  In this paper we show that a negative index of refraction is not a direct
implication of transformation optics with orientation-reversing
diffeomorphisms. Rather a negative index appears due to a specific choice of
sign freedom. Furthermore, we point out that the transformation designed lens,
which relies on the concept of spacetime folding, does not amplify evanescent
modes, in contrast to the Pendry-Veselago lens. Instead, evanescent modes at
the image point are produced by a duplicated source and thus no imaging of the
near field (perfect lensing) takes place.
