Gun sight image size analysis

[715]

Saxman I don't think your calculation is correct but I will double check it.

A mil is a mil (well, except for the slight error of "metric" mils) and geometry is geometry: 30 ft at a range of 200 yds subtends 50 mils.  (It's actually 199.8 yds using real angles.)

[Baumer]

Baumer doesn't the adjustment on the reflector sight change the ring size for the mil setting and range set by the pilot? So 70 mils might be the standard training sight but all aircraft wouldn't have a 70 mil ring all the time. I understand the advantage of having a consistent size but that still won't give you more realism except when your target is the correct size at the correct distance.

FLS that gets into the specifics of each sight model some could be adjusted while others could not.

The standard for the N-9 sight was the inner ring is 35 Mil and the outer ring is 70 Mil

[Baumer]

Saxman do the following calculation and insert the resolution of your screen to get the proper pixel size.

360 / 6400 = 0.05625, so 1 Mil is 0.05625 degrees

0.05625 x 100 = 5.625, so 100 Mils is 5.625 degrees
0.05625 x 50 = 2.8125, so 50 Mils is 2.8125 degrees
0.05625 x 25 = 1.40625, so 25 Mils is 1.40625 degrees

Now check your field of view setting in Aces High. For My system the FoV is 100 degrees and my horizontal resolution is 1680.

1680 / 100 = 16.8, so 1 degree FoV = 16.8 pixels

Now;

1.40625 x 16.8 = 23.625, so 25 Mil is 23.625 pixels on my system
2.8125 x 16.8 = 47.25, so 50 Mil is 47.25 pixels on my system
5.625 x 16.8 = 94.5, so 100 Mil is 94.5 pixels on my system

That is how large the math says the image should be.

[Saxman]

1920px horizontal, at 100 FoV
1920 / 100 = 19.2
100 Mil = 108 pixels on my system.

In the adjusted sight shot, which was done from default head position on my system:



JUST the 100mil circle (excluding the extended cross) comes to about 95px. Allowing a +/- margin for error, AND errors in my mocked-up gunsight, I would say that more or less confirms my calculations based on target wingspan. For the full-cross Mk.8 sight to scale properly, the size of the gunsight in the bubble top Corsairs needs to be doubled (The -1 Birdcage is more troublesome, however while I see the Mk.8 referenced for the 1A/C/D and 4 I don't for the -1, so she MAY have used another sight).

[hitech]

Now I understand the issue Baumer, thanks.

HiTech

[Saxman]

Now I understand the issue Baumer, thanks.

HiTech

*Hopes this means the Corsair gunsight modeling gets fixed.*

Sorry to push, I've just been wishing for that since the Hogs got remodeled. It's one of my top Corsair wishes, right up there with a lightened land-based 1A option.

[Saxman]

1920px horizontal, at 100 FoV
1920 / 100 = 19.2
100 Mil = 108 pixels on my system.

In the adjusted sight shot, which was done from default head position on my system:

(Image removed from quote.)

JUST the 100mil circle (excluding the extended cross) comes to about 95px. Allowing a +/- margin for error, AND errors in my mocked-up gunsight, I would say that more or less confirms my calculations based on target wingspan. For the full-cross Mk.8 sight to scale properly, the size of the gunsight in the bubble top Corsairs needs to be doubled (The -1 Birdcage is more troublesome, however while I see the Mk.8 referenced for the 1A/C/D and 4 I don't for the -1, so she MAY have used another sight).

Actually, I might want to retake that screenshot as I MAY have had a smaller monitor when I did my original calculations. At one point I was using a 1600x1200 monitor, I can't remember if I upgraded to my current 1920 when I did these tests. If I still had the 1600 when I took the screenshot I posted, my adjusted sight would actually be nearly EXACT based on your own calculations (94x94 for the outer ring. Larger total if you include the extended cross).

Edited:

Ok, here's a new screenshot with the adjusted sight based on the calculations on how large the sight should be:



The 100mil ring is 108x108, based on the formula you provided, resulting in the total size of the sight being 159x159. In order for the Mk.8 gunsight to be properly sized in the F4Us on a 1920x1200 monitor, the gunsight would need to be a total size of 159x159 pixels.

However I DO wonder whether it's the horizontal or vertical resolution that's most important, as I believe there's points where the vertical height of the FoV stays the same, while the horizontal resolution increases. This COULD throw off the size calculations.

[FLS]

Saxman I'm pretty sure the FOV has to change symmetrically.

