JVC GY-HM170 Camera

Getting the Focus Right

Every shot you get must be properly focused, which is crucial in any professional production. Soft focus shots, unless used for artistic effect, will not be accepted under professional standards. 

To focus a telephoto lens, you must first calibrate it.

Make sure the lens is set to MANUAL FOCUS first – press the AF/MF button on the lens and check to make sure that MF is displayed in the monitor.


Zoom in all the way on your subject and focus by turning the focus ring on the lens until the image looks sharp. Zoom out and compose the shot to the desired framing. Each time you move the camera, it will become necessary to calibrate the telephoto lens.

The large ring located on the lens is the Focus Ring. 

CAUTION: In most situations, using the Automatic Focus is not recommended simply because the camera might shift the focus during recording, and this could ruin the shot especially if it’s an interview.

Getting the focus right means having to judge the focus properly. You might think you can judge the focus using only the LCD monitor, but it’s actually impossible to rely on this 720p display to get true focus. That’s because the LCD Monitor doesn’t have enough pixels to render the image sharply. Focus errors are more obvious in high-definition, but fortunately there are ways to get the best focus possible. 

Focus Assist

Press the F. ASSIST/1 button (located on the lens) to enable Peaking, which draws outlines (in blue or red) around objects that are in sharp focus. Peaking works during recording, but the outline is not recorded into the image. 

Above is an illustration of how Focus Assist works. Turn the focus ring - the image is in focus when you start to see blue outlines appear on edges in the subject. 

NOTE: the “1” in F. ASSIST/1 denotes USER 1, which is a button that can be assigned to other functions via the MENU. 

Expanded Focus

This type of focus assist magnifies the image to show you more detail than in the full frame view.

Press the EXPANDED FOCUS/8 (the “8” denotes USER 8). 

This button is located just forward the zoom rocker on the right side of the camera. 

When EXPANDED FOCUS is selected, the word EXPANDED (in yellow) is displayed in the monitor and the centre portion of the image is magnified.

Pressing the EXPANDED FOCUS button again will restore the image back to normal viewing

The magnified area is not recorded into the image itself. 

Viewfinder Eyepiece

You can optimise the focus better if you can see the image clearly without interference from the lighting in the environment. Make sure to adjust the eyepiece corrector (dioptre) to your eyesight before you start focussing the lens.