Windows / Desktop Calculation not matching up

[heybg2]

I measured several distances in game with my settings, 650 dpi and 0.06 in-game sens in Fortnite and the calculator says it should be somewhere between 600 and 700 dpi depending on the % monitor match. However, after testing and measuring my physical mouse movement several times, it seemed to match up much more accurately with 550 dpi in window / desktop. I then tested my mouse in the DPI analyzer and I consistently got 0%-2.5% deviation only. Is there any explanation for why this may be happening?

[potato psoas]

Since DPI can only be set to intervals of 50, it has to round up or down. I replicated your settings but set the WPS to 1/11 and recalculated for 0% monitor match and the actual DPI is more like 578.125. 578.125 rounded up since it is closer to 600 than 550.

You get into problems like this when you convert from games to desktop instead of converting from desktop to games.

[heybg2]

Thanks for the response! So since Windows rounds to the nearest 50 DPI, is it even possible to have a DPI deviation of less than 50 DPI? Since windows would just round it up. I'm reference deviation as in the one that you calculate with the DPI analyzer.

[Drimzi]

44 minutes ago, heybg2 said:

Thanks for the response! So since Windows rounds to the nearest 50 DPI, is it even possible to have a DPI deviation of less than 50 DPI? Since windows would just round it up. I'm reference deviation as in the one that you calculate with the DPI analyzer.

Windows does not round anything. You can only set your mouse CPI in steps that are supported, and most mice have increments of 50, 80, 100, or are limited to 400, 800, 1600, 3200 CPI. The CPI is always different than what is configured. The error here is probably human error with the measurement, and not understanding how it works. All of those DPI results are correct, it just matters what point you are measuring to. If you do 100%, then it's going to be accurate to the pixel at the very edge of your display, and no where else. If you do 0%, then it's not going to be correct anywhere, but instead begin to slowly increase in discrepancy the longer you move your mouse.

[heybg2]

54 minutes ago, Drimzi said:

Windows does not round anything. You can only set your mouse CPI in steps that are supported, and most mice have increments of 50, 80, 100, or are limited to 400, 800, 1600, 3200 CPI. The CPI is always different than what is configured. The error here is probably human error with the measurement, and not understanding how it works. All of those DPI results are correct, it just matters what point you are measuring to. If you do 100%, then it's going to be accurate to the pixel at the very edge of your display, and no where else. If you do 0%, then it's not going to be correct anywhere, but instead begin to slowly increase in discrepancy the longer you move your mouse.

It still seems off though. According to the calculator 100% MM would be 700 DPI in windows, however when I measure it that is off by about an inch. Basically I'm going into a game and measuring the distance I have to move my mouse so the crosshair goes to the pixel that was originally on the edge of my screen. I then paused the game so it puts the cursor exactly in the center of my screen and then measure the distance it takes to move the cursor to the edge of the screen. When I did this the closest windows DPI that matched the in game movement I had with my original settings was 550 DPI. It almost exactly matched up every time and 700 was off by about an inch. I keep getting consistent measurements, so I don't think it is up to human error as far as the measurements go. Okay I just measured it several times again and tried to be as precise as possible. I got 1.78 Inches to move the crosshair to the edge of the screen and 1.41 Inches when moving the cursor to the edge of the screen from the center with 650 DPI for both. When I switched my DPI to 700 I got 1.25 Inches to the edge of the screen from the center. Finally, with 550 DPI I get 1.75 Inches to the edge of the screen. Just to be clear I'm measuring the distance to move the cursor horizontally from the center of the screen to the edge of the screen.

Edited May 10, 2018 by heybg2

[heybg2]

1 hour ago, Drimzi said:

Windows does not round anything. You can only set your mouse CPI in steps that are supported, and most mice have increments of 50, 80, 100, or are limited to 400, 800, 1600, 3200 CPI. The CPI is always different than what is configured. The error here is probably human error with the measurement, and not understanding how it works. All of those DPI results are correct, it just matters what point you are measuring to. If you do 100%, then it's going to be accurate to the pixel at the very edge of your display, and no where else. If you do 0%, then it's not going to be correct anywhere, but instead begin to slowly increase in discrepancy the longer you move your mouse.

I figured it out!! I had windows desktop scaling on 125%. I thought this only increased Icon and font size, but it actually scales every aspect of windows apparently lol. Once I changed it to 100% the measurements from the calculator were spot on! 

[Drimzi]

Oh, really? Good to know.

Yeah, 100% would be a match only if you are measuring to the edge of the screen. If you moved half the distance, then 50% would be a match. Just remember that the edge of the screen is arbitrary, as is any other point. You will end up with a different sensitivity if you changed the aspect ratio. In Windows, everything pretty much stays a static size, with the only thing changing being the location of the startmenu, tray icons, and your minimise/maximise/close buttons (Windows scaling is shit, and a lot of programs don't scale at all). Your cursor speed doesn't change at all. You can test this by disabling fullscreen display scaling and then changing your resolution, and then moving the cursor around. In games that don't have shit scaling (any game not using resolution based horizontal), the 1:1 fov doesn't change, and so the actual projection of the gameworld is identical even when changing aspect ratios, you just see more or less of it.

[heybg2]

Yea it's crazy how long I went fiddling around with measurements just to realize the scaling settings was affecting it lol. That makes sense though since all of the measurements for in-game for all my games matched up perfectly, but not for my desktop. Thanks for all the info though! If you didn't correct me, I probably would have just assumed the calculator wasn't working for me. 

[Drimzi]

@DPI Wizard Windows Scaling could be another special option to add when using Windows / Desktop.

[DPI Wizard]

4 hours ago, Drimzi said:

@DPI Wizard Windows Scaling could be another special option to add when using Windows / Desktop.

Definitely! I'll add it in the next update.