I might not always agree with Compuwar, but in this case, spot on, exactly what I would have criticized. I'd like to add a few tips , in case you are interested.
1. Vignetting works sometimes, but generally try to keep the picture clear, especially in B & W, simply because it wears the image down unless there is a very high contrast focus point.
2. Contrast, Contrast, Contrast... in B & W you need to look for contrast. If you have a nice green and a nice blue and a nice red in the color image, in B & W is will just be dark grey, slightly different dark grey and a little bit more of dark grey. B & W needs black and white to work.
3. B & W is an art and not something you learn over night, so whatever Compuwar mentioned, try shooting something else. That one "window" image that had potential, I would also reshoot it. If you do not have a remote flash, try a good other light source (one of those big flashlights with a good sized lamp). or, if that is out of the question a DYI reflector (Aluminum foil for example) that kicks the light on the gravestone just a little higher.
Besides the criticism I would still say it was a good first attempt. But as with all things, time to keep at it and practicing.
Actually an easy way to practice contrast shooting, to see in black and white so to speak, is to take a white and a black cardboard sheet (you can get at some office supply store for very little) and put various lighter subjects on it (white, yellow, red, green pens for example) and some variable darker subjects on the white cardboard. Shoot images and then convert them to B & W. Adjust curves and levels to see what effect it has on the photo in B &W.
just my 2 c.
//FR