and setting your sights out far helps to compensate in this regard.

 

I'm sure someone will be along here shortly to tell me in completely wrong, whateverrrrr. This is all from dozens if not hundreds of hours spent attacking AI for gunnery practice on a personal server/QM. Its really down to what feels right for you.

 

Share this post


Link to post
Share on other sites

I use 250m. Bullet drop is only 3.5 feet at that distance assuming muzzle velocity of 750m/s.

Share this post


Link to post
Share on other sites
Posted (edited)

I use 400 and it keeps trajectory relatively flat out to that distance.  Makes it easy to pick off targets at longer range.

Edited by US63_SpadLivesMatter

Share this post


Link to post
Share on other sites
2 hours ago, US93_Talbot said:

It certainly changes vertically. It does in every other plane on the WW2 side so why would it not here? 

 

 

 

It does not look like it at all. Here are screenshots of 109F2 for comparison with the Camel.You can see that in the 109 case at 1000m the shots are pitched well up to the bottom of the upper vertical line. At 100m they go straight through the pipper.  In the case of the Camel there is no visible difference: simce the gunsight is also in exactly the same place, I cannot see how there is a vertical component.  If the screenshots are not clear enough, just start a mission in QMB on the runway and look at the trajectory compared to the pipper.

 

F2 1000m

1541651415_F21000m.thumb.jpg.ad69dfccad2f65e7941b3a216afd9d4e.jpg

 

F2 100m

286276236_F2100m.thumb.jpg.caa1c4685f5486bc421f21b9032834b9.jpg

 

Camel 1000m

1596430863_Camel1000m.thumb.jpg.a4e4dcf9a85890b9c7d1a11211732236.jpg

 

Camel 100m

1479312687_Camel100m.thumb.jpg.b243b5e4a3686449a47f200324c02888.jpg  

Share this post


Link to post
Share on other sites
3 hours ago, US93_Talbot said:

It certainly changes vertically. It does in every other plane on the WW2 side so why would it not here? 

 

Unfortunately you can only change the horizontal.  In the WW2 part of this forum is an ongoing discussion about the effectiveness of .50 ammunition.  For me, part of the problem in that debate is that we're offered six or eight guns producing a wafer of fire rather than the cone which was intended.

Share this post


Link to post
Share on other sites

300 seems to 'feel' good for me, but if changing convergence has a significant effect I haven't really noticed...

  • Thanks 1

Share this post


Link to post
Share on other sites
50 minutes ago, DD_Arthur said:

 

Unfortunately you can only change the horizontal.  In the WW2 part of this forum is an ongoing discussion about the effectiveness of .50 ammunition.  For me, part of the problem in that debate is that we're offered six or eight guns producing a wafer of fire rather than the cone which was intended.

 

That is incorrect for WW2 planes. Look at the screen shots of the 109 tracers. Or start a P-51 on the runway and fire to compare the sight picture at 100m and 1000m. It is very obvious that the convergence is both horizontal and vertical.   The problem with the 50 cals is that to get the sort of cone some people want, you need to be able to set the convergence of pairs of guns separately, which we cannot do.

  • Upvote 2

Share this post


Link to post
Share on other sites
Posted (edited)

Yeah there are screenshots showing the rounds arcing like they should.

 

In this super realistic game, why would they not do this? They go through the trouble of distinguishing between all these round types and the different damage, yet don't do something as basic as trajectory?

 

Edit to add:

 

The screen shot I have seen showed the arc while looking from 3rd person, out from the 7ish looking at the rounds as you fire. 

 

Whats the difference between what that 109 is firing vs .303 vickers? What round is it firing? Might be something heavy and slow making it a much different trajectory than a .303? 

Edited by US93_Talbot

Share this post


Link to post
Share on other sites
11 minutes ago, US93_Talbot said:

Yeah there are screenshots showing the rounds arcing like they should.

 

In this super realistic game, why would they not do this? They go through the trouble of distinguishing between all these round types and the different damage, yet don't do something as basic as trajectory?

