With a Macro lens, you're supposed to get SMALL detail in the pic. The point of a Macro is to do like you did with the last picture.A macro allows you to get such high detail. Try doing that same picture as the last one with the 18-55mm kit lens on the Rebel. Your camera won't be able to focus unless you're about 18 inches away. With a Macro, you can get incredibly close, and yet still have the lens focus properly.
If you want something that will encompass the whole snake, look at a wide angle lens, that can go 17mm or less, such as a 12 or 15mm prime lens.![]()