4K gives extra sharpness and like I told you in the video lens quality is also quite important. FullHD is still good enough for 100" size. 00:00 How I will test the projectors 02:03 4K-FullHD Compare Footage Dont forget to watch this video with keeping in mind This was not a 2 projector comparison because Optoma UHD 35 is 2-3 times more expensive than LG HF60LS My focus was about sharpnes how good the image looks like if you go 4K specially sharpness Go fo 4K When - you have budget enough - if you are not going to TV + Projector Setup Like Me if it's going to be only device at home - Size is more than 100"" go for 4K - 4K gaming console and gaming is important than you have to pay for that - if you are professional photographer and designer and your eyes are sharp on every detail and you are pixel peeping than go 4K Go For Full HD When - Budget is important limit - you are just casual consumer using time to time - you are more of a tv person - your console is full hd like PS4 or Xbox One - screen size is 100" or less You can ejoy both of the choices when you have projector in your life 😊