 

Edit to add:

 

The screen shot I have seen showed the arc while looking from 3rd person, out from the 7ish looking at the rounds as you fire. 

 

Whats the difference between what that 109 is firing vs .303 vickers? What round is it firing? Might be something heavy and slow making it a much different trajectory than a .303? 

 

109 F2 uses 2 x 7.92mm machine gun "MG 17", 500 rounds, 1200 rounds per minute, synchronized. Rifle caliber round similar to Vickers .303, slightly higher MV.

Clearly in the F2 case the vertical convergence is modeled. I really do not see it in the Camel. The drop over 1000m is about 10m, so the pitch up of the bullets should be very obvious, as it is in the F2. It just is not there in the Camel. Use the Aldis and you can see more clearly - the trajectory is the same for 100m and 1000m.

 

If you have two screenshots that can be overlayed to see a difference between the 100m and 1000m setting, let's see them.  I have just done tests using an outside camera position - overlaying 100m and 1000m pictures I can see no difference between the tracer trajectories. 

 

The ballistics trajectory is modeled just fine AFAIK - the vertical convergence on the FC planes appears to be set at a fairly low range, and not player adjustable, that is all.  Which is fine, IMHO, since at WW1 ranges there would be only a small difference. 

 

 

 

 

Share this post


Link to post
Share on other sites

 

Erm, so you're saying the ladies like a pilot with a 300-400m convergence over, say, 250?  Look, when I said 200m, I was joking of course, it's actually 900. Uh-oh 950 now!

 

But as far as gunnery goes, the consensus seems to be that in-game convergence doesn't really make a difference and is more a "feel" thing or some kind of placebo.

 

So really, follow the tracers and git gud. Keep a steady hand and a steady ship.

 

 

Share this post


Link to post
Share on other sites
10 hours ago, unreasonable said:

That is incorrect for WW2 planes. Look at the screen shots of the 109 tracers. Or start a P-51 on the runway and fire to compare the sight picture at 100m and 1000m. It is very obvious that the convergence is both horizontal and vertical.   The problem with the 50 cals is that to get the sort of cone some people want, you need to be able to set the convergence of pairs of guns separately, which we cannot do.

 

That is why I've been thinking that the simplest solution (no big UI changes) would be to select a custom convergence (current system) or a historical convergence (hard-coded pre-set for the particular aircraft). It'd still take a lot of work - but it'd probably be easier to implement.

Share this post


Link to post
Share on other sites
13 hours ago, US63_SpadLivesMatter said:

I use 400 and it keeps trajectory relatively flat out to that distance.  Makes it easy to pick off targets at longer range.

 

So you're saying a longer convergence flattens the curve of the natural bullet drop?  I mean, if you put the sights on a kite 400m away flying directly in front of you at the same altitude and direction (so no deflection required), you'll hit it .... or do you also have to account for bullet drop by aiming a little higher? And someone with say a 200m setting would fall short under the same circumstances?

 

What I'm trying to understand is that what we may have in FC is just bullet drop with the vertical convergence settings making no difference at all. But I really don't know hence this thread.

 

I have done minimal tests on various settings which weren't conclusive either way. But that could easily be attributed to my poor flying/shooting at times. Some days you're just in the zone and sometimes you're not. Biorhythms or something.  

Share this post


Link to post
Share on other sites
Posted (edited)

What we do have in FC is bullet drop (ie a normal ballistics curve) but with a fixed vertical convergence, which looks fairly close to me, maybe 200m.  Up to about 250m, which is as far as you will usually fire in FC,  there is negligible divergence from a flat trajectory. Even at 350 the drop will only be ~18 inches below the LOS.

 

This calculator is quite useful  -  it makes nice graphs. ;)  You can take the .308 and adjust individual variables to match the Vickers.  Add in some wind speed.  The zero range is equivalent to the convergence range for us - set it to 100m and then 1000m and you can see that the difference in the trajectory is massive. You have to pitch the trajectory so that it's highest point is ~4m above the LOS to get the bullets zeroed at 1000m. 

