# Eigenfaces VS Deep neural network for classification

I just saw a video from Washington University where professor Steve Brunton explain how to use Eigenfaces for classfication e.g image recognition.

Eigenfaces is really simple and does not require any training or parameter tuning etc. He show that it took just few seconds and then it's done. Super fast.

Eigenfaces was solved by using Singular value decomposition.

$$A = USV^T$$ Eigenfaces classification

So what is best if I want to have some kind of simple image classification? Should I spend time and energy to train a deep neural or should I focus on eigenfaces? Eigenfaces is legacy, but it's still not bad, right?

Is it easy to train a deep neural network with multiple pictures? Or is that a hard task? As I see other people doing deep learning, they just cook up someting and then they have solved world problems. Sounds too good to be true right?

In what situation do you prefer eigenfaces over deep neural network? No?