If you go bigger then 50 feet on hdmi you will will need an amplifier for the quality loss.
There is no hard and fast rule in regards to lenght and HDMI. It depends on a few factors, including the cable. While a run of 50' will probably need to be amplified, runs of 35' might need it as well.If you go bigger then 50 feet on hdmi you will will need an amplifier for the quality loss.