[Baumer]

One thing that still surprises my is how accurately HTC models the cockpits (I know I shouldn't be but when I stumble on a new way to verify it, I just smile)

Saxman, I doubt the sight for the Corsair should be the full 159 by 159 but I see what you're getting at. I suspect the image should be the same size as the projecting lens from the sight. Also the issue with the Mk8 100 mil sight seems to apply to all the USN aircraft not just the Corsair.

Here's the Corsair with your sight and where I suspect the image should stop.


Here's the Hellcat where I scaled up my Mk8 to the proper size


And the FM2, even on the early 3D models the sight lens is still the right size.


I know this is a minor issue and I appreciate you looking at it Hitech.

<S> Baumer

[BulletVI]

boumer

          A good and fair point on the gun-sights. I too now having read your post on them have found out what you are meaning.
But may i point out that in reality a pilot upon receivership of the aircraft he is to fly in-to combat would first have flown down to the gunnery range then had the aircraft raised at the back to imitate level flight. Then he would have sat in the cockpit and fired of a burst or two at a static target. then after that he would have manually adjusted the gun-sight up or down or diagonally. As well as setting his convergence on his bullets to a certain distance. Note that the pilot would have set his gun-sight to fit his position in the cockpit i.e the way he would slouch slightly to see the sight and the way he may have skwinted his eye's when firing. Note the sight was adjusted to his personal preference.

Now we in Ace's Only have the ability to set convergence in the game. But other games like iL2 you can also set your gun-sight up you can raise and lower move it side to side to fit the position you sit within the aircraft. And you can also increase the size of the gun-sight for your seating position
within the aircraft.

Do you think that if HiTech could implement in to the game that inside the main hangar we could also set the gun-sight to match our preferred seating position as we set our gun convergence. That it may help combat this . ????

As i said pilots did it for real in WW2
Maybe it should be tried and tested and if it help's then we should stick with it.

It's just me putting in my 2cents worth you may ignore me if you all wish.          

BulletVI

[Baumer]

BulletVI

I think I understand what you're asking for, but I doubt HTC would implement it. The flexibility you are talking about was not available on all aircraft, for example in the US Navy planes the sight was not adjustable in any direction. Also, in the Corsair and Hellcat the seat has no forward or back travel. The only adjustment was to move the rudder pedals, not the seat. So if HTC was to implement what you're asking for, it would depend very much on what was historically possible for each particular aircraft.

But if HTC likes you idea maybe they will implement it, who knows?
 

[BulletVI]

BulletVI

I think I understand what you're asking for, but I doubt HTC would implement it. The flexibility you are talking about was not available on all aircraft, for example in the US Navy planes the sight was not adjustable in any direction. Also, in the Corsair and Hellcat the seat has no forward or back travel. The only adjustment was to move the rudder pedals, not the seat. So if HTC was to implement what you're asking for, it would depend very much on what was historically possible for each particular aircraft.

But if HTC likes you idea maybe they will implement it, who knows?
 

Ah i wasn't sure of the American aircraft but i know for certain that British aircraft the sight on most like the Spitfire was adjustable to the Pilot.
But even for the American Aircraft they could do it as an easy way for some people to understand on setting up the gun-sight. I understand it may not be historicaly accurate but for a computer game you can get away with it as it can be an easy fix for a simple to a no brainer problem.   

[Saxman]

Saxman, I doubt the sight for the Corsair should be the full 159 by 159 but I see what you're getting at. I suspect the image should be the same size as the projecting lens from the sight. Also the issue with the Mk8 100 mil sight seems to apply to all the USN aircraft not just the Corsair.

I think the size of the sight relative to the projector is a result of the known perspective issues within the game's engine, with objects further away appearing much smaller than they should. This is most clear in your images of the F6F and FM-2: the gunsight image shouldn't be cut off the way it is here.

The Corsair sight DOES also project somewhat differently, too. It's not projecting onto a small piece of glass attached directly to the sight, but that large glass plate well above it. It's feasible that the image could get enlarged in a manner similar to an overhead projector.

[Baumer]

But what about the axis gun sights?

Well after digging through more of my files I've found information on the Revi 16B sight for the 190A-8 so I will be checking that as well.

[AKDogg]

Most gunsight reticules showed larger the the reflector glass.  Here is what I mean as a example:

Type 98 gunsight:  http://www.youtube.com/watch?v=NXsVg8F91t8

Mk. VIII gunsight:  http://www.youtube.com/watch?v=G7KvpWloagE&feature=related

RAF TypeI Mk,II gunsight:  http://www.youtube.com/watch?v=Blem3FlkaMc&feature=related