
  Why are mouse sensors in the middle of the mouse? - nickb
http://jonathanhedley.com/articles/2008/04/mouse-sensors
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dkokelley
"But moving just the forefinger — not the whole hand, or bunching all the
fingers, but just the forefinger — actually makes the mouse rotate,
particularly for left- and rightward movements. If the sensor is up the front
of the mouse, that rotation of the mouse will give the user the desired
outcome: the cursor will accurately move to the left or right, or back and
forth. But if the sensor is in the middle of the mouse, then all of that fine
control is lost: no or little movement will be registered."

Paraphrased: With the ball/sensor at the top of the mouse, you can have more
horizontal control by rotating the mouse left or right.

My response: With the way that the hand rotates (the base of the hand as a
fixed point), the speed of the cursor slows down the farther back the sensor
is placed. So in essence, you can get more precise horizontal control with our
current sensor placement standard than with a index-thumb sensor.

This is good because it's easier for the human arm to move the mouse quickly
horizontally by rotating at the elbow than it is to move vertically (by
rotating the shoulder, or in my case, moving my wrist/fingers).

Then again, I have my mouse set pretty sensitively, so I can traverse the
entire screen within the range motion my wrist allows (no need to lift my hand
at all). Also, I'm pretty sure that the difference is negligible compared to
sensitivity settings and advances in technology (such as slowing the cursor
when the mouse is moved slower... that sounds obvious, how about decreasing
the absolute speed of the cursor when the mouse is moved slower).

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danielrhodes
My first thought was that putting the sensor/ball in the middle means the
mouse is less sensitive to the way in which you hold it. That would mean that
if you hold the mouse at a slight angle, it would still behave the same as if
you hold it straight on. If you put the sensor in the front, the mouse becomes
more sensitive to its orientation, but it limits the different ways in which
you can hold the mouse since you must hold it straight on for it to behave the
same.

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jsmcgd
It only becomes sensitive to its orientation during the process of changing
the angle of the mouse and only then if you rotate the mouse about the dead
center. For yourself I'd imagine that you only really re-orientate the mouse
once per use. Also I'd imagine that you'd quickly start rotating the mouse
about the position of the sensor if it was a problem.

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cstejerean
Anyone still using their wrist, elbow or should to move the mouse is asking
for repetitive stress injuries. I highly recommend you try a trackball. Using
your fingers to move the cursor is a lot more convenient, the mouse itself
stays in the exact same place relative to the keyboard making it easier to
switch between them, and takes up less room on your workspace, as it doesn't
need room to move around.

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seer
well, I think that nowadays the optical sensors are quite sensitive, and it's
not that hard to achieve any apparent placement of the sensor through some
software modification of the output. So even if you place your mouse at the
far back, you can make it behave as though it's in front. Or at least I think
so...

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seer
well, I think that nowadays the optical sensors are quite sensitive, and it's
not that hard to achieve any apparent placement of the sensor through some
software modification of the output. So even if you place your mouse at the
far back, you can make it behave as though it's in front. Or at least I think
so...

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mlinsey
I don't see how. I presume mice only register changes in position, and not
changes in orientation. That's all you can measure with a ball so I presume
that's all that is measured with optical mice. So if you were for instance to
hold the top of the mouse in place and rotate the rest of the mouse around
that point, you would definitely register a change in position with the
optical sensor, and I don't know how you would do this in software. So the
mouse won't ever behave exactly like it would if the sensor were at the front.

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sanj
I think that your assumption is incorrect. The optical sensors are comparing
images, currently looking for translation. There's not reason they couldn't
look for rotation.

However, it is a firmware, rather than software change.

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gtani
While we're at it:

i know nobody uses wired mice anymore, BUT: why does the wire come out the
top. Don't they realize if the wire came out the bottom (towards the user),
you could position the mouse much closer to the home keys?

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ars
I don't see how that works. If the wire came out of the back it would be in
the way of my wrist.

I don't see how it would have anything to do with the home keys.

Edit: Wait. Do you put the mouse in front of the keyboard? I put mine to the
side. I think most people put it to the side.

