A little research unearthed a high powered LED light, the LED Lenser P7, which is 200 lumens. I was able to use this to highlight the focus point. It helped a little but it was still hit and miss. Many images were not right and it took time.
Then I chanced on an article describing on how to use Live View on the Nikon to get a very accurate focus. I gather there is a similar feature on the latest Canon DSLR camera, but you will need to research this yourself. However, this article may help.
For the Nikon the process is very simple. First set the camera on a good solid tripod.
- Set the camera to Manual Focus. The switches 1 can be found on the left of the camera. Flick the switch from AF to M.
- Press the Lv button 2 which can be found on the right hand side of the view screen. The image in the view screen will change to show what the lens is pointing at.
- Use the Zoom button 3 the zoom in.
- Use the multi selector control 4 to move around the image.
- Use the manual focus ring on the lens to set the focus.
- Finally press the Lv button to turn off Live View. This is necessary if you are using flash to take the photo.
- Take the picture.
An example of using Live View to get perfect focus.