Re: Optical spacing -- no more?

[Abraham Lee]

On Thu, Jul 10, 2014 at 3:39 AM, James Harkins <address@hidden> wrote:

Something I've been wondering about for awhile... lilypond.org boasts of "optical spacing" for notes with alternating up and down stems, but it seems this feature has been lost somewhere (or disabled by default). In this example, it's quite plain to my eyes that the stems are not equally spaced within the bars. \version "2.18.2" \relative c'' { e4 c, f' d, g' e, a' f, } Which is correct -- the website, or LP's behavior? hjh _______________________________________________ lilypond-user mailing list address@hidden https://lists.gnu.org/mailman/listinfo/lilypond-user

James,

I would have to disagree with you. I think the notes look very nicely spaced. I think you are misunderstanding what "optical spacing" implies. It doesn't mean that the stems will be placed equidistant from each other. That would look awful because of how far that would push the noteheads out of place! Rather, it's a balancing act of how much whitespace our eyes perceive due to how close the stems AND noteheads appear to be when the stems are in opposite directions. An up-stem, down-stem pair will tend to push each other farther away _a little_ because the eye wants more whitespace between them. A down-stem, up-stem pair will tend to pull towards each other _a little_ because the eye wants less whitespace between them.

Attached is a pictogram of the paper columns of your snippet. Notice the difference in how far a down-stem notehead is from an up-stem notehead (2.66 staff spaces) and vice-versa (3.30 staff spaces). They are not equal because of the optical spacing engine. If they were equal (at 2.98 staff spaces), the up-stem/down-stem pairs would look too close together and the down-stem/up-stem pairs would look too far apart, as exemplified in the LilyPond essay:

http://lilypond.org/doc/v2.18/Documentation/essay/engraving-details#optical-spacing

In my opinion, I'd say the optical spacing is alive and kicking!

Hope that helps.

-Abraham

optical-spacing.png
Description: PNG image