 

 http://www.shooterscalculator.com/ballistic-trajectory-chart.php

 

Edited by unreasonable

Share this post


Link to post
Share on other sites
10 hours ago, ST_Catchov said:

 

So you're saying a longer convergence flattens the curve of the natural bullet drop?  I mean, if you put the sights on a kite 400m away flying directly in front of you at the same altitude and direction (so no deflection required), you'll hit it .... or do you also have to account for bullet drop by aiming a little higher? And someone with say a 200m setting would fall short under the same circumstances?

 

What I'm trying to understand is that what we may have in FC is just bullet drop with the vertical convergence settings making no difference at all. But I really don't know hence this thread.

 

I have done minimal tests on various settings which weren't conclusive either way. But that could easily be attributed to my poor flying/shooting at times. Some days you're just in the zone and sometimes you're not. Biorhythms or something.  

 

A longer convergence *can* flatten your trajectory out to the point it is set, but not if you set it too far.

 

I used a ballistics calculator set for 8mm Mauser when I decided on my convergence setting, to find a mostly flat setting.

 

I definitely feel the difference trying to hit distant targets if I try to use a close convergence.

  • Thanks 1
  • Upvote 1

Share this post


Link to post
Share on other sites

If you zero to 1000m the bullets will pass some 3+  meters above the LOS at 250 m.   Zero at 100m and they will be about 0.25m below. Depends exactly what you use in the calculator.

 

Take a look at this mission.  Camel Firing Test.zip

 

Camel on the runway, so make sure your throttle is at zero so you do not move. Use the Aldis so that you can see what you are doing.  Set convergence to 100m.  There is a balloon in your sights.  It is 250m away horizontally, and only 32m higher than the Camel so the vertical component does not change much here.  It bobs around slightly but settles down a bit - use the position of the roundel to determine when to fire. Observe fall of shot.  Restart with 1000m convergence.

 

When I did this I could see absolutely no difference in where the rounds fall - if vertical convergence is modeled it should be obvious.

Share this post


Link to post
Share on other sites
Posted (edited)

First, you need to keep in mind that your sights don't sit on the same level as your barrel. I presume that might make an impact visually on how high it may cross the line of sight. It certainly affects at what point the bullet path crosses the line of sight and it needs to be computed into your table to spit out a proper ballistic chart.

 

Second, the target range set up you have won't be accurate for this either because gravity isn't pulling "straight down" on your round like it is on the ballistic table. It changes the path of the bullet relative to the boreline and sight line and you actually need the angle of incline/decline to calculate the proper bullet path and holdovers and all that. 

 

I chased (and continually do) this beast awhile back in RoF. I had been chasing the idea of finding the perfect sight range setting that gave the longest and flattest trajectory with the least amount of bullet rise and drop (its 75m by the way). I took an actual ballistic calculating program (https://www.sierrabullets.com/products/other-products/software/) I had that I use for reloading ammunition and calculating appropriate holdovers for long range shooting. I input all the given ballistic data from RoF, guesstimated the sight height on a SPADXIII, and gathered all information avaliable on the Mark VII .303 round from the period-which matches the data given in RoF and FC. Not all rounds are created equal so I had create the entire simulated round from scratch and not a template offered in the software. The first time I ran it, it produced results that were all f'd up because I had metric and imperial measurements cross contamination. I ran out with my wrong data and was thoroughly smited. The next time I ran the numbers it produced results more in line with reality, seen here:

300m_1554515812.JPG

 

That shows the line of sight at the top, with the bore line about 6 to 8 inches below the sightline, with the "sight" set at 300m. The round is very flat and 8 inches of rise at 200 meters is imperceptible to our eye in game.

 

 

For a game test, I would suggest setting sights at 1000 and getting an AI to fly straight and level at 500m away from you. 500m will be the highest point in the arc (possibly) and the rounds might be high enough to go over the plane. I never mapped out 1000m in my calculator because RoF only went to 500m so I don't know what that bullet path looks like.

 

Thats how I'd test it.

