WFM icon FieldMonitor: Controls copyright © 2018 Adam J. Wilt  
A wireless video monitor for iPhone
This page describes FieldMonitor version 4.3 and later. Earlier versions are similar but lack some controls and have others under different names.

The Source Screen has controls to monitor a source (view its video feed), reload the list of available sources, change settings, and view help.

The Monitor Screen has controls to change how the picture is displayed, how ’scopes and markers are shown, and camera controls for controllable cameras.

Source Screen

Settings menu

Tapping Settings on the Source screen displays the Settings menu:





Monitor Screen

Display settings - Hide panelHide adjusts which onscreen elements are hidden when the screen is tapped. Use screen taps  to quickly declutter the screen or toggle focus assist, ’scopes, false-color, the current LUT, and/or markers. Screen taps only hide or show elements that are already turned on: the current ’scope(s), the current markers, etc. So, for example, if you have all markers turned off in the Mark controls, a screen tap won’t turn them on, and a screen tap only hides and shows a ’scope if that ’scope is already enabled. By default, two sets of onscreen controls are affected by screen taps:

Display settings - Scope panelScope controls the engineering ’scopes: their types, layout, and display options.

Marker controlsMark controls image markers: framelines, masks, grids, center marker, and a custom crosshair.

Marker colors

Image controlsImage controls focus assist (camera sources only, not Teradeks) and image geometry.

Level and LUT controlsLevel (only available for camera sources) is used to apply monitoring LUTs and to adjust FieldMonitor for Panasonic image levels.

See About Luma Levels for more details.

False Color controls

Camera Controls

Panasonic and Sony Wi-Fi cameras are supported with a basic set of onscreen controls for exposure, color, focus, and zoom. By default, tapping the screen hides the controls; tapping again brings the controls back (you can turn this off in the Hide settings). Depending on the camera’s operating mode and on-camera settings, different controls will be shown at different times, and the available control options will change.

FieldMonitor with camera controls

When the Wi-Fi network is congested or the signal is weak, camera commands can be delayed or dropped. If “network timeout” appears onscreen, it is likely that commands won’t get through. Wait until “network timeout” disappears before trying to control the camera. If you frequently see “network timeout”, try some of the networking fixes discussed on the support page.

About Luma Levels

Sony cameras always record video clips with levels ranging from 0% to 109%, and FieldMonitor’s ’scopes are calibrated to that range. Sony’s HDMI output is also always 0%–109% when recording video, and in standby when the camera is in movie mode. In still-photo mode, the HDMI range is from -7% to 109%, but it changes to 0%–109% as soon as you start recording. FieldMonitor’s ’scopes  always display the image in the 0%–109% range, so that the ’scopes can be used for previewing video levels regardless of what mode the camera is in.

For Panasonics, things are considerably more complicated...

Panasonic video can be encoded with a variety of “Luminance Levels”, spanning different numerical ranges within their 8-bit (or 10-bit) signals. For example, an 8-bit “full swing” signal records black at a level of 0 and white at a level of 255, just like a JPEG image does. A “studio swing” signal puts black at a level of 16 and white at 235, the black and white levels of a Rec.709 video signal. It's also common to find “extended range” signals with black at 16 and white at 255.

In 10-bit modes, 0–255 translates to 0–1020 or 0–1023; 16–235 is 64–940; and 16–255 is 64–1020 or 64–1023 (Panasonic displays it as 1023 in the GH5’s menus). FieldMonitor always uses 8-bit terminology regardless of how your camera is set up.

Panasonics default to Luminance Levels 16-255 when recording video. If your camera does not have a Luminance Levels setting, it uses 16-255.

Cameras like the GH4 and GH5 offer all three choices when set to MOV format. In AVCHD or MP4 modes, only 16–235 and 16–255 are available; in V-Log L only 0–255 is used. Other cameras like the G7 offer 0–255 and 16-255 options.

When shooting stills, and (usually, but not always) when in Creative Video Mode but not recording, the camera uses 0–255.

Are we having fun yet?

Unfortunately, Panasonics don’t tell Wi-Fi apps which Luminance Levels are in use. In addition, the camera’s images transmitted over Wi-Fi will use different levels settings in standby and in record, and those levels will vary depending on whether the camera is in Creative Video Mode and whether it’s feeding video over an HDMI connection—and the camera doesn't communicate that information, either. Instead, you have to manually set FieldMonitor to match how your camera is set up (yes, this is an annoying, confusing hassle: I'm sorry, but there’s nothing I can do to fix it other than to give you manual controls).

FieldMonitor offers four luma ranges in its Levels settings, so that the measurements made in standby match those made while recording. These settings tell FieldMonitor how to adjust the Wi-Fi image so that its levels—and those of the ’scopes and false-color displays—are always correct:

In addition, you use two switches to tell FieldMonitor whether the camera is in Creative Video Mode (the mode-dial setting with the movie camera), and whether or not you’re feeding live images out HDMI.

If the settings on the camera and in FieldMonitor don’t match, image brightness and contrast, ’scopes, and false-color overlay will change when you go from standby into record or vice versa. (You can test your settings by aiming the camera at a high-contrast scene with clipped whites and deep blacks and watching the WFM as you start and stop recording: the highest and lowest levels seen on the WFM will not change when going between STBY and REC if FieldMonitor is set properly).

If you're worried about mistakes, set any of FieldMonitor’s ranges other than Legal. The ’scopes and false-color will be correct whenever the camera is in record mode (though they may be incorrect in standby mode) and they'll show you exactly what levels are being recorded or sent out HDMI.

© 2018 Adam J. Wilt.  Last updated 2018.01.03