Twisted Blade?

Now that I've taken some time to get to Murray Carter's books and DVDs I got awhile back I guess I'm looking more critically at my knives, perhaps too critically. When I use his techniques to check a blade for straightness, something doesn't seem right with a couple of my NAS Takedas. I checked about 10 other knives (including Carter, Takamura, Misono, ZK, etc.) and didn't notice this.

With the tip pointing to my face I can see the spine/handle is straight, and I can look at it from the choil and get a nice "choil shot", but if I hold the blade parallel to the floor and look the cutting edge (lined up with the spine), I notice that it is aligned at the tip and throughout most of the length of the blade, but it appears to drop either up or down for the last few of inches towards the heel. It's more pronounced on the Gyuto than the smaller Nakiri. This only appears to be a few mm/degrees (so that you can start to see the actual blade face). I wouldn't have even noticed unless I looked them this way (never did beforehand)

I know it isn't from misuse, but am wondering if anyone else has noticed this with any of their knives and if it amounted to a problem? I was thinking about rehandling them at some point but don't really want to "invest" in a knife if it's a dud.

Thanks

:whistling:

Fellow Takeda users, has anyone else noticed this with the NAS, or with any other knife for that matter? Even if the answer is no, I'm also open to hearing your thoughts on the matter.

Thanks

I don't know why you're trusting your eyes. Take a straight-edge ruler to your knife to both sides. It won't sit completely flush but you'll get a sense as if there is any significant deviation from the middle/straight. Your eyes can sometimes fool you. Both of my Takedas cut straight and true. Which is remarkable considering that the blade is hammered flat.

It has been awhile, and all my Takedas are gone, but the four (?) that I had all had ripples or waves that went in both directions, i.e looking down the cutting edge from choil to tip or looking down the blade from spine to edge you could see the blade lean or twist on several directions. Not like the blade was bent in one direction, but like waves moving in both directions. Interestingly the Takeda blade with the least amount of variation was my Chukka - the biggest hunk of metal of the Takeda's I owned.
And it didn't seem to hurt performance of any if them, but "my opinion" of the Takeda blades I owned was that a) they are rustic, artisinal products (I'd never call them custom), b) that the f&f or QC of the 'whole knife' was near the very bottom of the spectrum, but c) the performance of the cutting edge was outstanding - seemingly among the best of the knives I'd owned.

No worries with my Takeda here but it is short t 170mm.