Edited by US93_Talbot
  • Thanks 1
  • Upvote 1

Share this post


Link to post
Share on other sites
Posted (edited)

The difference between sight line and barrel line in a Camel is very slight - in fact if you aim down the iron sight on one of the guns it is only a couple of inches. You can plot it in the ShootersCalculator.com which is the one I used, adjusting the inputs for a Vickers.  Similarly, you can plot in the angle of fire relative to the horizontal into the calculator. For a 32 m height difference at 250 horizontal it is 7.29 degrees.  A stationary zeroing is actually better than a flight test if you want an accurate outcome as the trajectory will be affected by your airspeed while flying, as well as your altitude.

 

But none of this matters - I am interested in the difference in the fall of shot between the two convergence settings, not the absolute number for precise zeroing purposes. There should be a difference in the order of 109 + 4 inches at the 250m mark - 113 inches = 2.9 meters.  Whether that is +/- 1m actually does not matter, it should still be easy to see - as it is in the case of the F2 in the earlier screenshots.  Compared to the LOS the rounds at 1000m setting should still be well above the LOS at this range. They are not.

 

Setting up an in air test is not that easy, as you cannot fire guns while on autopilot but auto level uses your throttle input and the planes still yaw and pitch a bit as you adjust. Here is a quick go at it. P to start then check your throttle setting to get the sight level with the target using icons to see the range.  You will see all the rounds pass well under the target when you fire with it in the middle of the Aldis with 1000m convergence setting.

 

The vertical convergence setting does nothing - the guns look as though they are bore sighted.

Camel Firing Test 2 in Air.zip

Edited by unreasonable
  • Thanks 1

Share this post


Link to post
Share on other sites
Posted (edited)

Hmmm.....

 

Definitely shadiness going, I dunno.

 

Do the rounds look about 50ft low at 1000m? If so it would jive with the ballistic table I posted.

 

Maybe you have enough info there to bring up a bug ticket and get an official answer?

 

Make them tell us whether its modeled or not and the reasoning. We're the gun even able to adjust out that far due to mounting limitations in the plane? I don't know those specific answers but can possibly track down some training manual that might hold the key. 

 

Run the bug report route man.

 

Edit to add:

 

I wonder if in the porting or whatever, the guns kept the old RoF 500m convergence limit.....the rounds would certainly go under a plane at 1000m then.

 

 

Here is the overall trajectory of the MKVII .303 with no particular range setting: 

 

Overall+Traj+.303_1554514841.JPG

 

If it was just lined up to the boreline, rounds should pass around 10-15 feet low when aiming at a plane at 500m.

Edited by US93_Talbot

Share this post


Link to post
Share on other sites

In the flight test the target starts at 500m away - as you say this is about the highest point in the trajectory if set for 1000m convergence, so in the middle of the Aldis ring shots should either hit upper wing or miss high. They all miss low.   Seeing what is going on at 1000m is very hard as the tracers burn out before then IIRC.  I think the trajectories look fine - just that they are all the same irrespective of the convergence setting.

 

BTW the results are the same replacing the Camel with the SPAD in the balloon test, so it is not plane specific. I also tried using 250 and 500m to see if there was some glitch with numbers over 500. Again, I can see no difference.

 

I am not sure this is a bug - I suspect it is a design decision, and not an unreasonable one, since engagement distances were so short. Any deviations from LOS on a practical convergence setting would only be a matter of a couple of inches at up to 200m or so, probably less than the dispersion of the gun anyway. It is not like a Fw190 where a 500 - 1000m convergence would be a good setting for a head on attack against a heavy bomber.  But it does mean that if you are going to fire at targets 500m away you will have to aim high.

Share this post


Link to post
Share on other sites

20200721_235448.jpg

20200721_235509.jpg

Screenshot_20200721-233404_Samsung Internet.jpg

Screenshot_20200721-234323_Samsung Internet.jpg

Screenshot_20200721-234353_Samsung Internet.jpg

Screenshot_20200721-235118_Samsung Internet.jpg

Screenshot_20200721-235146_Samsung Internet.jpg

Bunch of stuff on how they aligned the sights. Nothing too crazy. Seems as if they chose 200 yards as a general starting zero and probably went in from there. 

