Explaining switch of research interests in Statement of Purpose For most of my Masters studies, I worked in the area of Quantum computation and wrote my thesis on that. But following that, I lost my interest and switched to Computer Vision and worked as an intern for a few months. Now I plan to pursue a PhD in the field of Computer Vision even though my Masters thesis was on a different topic. How should I convince the admission committee about this switch ?

I had published 2 papers while working on Quantum computations (one from my Thesis and another one as a student job) and 1 in Computer Vision from my internship. But I was not interested in Quantum computations because it consisted mostly coding and there was no hardware to work on (at least in my university). Whereas computer vision is a branch I am very comfortable with since I directly get to see the impact of the changes in algorithm visually. I also have very good grades in the area related to computer vision. But I cannot really frame a convincing story as "visual feedback" is not enough concrete to convince a potential guide. 

Please give me your inputs. Thank you.
You don't have to convince the admission committee about the switch.

You do have to convince the admission committee that you are able to complete a PhD in Computer Vision.

Work out what skills will be needed, and present your evidence that you have those skills.

Work out what knowledge will be needed as a prerequisite, and present your evidence that you have that knowledge.

Work out what the other pre-requisities are (funding, contributing to the internal life of the department, whatever), and present the evidence for that too.