When people think of converting their sensitivity between games with a different field of view, the most common strategy is to simply maintain the same cm/360. Surely 30cm/360 on 110 FOV is the same as 30cm/360 on 103 FOV? While it may take the same amount of mouse movement to perform a 360, the way your aim feels will change. The larger the difference in FOV, the larger change in how your aim feels between games.
Take the extreme example of maintaining the same FOV from hipfire to a 10x sniper scope. Same cm/360, but the scope becomes impossibly fast to control. In comparison, focal length scaling has a drastically lower cm/360 but it feels the same as the hipfire.
Focal Length Scaling AKA 0% Monitor Match
We’ll save the technical explanations for another blog and simply focus on how it works and why it’s good. With focal length scaling, all fields of view will feel the same at the crosshair. Imagine these two scenarios. In one you are standing 100 meters away from a target. In the other you are standing twice as far away at 200 meters but you zoom in with a 2x scope. If the enemy in both scenarios moves the same amount, it would take the exact same amount of real life mouse movement to track that target in both hipfire and 2x scope.
With other conversion methods like cm/360 or 100% monitor match, the scoped aim in that example would be more sensitive and require less mouse movement even though the distance to the target on the screen is effectively the same.
To perform this calculation we need a few things first and don’t stress out if you don’t know the values as we will cover how to find them below.
- FOV value of both games eg. 90 & 103
- FOV scale of both games eg. Horizontal 4:3 & Horizontal 16:9
- Sensitivity value of game 1 eg. 2
- Yaw value of both games eg. 0.022 & 0.0066
- Sensitivity of game 1 converted to sensitivity scale of game 2 eg. 2 > 6.6666
How to Use Focal Length Scaling Between Games
There are paid calculators such as mouse-sensitivity.com, but if you are looking for a free option we have devised a free method you can use instead.
First things first, you need to know the field of view value and field of view scale you are coming from and going to. You can often do this through some googling with terms such as “X Game FOV calculator”, “X Game sensitivity calculator”, “How is X Game field of view measured?” etc. If you are really stumped and can’t find what your FOV is or how it is measured, check out our video on how to find the FOV of any game below.
It is essential that we convert the field of view from game 1 to the scale of game 2 if they measure field of view differently. Most popular games will use either Vertical Degrees, Horizontal 16:9 or Horizontal 4:3 for their scale. You can use the calculator in the video above to convert between the three.
It isn’t the most elegant solution, but you can open the calculator and find the AngleVP section on the left, as shown in the image below.
There are three outputs for fields of view on the left, the top most output is Vertical Degrees, the middle is Horizontal 4:3 and the bottom is Horizontal 16:9. For example, if we were converting from CS:GO it is known that the FOV is Horizontal 4:3 and 90 so we move that slider shown above until the output in the Horizontal 4:3 section is close to 90. You will then need to click on the ‘AngleVP’ field and manually adjust the number to get as close to 90 as possible.
If we were trying to focal length scale our sensitivity into Overwatch which is a Horizontal 16:9 game, we now have our CS:GO FOV converted from Horizontal 4:3 to Horizontal 16:9 with 106.2684 as you can see in the image above.
If one of your games happens to use a unique FOV scale you will need to follow the steps in the video above to match up your fields of view in the game you are converting to.
Once you have the fields of view, we now need to find the ‘Yaw’ value of the games. This is essentially how the game determines its in-game mouse sensitivity values. To do this, download KovaaK’s Sensitivity Matcher. In the dropdown box at the top, click on your game if it is listed. Some games will share a yaw, such as the ‘Quake/Source’ option which is applicable to games like CS:GO, Apex Legends and Quake Champions. If you can’t find what sensitivity scale or yaw value your games are using the Sensitivity Matcher can find that for you. For instructions on how to use the tool, you can read and watch the material in the link above, and/or hit ‘Advanced Info’ when in the Sensitivity Matcher to see the correct steps and up to date keybinds.
Find your perfect 360 degree spin then enter your in-game sensitivity into the ‘Yaw’ field, hit the dropdown at the top and click on ‘Swap sens & yaw’. This will now show you the ‘Yaw’ value for you game in the ‘Yaw’ field. A quick video demonstrating this is shown below.
With these yaw and sensitivity values we do the following (Game 1 sens * Game 1 yaw = Game 2 sens * Game 2 yaw). This will put the sens from game 1 (the game we’re coming from) into the same format as game 2 (the game we’re converting to).
2 * 0.022 = X * 0.0066
X = 2 * 0.022 / 0.0066
X = 6.6666
Now we have our game 1 sensitivity in the scale of game 2 we can finally do the focal length scaling calculation
(FOV game 2/ 2)/tan(FOV game 1/ 2) * Game 1 sens (that has been converted to game 2 scale)
For the example we’ve been working through it will look exactly like the image below.
Head to a calculator like Desmos and type in exactly what you see above. You would change ‘103’ with the FOV of the game you are converting to, aka ‘game 2’. 106.26 with the FOV of the game you are coming from (make sure they are the same FOV scale or it won’t work). Lastly you would change 6.6666 with the sensitivity of game 1 that was converted to game 2 scale with ‘X = Game 1 sens * Game 1 yaw / Game 2 yaw’. The output is the sensitivity you would enter into game 2.
That’s it! The process is daunting and inconvenient which is why this is usually hidden behind paid tools. If you have the patience to learn the process you can make these calculations relatively quickly, especially if the FOV and yaw values of your games are common knowledge.
If anything wasn’t clear or you are stuck on a particular step, please don’t hesitate to reach out to Struth on our Discord.
