ENBSeries
If your videocard is suitable you may want to give enbseries a try.
ENBSeries is basically a tweak for DirectX. This is how it works: A 3D game talks to DirectX and DirectX talks to your videocard to create your 3D scene. There are many settings in DirectX to play around with. However, since there are also many hardware configurations possible game designers provide the most default settings and tools to tweak some of these settings, so they work for most/all videocards. ENBseries is basically an INI file that overrides default/vendor settings and gives you access to very specific settings.
You'll probably have to spend some time to fine tune enbseries.ini to your 3D hardware and game configuration but it's worth it. Promise.
GTA4 with ENBSeries graphics
Install
Download ENBSeries (ENBSeries V0.076.zip)
and put enbseries.ini and the d3dx9 DLL files in your game directory (where your game .exe executable is, not the Windows folder). When in game, hit shift-F12 to enable/disable it. That's it! Adjust settings in your enbseries.ini with notepad.
Here is my personal tweaked enbseries.ini for ARMA2 Free with some notes. Just copy and paste it into your enbseries.ini file, replacing the existing code. Or start a new file yourself.
enbseries.ini
// ENBSERIES settings ARMA2 Free
// Press shift-F12 in game to enable/disable
// More info to get started way below under the settings
// -----------------------------------------------------
//
//// developer settings
[PROXY]
EnableProxyLibrary=0
InitProxyFunctions=0
ProxyLibrary=
//
//// use enbseries at start Y/N, additional settings
[GLOBAL]
UseEffect=1
AlternativeDepth=1
AllowAntialias=0
BugFixMode=0
SkipShaderOptimization=0
QuadVertexBuffer=0
EnableShaders_3_0=1
UseMRTRendering=0
AdditionalConfigFile=enbseries2.ini
//
//// Which effects should be tweaked
[EFFECT]
EnableBloom=1
EnableOcclusion=0
EnableReflection=0
EnableMotionBlur=0
EnableWater=1
EnableShadow=1
DepthBias=0
EnableDepthOfField=0
//
//// Keyboard shortcut codes. 123 = shift-f12
[INPUT]
KeyUseEffect=123
KeyBloom=120
KeyOcclusion=121
KeyReflection=122
KeyCombination=16
KeyScreenshot=44
KeyShadow=119
KeyWater=118
KeyShowFPS=106
//
//// Reflection
[REFLECTION]
ReflectionPower=60
ChromePower=60
UseCurrentFrameReflection=1
ReflectionQuality=1
ReflectionSourceSpecular=50
ReflectionSourceTFactor=50
UseAdditiveReflection=1
ReflectionDepthBias=0
UseLowResReflection=1
ReflectionSinglePass=1
UseEnvBump=1
EnvBumpAmount=100
EnvBumpOffset=100
ReflectionFlip=0
//
//// Light bloom
[BLOOM]
BloomPowerDay=7
BloomFadeTime=400
BloomConstantDay=1
BloomQuality=0
BloomScreenLevelDay=30
BloomCurveDay=0
BloomPowerNight=1
BloomConstantNight=1
BloomCurveNight=0
BloomScreenLevelNight=10
BloomAdaptationScreenLevel=24
BloomAdaptationMultiplier=100
BloomAllowOversaturation=1
BloomMaxLimit=100
//
//// Screen Space Ambient Occlusion
[SSAO]
UseFilter=1
OcclusionQuality=2
FilterQuality=1
DarkeningLevel=20
BrighteningLevel=20
IlluminationLevel=20
AdditiveIlluminationLevel=25
UseAmbientOcclusion=1
UseIndirectLighting=1
FadeDistance=50
UseForAlphaTest=1
UseForAlphaBlend=1
//
// Color corrections, saturation, screen, gamma
[COLORCORRECTION]
DarkeningAmountDay=15
ScreenLevelDay=50
GammaCurveDay=1
ColorSaturationDay=1
DarkeningAmountNight=15
ScreenLevelNight=25
GammaCurveNight=1
ColorSaturationNight=0
UsePaletteTexture=0
//
// Water
[WATER]
UseWaterDeep=0
WaterDeepness=20
WaterQuality=0
//
// Shadows
[SHADOW]
ShadowFadeStart=40
ShadowFadeEnd=80
ShadowAmountDay=50
ShadowAmountNight=40
ShadowScreenLevelDay=40
ShadowScreenLevelNight=30
ShadowQuality=1
UseShadowFilter=0
FilterQuality=2
ShadowBlurRange=30
//
// Filter, monitor. Make sure the refresh rate matches your monitor.
[ENGINE]
ForceAnisotropicFiltering=0
MaxAnisotropy=8
ForceDisplayRefreshRate=0
DisplayRefreshRateHz=60
//
// Motion blur (may impact frame rate)
[MOTIONBLUR]
MotionBlurQuality=1
MotionBlurVelocity=0
MotionBlurRotation=0
//
// Specular settings pixels
[PERPIXELLIGHTING]
SpecularColorMin=0
SpecularColorMax=100
SpecularColorMultiplier=100
SpecularGlossinessMin=0
SpecularGlossinessMax=100
SpecularGlossinessMultiplier=100
//
// Depth of field
[DEPTHOFFIELD]
DOFQuality=2
DOFNumberOfPasses=1
DOFFocusRange=50
DOFBlurinessRange=10
//
// -----------------------------------------------------
// Important: Tweak this file to your own preferences
// It is not likely you have exactly the same system so you may see trash if
// you just use this
//
// You don't need to restart Arma2 every time while testing
// start editor, make a simple mission
// preview, abort, change this file, save, preview mission, and so on
// tweak for both day and night
// leave things you don't understand alone
// tweaking brightness and bloom may be enough
//
// You need this file in your program files/bohemia/Arma2free directory
// you also need d3d9.dll, d3dx9_26.dll and d3dx9_40.dll, these go into the
// same directory
// Get your files here: http://enbdev.com/download.htm
//
// You can also use this for other games. Just copy the ini and dll files to
// the root directory of your other game and tweak
//
// Note that not every videocard is suitable or supported
//
// important: make sure the refresh rate setting here matches your monitor
//
// Don't fix things that ain't broken. If you're fine with how everything
// is? Don't bother enbseries.
//
// Complete uninstall: just remove the enbseries.ini its dx9 dll files from your game directory
