Parallax
Last updated
Last updated
Parallax = an apparent inaccuracy in pen tracking due to physical separation of the display panel from the surface the tip of the pen is touching. The apparent inaccuracy will change as the position of your eyes changes relative to the pen on tablet.
Parallax is discussed in great detail in this video (https://youtu.be/M4rEk_RNBrM)
The cause of parallax is a physical separation between the display panel and the tip of the pen. Whenever there is any distance between the two, some parallax will be introduced. The greater the separation, the greater the visual effect of the parallax.
In drawing tablets this is caused because there the glass that covers the display panel has some non-zero width.
Depending on where your eye is, the what you see the tip of the pen pointing to is different.
Compare this line of sight
To this one:
Clearly parallax makes you see different things.
Additional parallax can be introduced by:
anti glare matte films that applied on top of the glass.
protective films on top of the glass
touch senser between the glass and the display panel
The way to reduce parallax is to minimize the distance between the tip of the pen and the display panel
Here is a thick sheet of glass with lots of parallax
Compare it to a very thin sheet of glass with much less parallax
Especially in older models of pen displays and pen computers, there is an air gap between the display panel and the glass. This air gap itself is another source of parallax. Replacing the air gap so that it is replaced with an optically clear adhesive can improve the parallax.
learn more here: Lamination
It is always preferable to by a drawing tablet that has a laminated display.
The Apple iPad Pro has the best (lowest) parallax I've ever seen. I would rank it as EXCELLENT.
Parallax introduces an apparent visual inaccuracy.
Consider these two cases:
(1) A pen display that tracks the pen position perfectly. If there is any distance between the display panel and the where the tip of the pen touches the tablet (for example due to glass) then there will be some amount of parallax - an apparent inaccuracy.
(2) A pen display that does not track the pen position accurately but also has NO distance between the display panel and the pen tip. Such a pen display would have NO PARALLAX effect but clearly their will always be some real inaccuracy.
So we see that inaccuracy comes from two sources:
apparent inaccuracy from the parallax
actual inaccuracy from the tablet EMR sensor
Very often, people refer to any visual discrepancy as "parallax" but that is an incorrect usage of the term. They should only be using it when the position of their eyes in combination with the physical separation of the display panel and glass are causing the discrepancy.
Generally, users of drawing tablets do not want to see parallax.
However, some people (perhaps not many) even find parallax to be slightly beneficial. For them, they like to see where they are drawing a stroke on the display and having the pen tip be a little displaced from that position makes it easier to see that point.
These three pen displays show very good parallax. Notice that the one of the left is a $3500 pen display and two on the right are entry level $300 pen displays. All these displays are laminated/
Compare the laminated pen display on the left to the unlaminated pen display on the right. Disregard the blurry image - that is an issue with the photograph itself. Notice how far away the tip of the pen is from the tip of the point.
Sweet Monia: What is parallax? And is it really bad in a pen display like Cintiq or Kamvas?(https://sweetmonia.com/Sweet-Drawing-Blog/what-is-parallax-and-is-it-really-bad-in-a-pen-display-like-cintiq-or-kamvas/)
