Absolutely. It's also worth buying a light source with an adjustable arm. Changing the angle of lighting helps spot additional defects, stress lines, thumb prints, etc.
I also recommend inspecting each book at least 3 times (on 3 separate occasions) to catch all the defects. Most of the books I send to be CGC graded (ranging from 1979 to 2003) are from my original collection and another original collection I purchased a while back. I'll typically start with 100 books and easily whittle it down to 40 or so after a quick inspection. Next day I'll inspect each of the remaining books very carefully, which eliminates another 20. On the third day I'll do a detailed inspection again and am always surprised to find additional defects I didn't find the night before.
One other thing to note is that some minor defects (like one light corner bend or minor stress line not braking color) are allowed for 9.8 books. Sometimes using high level equipment could lead to over-grading as well.