This is a really great conversation guys. I would like to add a few more things.
I just took a hard look at the photo that Bruce posted and in my opinion, there are two things going on. There is both poor DOF, and poor focus. If it was strictly a DOF issue, shouldn't at least part of the photo be in focus? I just don't see anything in that image that is in proper focus. The line going across the bottom of the image does appear to be slightly sharper. But to me, it still seems out of focus.
Lets assume that my assumption is correct, for conversation sake. If that is true then that the image as a whole is out of focus, then what are the causes? There are a lot of unknowns here. Was the camera on automatic focus and the sensor couldn't focus correctly? That certainly does happen and my DSLR has problems focusing in on close subjects. Was it manually focused and the optimal focus was missed? Is it a case of camera shake? Or is this a case of the distance being too close for the lens/camera setup? Without knowing more, we probably can't be 100% certain. If I were to venture a guess though, based on my experience, what we know about the type of lens that Bruce used, and the size of the subject matter and its size in the image, I think that he exceeded the operatIng distance of focus. Again, just my opinion.
As I had mentioned earlier, I can relate to the problem that Bruce is having. Greg...you remember my Avenger and the GB that I was part of? When I first started posting photos I immediatly started hitting that focusing barrier that Max is talking about. I could not get in close enough. It was frustrating as all heck. Here I have a 3k rig and I can't even use it. My next option was to do what Jack suggests. Take the photo within the focusing limits of the gear, then crop the image on the computer. Well, that works, to a point. Guess what? There is a limit to that too. You reach a point where you can only crop so much before the image loses its integrity. In short, it looks like garbage. But, in some cases, you can get away with it.
So then, what do I do? Ah...a brainstorm. I position my desk lamp with magnifier over the subject, and then shoot the image through the magnifier. Hey...that works! And it does, if you are willing to accept poor overal sharpness. For the time being I was, and did. However, I soon became very tired of trying to focus my camera through a magnifying lamp. And BTW, good luck with this method if a tripod needs to be involved. Sigh.
Thats when I came to the inescapable conclusion. If I am going to stay in this hobby and be active in posting images, then I need to find a better solution. The rest is history.
Bruce mentioned that he wants to do a WIP. That means he will be doing a lot of imaging, and probably taking many images detailing processes that will be out of the focusing range of the lenses that he has. He will need to come up with a plan to address this or it will become a major frustration.
I agree with Greg about not spending lots of money just to accomplish this one little thing. That is the reason that I resisted it myself, and that I jumped through all kinds of hoops to make things work. There is one caveat to this though. Maybe photography is a hobby for Bruce. In that case, maybe a macro lens makes sense. It could be used in both hobbies. Or, the same being true with the extention tubes.
That is also a great idea, Greg, about the smartphone. I always forget that little nugget. Those can focus pretty tightly too. Lots of options to consider.
Lots of good info there Max.
Bruce...let us know how this works out for you.