[Tfug] Panel installation height?

[Bexley Hall]

Hi,

On 10/28/2012 2:21 PM, unixmito at SDF.ORG wrote:
> You might be overthinking this one.

*Me*?  Overthink??  ;-)

> Having taken PT for a massive injury,

Bummer!  :<

> any thing placed right below the
> chin (perpendicular to the neck/clavicle) is the path of least resistance
> (taking physiology into account.)

Yes, it's easy to bring (and hold) your hand up at your chin.
But, a panel mounted on the wall is different than hand at chin.
Consider, you would probably stand a foot or so *from* the wall
(so your eyes could focus on the imagery and your hand would be
free to access the panel).

Since you can't rest your hand *on* the panel (for support),
you still experience a load on shoulder as you keep the hand
in that position (and, you are unlikely to let the hand drop
to your side "between keystrokes").

There are several issues that come into play ("overthinking"?).

A pure display function can be sited with only visual path
being of interest.  This tends to lead to higher mountings
as you fit for a slight downward gaze from eye-height (at
nominal viewing distance).

When you add the touch aspects, height wants to be compromised
because lifting hands up to a comfortable *viewing* height is
more work/strain.  This puts downward pressure on the height
selection.  Of course, as you move down, you pull the display
out of the ideal position for viewing (which can also have an
effect on the visibility of the display's content, depending
on the technology used for the display!)

However, you also have to take the vision characteristics of the
users into consideration.  E.g., older users tend to need
corrective lenses for "up close" viewing (and, you can't get
too far from a display panel if you want to be able to read
any fine details thereon).  Those with bifocals will tend to
read out of the bottom of their glasses.  As you raise the
height of the display, you force them to tilt their heads
backwards in order to bring the display into that lower part
of their vision field.  I.e., increased age drives the visual
sweet spot down, as well.

You also have to take into consideration the types of users
likely to interact with the panel.  I'm sure you can recall
seeing a son/daughter/niece/nephew *stretching* to reach a
light switch at some point in their young lives!  :>  More
downward pressure on the height selection?

But, this also affects people with disabilities.  E.g., in
a wheelchair, maximum (height) reach is about 54".  And, at
that, the user would be *looking* upwards to see what he was
touching!

> 5" 10" seems to be a national average
> (http://en.wikipedia.org/wiki/File:Galton-height-regress.jpg). The least
> amount of muscular utilization at an average height for an average human
> (both male and female).

After all these "issues", I finally decided that I really only have
to worry about *two* people.  No kids.  Friends and neighbors
(some being very short, etc.) shouldn't be mucking with this stuff.
And (touch wood), neither of us appear headed for a wheelchair
any time soon[*].

So, I just went at it empirically.  My first pass was ~62 inches, CL.
Given the small display size, this comfortably kept the entire
display in the lower half of my visual field (looking "up", even
without moving your head, seems to be less comfortable than "down").
And, at a comfortable viewing distance, it kept my hand(s) at
a reasonable height when interacting with the panels.

Of course, history teaches that I always aim too high... :>  So,
I started lowering the panel until it started to fall below my
comfortable viewing area.  At 58" CL, I started getting fidgety
so that's where it ends up.  :-/

--don

[*] And, that case is covered by other mechanisms!