Originally Posted by
ace
On the contrary, it is a good question because having a bright light and a loupe doesn't get you very far when you don't know what you are looking for. With a 10X loupe, several things will be apparent.
1. You'll be able to visualize the sides of the bevel, see how regular it is and whether there are residual scratches left in it by earlier stones. I wouldn't worry about the scratches because I would claim they won't affect the shave at all.
2. You will be able to see if there are any little "dents" or "nicks" in the edge. These would normally show up as reflections if the edge is held upward toward the light, but sometimes they are small enough to be invisible with the naked eye. They are signs of damage that has not been removed by honing and thus the bevel has not been completely set.
3. You can literally "see" whether the bevel extends through the edge, meaning the bevel has been completely set. You will often find evidence of prior bevel sets, double bevels, incomplete bevels, etc.
4. The value of visual testing is that, at least at the start of your honing career, you will learn more by seeing the bevel and edge than you will from the various tests already mentioned. This is not because they are not good tests, but because they require considerable experience and "feel" to make judgments about the edge. You will develop that eventually, although I have given up on all that and just look at the edge.
5. While unfortunately controversial on this forum, if you practice, perfect and use the HHT by really working on it, it may become your best "test". It takes time and practice and usage of a variety of hairs. Most on here have used it one time, couldn't get it to work and have given up on it. I worked at it until I understood it. Without it, I would not know when to stop honing, when I had done enough. I can now take any razor, a couple hairs, and tell exactly how well that razor will shave. When a razor does well on MY HHT, it always shaves beautifully. It took me a month of practice to get there, but now it is infallible for me. I check bevels by looking to see if they are complete, and I check edges with MY HHT. If you need help with this, you can PM me.