Check out my Hartman post Paul. (Maybe its a Kendrick mask I'm using Or a Schiner Disk?
)
I find it a lot easier to focus using the triangular holes. Have a look at the images if you haven't already. Though it may not work as well with a LPI, it seems to have a fairly long lag time/refresh rate I had a bit of a problem with it, but maybe thats just me using the LPI
). Its np with the ToUcam. Pretty much as you do it, half sec to sec later its there.