<html> <body> H'mm, I remember this when I was first learning to tune aurally.  My wife's grand backed up to a window.  I could see strings sharpen up together.  I can still see wound strings come into phase by just watching them.  The little ones are harder for my eyes.  And I do use an ETD but don't spend any time watching it when putting unisons together so I get to see this every time I tune a piano in a well-lit environment, not too often in south Texas where dark is associated with -cool-. :-) Andrew Anderson At 09:55 PM 9/19/2007, you wrote: <blockquote type=cite class=cite cite="">I for one found it very interesting.   A few years ago I I saw string shadows during tuning for the first time.  I was amazed at the amount of deflection of the tenor strings.  For some reason, it is not apparent at all if you only watch the strings. Jurgen Goering Piano Forte Supply (250) 754-2440 info@pianofortesupply.com <a href="http://www.pianofortesupply.com"> http://www.pianofortesupply.com</a> On Sep 19, 2007, at 17:32, pianotech-request@ptg.org wrote: <blockquote type=cite class=cite cite="">I was really hoping someone would find the shadow thing interesting, which is what the post was about, rather than the obvious direct sunlight thing. Ron N </blockquote></blockquote></x-html></blockquote></body> </html>