Image Quality Deterioration

Hi,

I'm importing in a scrolling window screenshot. I want to mimic a live environment for simulation practice. However, as it's a scrolling window, it's dimension will need to exceed the story height. As a result the quality of the image has degraded considerably. I've tried to change the story size to the largest height in 16:9 ratio with no luck; the image is remains blurry. 

Is there any workaround? As it's a scrolling window, I can't swap it out in the build. I need the full screen without the degradation in image quality. I'm on SL360, the latest build.

Thanks!

Ciara