looks like the picture is warped xDGuitars are imperfect instruments. There was an attempt to fix such problems all the way up the fretboard. They're called "true temperament" frets, and they're the squiggly frets that honestly, don't see a whole ton of use out there. The tried and true method is to intonate 12th fret fretted notes to exactly match 12th fret natural harmonics using the most accurate and reliable tuner you can. There are some who also swear by "sweetened" tuning, which is configuring your modern electronic tuner to a few cents +/- depending on the string.
It's also possible that you have a flat spot on a fret or two?
Quite a bit, I only noticed it today.What Ed Said (tm). When you're well north of the 12th fret, then it's possibly something to do with the level of the frets. Is it out by a lot or just a little ?
Hmm, those are good suggestions. I'm gonna look up a guitar tech I think.TBH, I have very little experience with expensive guitars (ie: a squire strats have been about the most expensive guitars I've worked on). With cheaper guitars, the fret work is often not so good post the 12th fret, you tend to see this more obviously as fret buzz and intonation issues (I guess they don't expect people to play above the 12th fret) ? However, I can't say about good guitars as I've only played the odd couple in a guitar store that were neither set up or clean..
I would say your two choices are:
1) Intonate accross the whole neck (so that they'll all be a bit out, but no end is "majorly" out)
2) Get a good guitar tech to set it up and do the fret levelling etc.
Ah Gotcha, usually with high action above the 12th you can get intonation issues because of that - I've had a few students with Guitar's not set up quite right and they've had that issueKinda low really