You are definitely running into the Moiré effect. This was always a concern with broadcast video since the resolution was so low (720x486). The angle of your lines plays a big part in it as well. The only solution is to change the angle, enlarge the pattern or increase the resolution. The image that Beanzvision posted is spot-on. The scaled-down image doesn't have the resolution to resolve the detail and it conflicts with the screen's pixels. This is why top professionals on TV never wear fine patterns on camera. Their clothes will dance with this effect. In this example, notice the farther away the camera gets (lower effective resolution), the worse the shimmering gets? Same problem you have here.