Hi Gary
I use a Nikon D 7000 on a tripod - very important.
Set on A for aperture priority.
I have the aperture set on midway (6.3). You can play around with it.
Focus on Manual on the lens and on the camera base.
Turn off the Vibration Reducer.
Frame the shot in the viewer on the back of the camera.
Turn the manual focus ring right around to one side and take a shot with the remote shutter release.
Turn the focus ring in the opposite direction, about two of the knurling marks . Take a shot.
Keep turning the manual focus ring a couple of marks until you reach the end, taking shots.
After a while, you will be able to reduce the number of shots, but it's a good starting point.
Download the string of images into your computer and select the ones at each end of the focus range and note their numbers.
Open Helicon and open the images file. Click on your first number and then hold the Shift key and click on your last number. That will highlight the string you want. Open them and hit Render.
Select save. Change the image number to aaaaa That will put it at the front of the image string. Select 100%
Open the image aaaaa in your Photoshop etc (I use Faststone) and crop and resize to 800 x 600 for uploading.
Then I go to Irfan and do one Sharpen and you're good to go.
I have to go out now, so I'll check in later to see how you went.
Cheers