Thanks Glenn,
I've got tomorrow off so I will set it all up again on a three dimensional target that I have and see where it is focusing. . .
I will let you know how things go with follow-ups as things progress. . .
Bruce

Use a fast shutter speed and camera/lens on solid tripod to avoid any movement contributing to the result. Failing that, use flash but indoors where there won't be a lot of non-flash light contributing.

Glenn,
I hadn't thought of the indoor/flash combination, I have done the previous work indoors but with additional lighting, not flash.
Wouldn't the flash give a nice strong 'light' on the target and highlight the lineal graph to see if there is front or rear focus?
Bruce

Main reason to use flash is the flash pulse is so short that it should remove most or all risk of introducing any blur due to camera movement. That's also why you should use a high shutter speed if doing this outside (eg faster than say 1/2000 sec)

Cheers
Glenn

Hello again Bruce,
I assume you're thinking about using something like Michael Tapes Lensalign. This will show you if your lens is back focusing or not. Your camera is smart enough to know what lens you are using by its number and will only apply the changes you make for that particular lens, or lens combination, if you are testing it with the teleconverter. I expect you'll be starting at the zero adjustment setting and be able to dial either 10 or 20 steps to move the focal point backwards or forwards. With the lens align program, it will get you to take numerous exposures at the same setting and compare the results, and from this you will get a solid accurate setting. However, the thing to remember is you can just dial your camera back to zero if you're unhappy with the outcome. There's no risk involved.
By the bye, if you use a tripod, the shutter speed won't matter that much. I use a long exposure and a 5 or 10 second time delay. It gets rid of any possibility of shake from several possible causes- the shutter, the cable interfering with the camera, or human hands.
As for giving it to Nikon to work on, I found them very slow, but excellent at what they do. I won't expect any problems. Our local Nikon chap in SA is exceptional too.

Les Peters wrote: By the bye, if you use a tripod, the shutter speed won't matter that much. I use a long exposure and a 5 or 10 second time delay. It gets rid of any possibility of shake from several possible causes- the shutter, the cable interfering with the camera, or human hands.

I agree that a 'long' exposure will work on a tripod provided a delayed shutter release is used. However, there is still a risk here that the mirror flipping up will shake the camera - even on a tripod. For a long exposure, this brief moment of movement probably won't affect the result but if you used a 'medium' shutter speed, it could well cause visible motion blur. By 'medium I mean something roughly between 1 second and 1/1000 sec.