There are a couple reasons the edge in that shot looks a little ragged. One is because it
is a little ragged, lol. It's an edge that has been shaved with and also it's at about 250x (calibrated with an item of known size). If you don't have that level of magnification things always look pretty straight after a decent finisher. On top of that, it's a high speed steel razor - which doesn't cut cleanly with natural stones - diamond or CBN are needed to get a very clean edge. Here is a shot of the exact same razor finished on diamond:
Attachment 229997
I don't judge too much by edge appearance really, just checking that the apex is keen. That band of light in the apex shots is only a few microns wide. I can't tell you how many times I thought an edge looked awful at this magnification but shaved very well. A scope is a tool, not an arbiter of edge quality.
For lighting the apex I use a focused beam LED that basically collimates the light so it's all traveling the same direction in a straight line. I light up the edge from perpendicular to the apex with the light shining directly at the apex. The razor is positioned so that the bevel is parallel to the scope lens.