How to render a cinematic or a cutscene in Unity?

A while back i wanted to create a cinematic completely in Unity, Something akin to an epic like Blacksmith. What i created was far from epic Amazons Sparring.

The biggest problem was rendering the movie itself. After spending days googling for any info i gave up, created a build and used Fraps to record it. Lost a bunch of frames, somehow my colors lost saturation (this could be related to my encoding the video for YouTube).

A few days ago i stumbled across WaitForEndOfFrame function. I modified the code a bit and was able to capture images of my frames.

 using System.IO;
 using UnityEngine;
 using System.Collections;
 
 
 public class ExampleClass : MonoBehaviour {
     private int count = 1;
 
     // Take a shot immediately
     void Awake() 
     {
         StartCoroutine(UploadPNG());
     }
 
     void Update()
     {
         StartCoroutine(UploadPNG());
     }
 
     IEnumerator UploadPNG() {
         // We should only read the screen buffer after rendering is complete
         yield return new WaitForEndOfFrame();
 
         // Create a texture the size of the screen, RGB24 format
         int width = Screen.width;
         int height = Screen.height;
         Texture2D tex = new Texture2D(width, height, TextureFormat.RGB24, false);
 
         // Read screen contents into the texture
         tex.ReadPixels(new Rect(0, 0, width, height), 0, 0);
         tex.Apply();
 
         // Encode texture into PNG
         byte[] bytes = tex.EncodeToPNG();
         Destroy(tex);
 
         // For testing purposes, also write to a file in the project folder
 
         File.WriteAllBytes(Application.dataPath + "/../SavedScreen" + count + ".png", bytes);
         count++;
     }
 }

To get editor PlayMode to display itself in full screen used Full Screen On Play script.

This allowed me to capture frames in full screen resolution directly from the editor. But my PC isn't powerful enough so I lost frames. I thought of slowing down the game itself to allow for every frame to be rendered, so i tweaked TimeManager default values ( Edit>Project Settings>Time) by lowering them as far as they would go. This worked and i was to able capture every frame, until the Editor froze.So i created the build and ran it. It worked up to a point then it froze too.

Every frame i captured at 1920x1080 was a bit over 3MB, and when everything stopped working i had about 6GB of images.

I'm stuck and out of ideas.

Can anyone offer a solution?