Lunch with FinePoint

I use the Toshiba M200 daily, mostly with the digitizer. In my experience, I flip to the eraser side all the time, and having that flip from point to eraser be natural is perhaps the #1 concern (and benefit of the Toshiba pen, which feels well-made for that). The pens need to be contoured a bit better, too, to force a user to hold it a certain way. Currently the pen is too round: you end up pressing the aux. button all the time by accident. The Toshiba M200 approach of adding margins outside the display is great, and prevents strange warping of the digitizer cursor I see on other models. Finally, in terms of positive feedback: pressure sensitivity seems plenty for handwriting, and is vitally important to producing readable written text.

Speaking here as a digital paint expert (Tech lead for Alias Sketchbook, Painting in Alias Studio, and Alias StudioPaint)

I have a question for them — why was there no pressure sensitivity on the first generation of HP tablets?

Accuracy is good — but have them try the “ruler test” put a straight edge on their tablet — draw a line. Oh it’s not that straight is it? These things are really sensitive to EM noise. They need to work on that (wacom isn’t that good at this either) — there’s some interesting PRML tehcniques for finding signal in noise that could help them here.

As for what people would use tilt for — where is their imagination? Think about any pen nib that isn’t spherical (pretty much anything more adventurous than a ballpoint pen) — stylus tilt and rotation are necessary to provide a good simulation of this.

To summarize, the channels needed are x position, y position, pressure, x-tilt, y-tilt, rotation (about the axis of the pen)

For decent artistic use, x and y position should be accurate to atleast 1/32 of a screen pixel. Pressure needs at least 256 levels *after* linearization. x-tilt and y-tilt should be accurate to about 1 degree for normal to about 40 degrees — less accurate after that is ok. Rotation should be accurate to 2 degrees. All of this needs to be coming in at at least 100 samples per second, but not more than 150. And the sample rate needs to be known and quite constant (+- 0.5%).

Regards,
Ian Ameline,
Alias Sketchbook Tech Lead.