Depends on your vision. My vision is 20/30 and I have an Epson 8700UB. (Should be identical as far as SDE to the 5020.) I have a 138" screen and sit 12' back from the screen. I see no SDE at that distance under any condition. I start to see SDE at 6 - 8 feet. If you have 20/10 vision you might see it at 12' with a 138" screen. if you know your vision you should be able to do the math and figure out where you might see SDE. If you don't know your vision you'll need to demo to be sure.