Getting optics magnification from the config in A3

[Rydygier 1317]

I found this thread which gave me some light, not all is clear in A3 though. Basing on the formula:

magnification = X/zoom(Min)

I got 0.75 for SOS (75 = X/0.01) and DMS (12 = X/0.0625) but 1.1 for ARCO (10 = X/0.11) and yet another value for MRCO. So, what determines X?

[ceeeb 147]

Magnification is a ratio, all you need to do is divide a "baseline" config FOV value by the config FOV of the scope. Generally the baseline should be a default view (without using zoom temporary).

There a two problems:

- Arma 3 historically uses different baseline FOV values for soldiers on foot and soldiers in vehicles. Your eyes get better the instant you get into a vehicle (see bug tracker issue 0009173: Inconsistent zoom/FOV between naked eye and vehicles/weapons without optics).

- Some optics and scopes are not configured correctly to match the expected magnification (as stated by GUI).

Example:

Human portable optics, which get compared to default soldier units initFOV = 0.75

Scope: RCO

Advertised magnification: 10x

Config FOV: 0.11

Actual magnification in game = 0.75/0.11 = 6.81818x

Scope: DMS

Advertised magnification: 1x - 12x

Config FOV 1: 0.125

Config FOV 2: 0.0625

Actual magnification 1 = 0.75/0.125 = 6x

Actual magnification 2 = 0.75/0.0625 = 12x

Scope: Laser Designator

Advertised magnification: 6x - 60x (shown on screen)

Config FOV Min magnification: 0.1242

Config FOV Max magnification: 0.0125

Actual magnification Min magnification = 0.75/0.1242 = 6.03865x

Actual magnification Max magnification = 0.75/0.0125 = 60x

Now a vehicle scope, compared to default unit in vehicle which have initFOV = 0.7 (EDIT: this may not be as true in 1.36 as it used to be):

Optics: SDV gunner periscope

Advertised magnification: 5x - 40x (shown on screen)

Config FOV Min magnification: 0.14

Config FOV Max magnification: 0.0175

Actual magnification Min magnification = 0.7/0.14 = 5x

Actual magnification Max magnification = 0.7/0.0175 = 40x

And just to mess things up even more, I just noticed the Sochor gunner and motar gunner HUD magnification is relative to a initFOV = 0.75 (in the past these optics were compared to 0.7)

Edited December 17, 2014 by ceeeb

[Rydygier 1317]

Thanks for that explanation. Interesting. So seems, for some infantry optics displayed zoom doesn't match "real" zoom, like for RCO, good to know. For me 0.75 seems suitable answer though, as in fact I do not need necessarily match calculated zoom with displayed number, I need that info for the function, that tries as fully as possible, based on the config, dynamically evaluate various stuff, including optics, for the purposes of selling system. If for all infantry optics we have same constant (0.75), then formula using it and zoom config values will return proper, proportional to real zoom "price" values. OK for me.

[scifer 10]

As stated at http://forums.bistudio.com/showthread.php?82952-How-to-get-correct-magnification

Some optics have different base numbers like the CUP_optic_ACOG

displayName = "Trijicon ACOG TA31F";

Advertised magnification: 1.5x - 6x

opticsZoomInit = 0.0623;

opticsZoomMax = 0.0623;

opticsZoomMin = 0.0623;

Actual magnification = 0.2492 / 0.0623 = 4

How to find the base number from config then?

[ceeeb 147]

I'm not sure about that scope, but from the class name I assume it is part of the Community Upgrade Project.

Assuming CUP has not changed the soldier FOVs, then that scope magnification relative to normal soldier view would be 0.75/0.0623 = 12.04x

For a total conversion mod, the could have adopted the zoomed in view (config = 0.375) as a baseline of 1x (which is reasonable, as it is much closer to real world human eye acuity than the default view), which makes the ACOG magnification 6x.

The key thing is all scopes in the game should be using the same method to create the configs from. Chances are not many community made mods use the same technique as BIS, let alone each other.