I get quite a few questions regarding lighting engine. I personally played the OG Vanilla and loved it, It was the only Dark souls game I had played pre-elden ring. I started this mod to re-experience DS2 after finishing elden ring and definitely it didn't look how I remember. Anyways here is some comparision shots.
1st Image is OG Vanilla, 2nd Image is LE Default, 3rd Image is Scholar. 4th Image is LE with "Scholar" Filter(40-50% Contrast, extra exposure. Takes about 30 seconds).
Additionally Scholar also adds a green tint filter to things. You can see in Amana the flowers turn from Blue into Teal.
BTW I don't even know what ADP does until I played Elden ring and learn about iFrames, but I have completed the OG Vanilla many times and loved it. I was not even aware of such things.
Anyways LE Default is more close to Vanilla in terms of vibe, contrast and color grading. It also works with Path tracing much better due to the fact that Diffuse Global illumination is not crushed by high contrast.