There are two ways of getting your pictures in focus. You can leave the focus on AUTO and let the camera do it for you or you can adjust it manually.
THE TROUBLE WITH AUTO FOCUS ... is that it doesn't work well under the following conditions:
When the subject is not in the centre of the picture (particularly when there are moving objects in the background)
In low light conditions
If there is a bright light behind the subject (e.g. a window)
When the subject is bright (e.g. a car with its head lamps on)
When the subject is of low contrast - walls, the sky
If the subject is made up of fine repetitive patterns
If the subject is behind vertical bars or a chain link fence
When another subject passes between the camera and the point of interest
The good news is that Sony have provided two extra features to help you with manual focusing...
FOCUSING HELP …
1. PEAKING works by emphasising sharp edges by giving them a little added zing in the viewfinder and LCD screen only. Peaking is usually white and clings to sharp edges to emphasise they are in focus. If you are finding it difficult to see the peaking then you can change its colour (red, white or yellow) and level (high, medium and low) in the camera set menu.
2. The EXPANDED FOCUS button will zoom the picture in further to help you check focus. This only works in STBY mode and is not available when recording.
When you start to use the camera you will probably use auto focus. However, with all the above restrictions, I hope you'll want to use the manual focus all the time. Your pictures will look more professional once you get the hang of it.
Set the FOCUS switch to MANUAL
Zoom in as close as you can to the subject (for a person zoom into their eyes)
Press the EXPANDED FOCUS button to zoom the picture in further to ensure focus is correct.
Turn the FOCUS RING , at the front of the lens, to get the picture into focus
Zoom out to frame the shot.
ZOOM IN.... FOCUS.... FRAME UP
... Alternatively
Set the FOCUS switch to MANUAL
Zoom in as close as you can to the point of interest.
Press the EXPANDED FOCUS button to zoom the picture in further to help you check focus.
Push the PUSH AUTO button. This time the camera will momentarily go into AUTO FOCUS .
Once in focus release the button to resume MANUAL focus mode.
Zoom out to frame the shot.
Do be aware that these two techniques are not foolproof. Because these sorts of lenses do not track perfectly (ie they will not stay in focus on the point of interest if you zoom in and out repeatedly). The camera uses look up tables to work out where they focus should be once it has zoomed out and this method is not 100% accurate. Which is why - if you are shooting an interview try this method which does not require zooming....
Manually focus the lens to a distance of one metre (the hyperfocal distance). As you turn the focus ring it will tell you once you are focused 1m away.
Zoom out as wide as you can go – this is important – and stay wide for the whole time you are recording
With this method you are focusing on what is called the HYPERFOCAL distance. When you do this, the depth of field extends from half the hyperfocal distance to infinity. In other words your subject will stay in focus even if they move from 50cm from the lens - all the way to infinity. However, this ONLY works if you stay zoomed out. If you zoom in you will probably go out of focus.
If you want to know more about hyperfocal distance calculations I recommend you go to