"Create a camera system which adds Arma 3 camera movement and zoom to ROBLOX."

-- local script 
local camera = game.Workspace.CurrentCamera
local player = game.Players.LocalPlayer
local mouse = player:GetMouse()

local isArma3Camera = false
local zoomLevel = 1

local function toggleArma3Camera()
    isArma3Camera = not isArma3Camera
    if isArma3Camera then
        camera.CameraType = Enum.CameraType.Scriptable
        camera.FieldOfView = 70
    else
        camera.CameraType = Enum.CameraType.Custom
        camera.FieldOfView = 70
    end
end

local function updateArma3Camera()
    if isArma3Camera then
        local mouseDelta = mouse.delta
        local rotationX = mouseDelta.x / 100
        local rotationY = mouseDelta.y / 100
        
        camera.CFrame = camera.CFrame * CFrame.Angles(0, rotationX, 0)
        camera.CFrame = camera.CFrame * CFrame.Angles(rotationY, 0, 0)
    end
end

local function zoomIn()
    if zoomLevel < 3 then
        zoomLevel = zoomLevel + 1
        camera.FieldOfView = camera.FieldOfView - 10
    end
end

local function zoomOut()
    if zoomLevel > 1 then
        zoomLevel = zoomLevel - 1
        camera.FieldOfView = camera.FieldOfView + 10
    end
end

mouse.Button2Down:Connect(toggleArma3Camera)
mouse.WheelForward:Connect(zoomIn)
mouse.WheelBackward:Connect(zoomOut)
game:GetService("RunService").RenderStepped:Connect(updateArma3Camera)