Sketch from picture, calibrating issue

[eisenmanguitars]

I am attempting to make a replica pick guard for a guitar.  My first attempt I took a picture of the original, with a ruler in the picture, calibrated 1 in based off of the ruler, and it seems like it stretched somehow.  Like the bottom half elongated, see the picture of the two pieces.  Attempt number two, while sketching I started checking dimensions, and everything lines up until you get to the right hand side where I have to fudge the drawing to stay within the dimensions of the original. Almost like the other side is skewed now, see screenshot attached.  Same thing happened recently when I traced the shape of an object I wanted to inlay, took the picture with the ruler, one of the dimensions ended up skewed.  Suggestions? Many thanks.

[g-andresen]

Hi,

images differ from the original due to the perspective of the shot.
Calibrate the canvas, trace roughly and create the shape using real dimensions.

günther

[eisenmanguitars]

Gunther, thank you for taking the time to respond. I wonder if there is another issue possibly, because the picture I took for all three attempts was straight on.  Even if I was taking the picture at such an angle to produce this much variation (.120") it would end up being smaller, not bigger.  Respectfully, I hope there is another answer.

[g-andresen]

Hi,

Maybe an individual scaling after calibrating will help?

günther