 

 

  • Thanks 1

Share this post


Link to post
Share on other sites
Posted (edited)

Could the guns IRL even be physically elevated to zero at 1000m in these aircraft?

 

Seems like that might be beyond a simple sight adjustment in those days?

Edited by US63_SpadLivesMatter

Share this post


Link to post
Share on other sites
8 hours ago, US93_Talbot said:

What happens if you set your sights to 500m? Do they line up there?

 

No. I tried that in case there was some strangeness in the 500-1000 range. I can see no difference in the fall of shot whatever the convergence number.  Also tried with Camel and SPAD. 

Share this post


Link to post
Share on other sites

Well you've got me convinced for sure. So weird because it certainly feels different when you go from 200 to 1000.

 

I'll need to make some side by side video for comparison. 

 

Has to be fixed at 200m if its not adjustable. I would really like an official statement on it for sure. 

 

 

images.jpeg-7.jpg

Share this post


Link to post
Share on other sites

 

 

On 7/23/2020 at 11:32 AM, unreasonable said:

I can see no difference in the fall of shot whatever the convergence number

 

That's what I thought just with the naked eye in-game. Thanks for testing this out unreasonable.

 

On 7/23/2020 at 12:47 PM, US93_Talbot said:

I'll need to make some side by side video for comparison. 

 

Has to be fixed at 200m if its not adjustable. I would really like an official statement on it for sure. 

 

Are you working on the side by side comparison Talbot? Could be interesting .... or another spanner? As for an official statement, I'd like that but .... hmmm .... unlikely.

Share this post


Link to post
Share on other sites

Yeah had some PC issues the other day and had to nuke the site from orbit. 

 

Will get a side by side up hopefully in the next few days.

Share this post


Link to post
Share on other sites
Posted (edited)
4 hours ago, ST_Catchov said:

 

That's what I thought just with the naked eye in-game. Thanks for testing this out unreasonable.

 

Are you working on the side by side comparison Talbot? Could be interesting .... or another spanner? As for an official statement, I'd like that but .... hmmm .... unlikely.

 

Think nothing of it: with my failing reactions and eyesight, I enjoy this kind of interactive detective work as much as sim-flying these days.  Oddly enough when this topic started I had a vague memory of the developers saying something about convergence in FC being bore sighted, but I could not find it. I need an upgraded, younger  newer Alexa bird who can do more than say "I am sorry I cannot do that" when I ask it to perform a personal service. Like a search.

Edited by unreasonable
  • Thanks 1

Share this post


Link to post
Share on other sites
Posted (edited)

I just did some QMB's in a D7f against some various slow fliers, and with 400m convergence, firing at 400m (icons on to verify range), the shots were for the most part dead-on.

 

In fact the misses that did occur were a tad high.

 

So if convergence isn't actually working, the only explanation I can see for me personally is that there is some unconscious adjustment I am making as the target was slowly swaying back and forth.  At a couple points however, when the targets stabilised, the sight was right on the them, and these all turned out to be hits.  No low shots.

Edited by US63_SpadLivesMatter
  • Thanks 1

Share this post


Link to post
Share on other sites

I checked my balloon zeroing range mission with a Fokker with collimator sight - again no visible difference to trajectory, although the Fokker's guns do have a slightly flatter trajectory than the Camel's. 

Share this post


Link to post
Share on other sites

Made the comparison video. .303 and balloon guns diving on targets zero at 100m and 1000m.

 

It is rendering and I'll post it in a bit.

Share this post


Link to post
Share on other sites
On 7/24/2020 at 4:39 AM, unreasonable said:

I need an upgraded, younger  newer Alexa bird who can do more than say "I am sorry I cannot do that" when I ask it to perform a personal service. Like a search.

Won't be long and we'll all get a chip in the head to do all that for us. I can't wait so I can be as smart as you guys.

Share this post


Link to post
Share on other sites

 

Quote

 

I can't wait so I can be as smart as you guys.

 

 

Science and industry face the greatest challenge of the 21st century.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...