Adam Dodd

Hi gang, I once worked with a shooter who had an F55 hooked up to a cheap computer monitor and I wonder what type it was and how it would be possible. The camera was shooting 4k I know that for sure but not sure if it was outputting 4k. Any know of a computer monitor that has sdi inputs? Or did he maybe have a converter from sdi to hdmi? Any thoughts or tips for a decent set up that wont cost the earth.. Thanks, Adam Dodd.