Bit of a clunky way to do it but if Im using my old Digital SLR (which has a naff lcd display on the back) I take a shot on manual focu then view the shot on the viewfinder and zoom into the picture, and see if it looks blurry in close and see if the focus was right. Make an adjustment and take another shot. Like I said its not perfect but its the only workaround Ive found with it.