On a frame by frame scanner, the difference between SD vs. 1536p is obvious. On older transfer systems in some ways the SD transfer can be more desirable because in HD you simply seem to have a more obvious grain and the softer SD transfer can seem more pleasant to look at. With a true scanner at 1536p, there is a bit more obvious grain as well but there is also a more obvious clarity to the image than the SD version of the same footage. It may come down to taste on some level but we have confidence that in general HD or our even higher resolution 1536p, is a better way to go. On the off chance, should you not like the 1536p version of your film transfer it can be easily down converted to SD. That doesn’t doesn’t work the other way around.