One of the changes likely to affect everyone in Firmware v2.0 are the improvements made to autofocus, which will be most apparent for anyone shooting video at 24p.

Panasonic has worked on the algorithm to make it faster to respond to a change of subject distance but claims to have done this without making it too jumpy, or prone to fluttering (the visually distracting attempts to re-confirm the current focus distance).

If the camera detects that it needs to change does need to be made, it will gently accelerate the focus group then move it more quickly than before, before performing a gentle deceleration as it approaches the point of focus (which using DFD-compatible lenses), to give a quick but smooth response.

Many of the updates in firmware V2.0 are video focused but Panasonic says the more decisive autofocus tracking will benefit stills shooters, too.

With this improvement of the default behavior, Panasonic recommends only adjusting the AF-C customization settings if this behavior does not suit your specific subject.

Another significant AF improvement is the ability to choose where AF Tracking will start from, as you prepare for shooting, rather than having to tap-to-track as the action occurs.

As well as the performance change, Panasonic has also made some changes to various other aspects of autofocus, in response to user feedback. For instance, if an AF point is selected at the edge of the frame, a push of the joystick now results it it wrapping 'round, and jumping to the other side of the frame, rather than you having to navigate all the way back across.

Other changes include the regions selected in Multi AF or Custom Multi AF modes being displayed on the screen while shooting.

Tethered Shooting

An unexpected addition to Firmware 2.0 is the addition of a USB tethering system. Software that recreates all the camera's controls, for both stills and video shooting, will be made available, free of charge, for both Windows and MacOS.

We'll be testing this software at some point in the coming months, but Panasonic tells us it will allow control over essentially all the camera's functions, with plenty of options such as the ability to capture and record to the computer. They also say it's designed to give control over where files are placed as they're shot, so that it can easily integrate into a workflow.

All-I (400Mbps) compression options

As originally promised, f/w 2.0 adds the ability to capture video using All-Intra compression (where each individual frame is retained, rather than saving only the differences compared with reference, 'I' frames). This takes up a lot more space but allows higher quality results when editing.

Firmware V2.0 brings the 400Mbps All-I compression options for the camera's 4K UHD 29.97, 23.98, 25 and 24p shooting modes as well as for wider format, DCI 4K shooting at both 23.98 and 24p. We'll update the tables on page 6 of this review shortly, to reflect these capabilities.

Although it does not say they are essential, Panasonic says it strongly recommends the use of V60 SD cards or faster. These are cards that guarantee the ability to write at a sustained speed of 60MB/s or faster. Since an average bit rate of 400Mbps means data rates will inevitably sometimes exceed 50MB/s, these are the slowest cards that will dependably work.

Some fast U3-rated cards may be capable of exceeding the 30MB/s write speed they guarantee, but Panasonic says its testing suggests very few actually do, irrespective of the peak speed numbers printed on the cards. Use of these cards risks recording stopping unexpectedly.

High-resolution anamorphic shooting

Another feature promised all along was the use of a larger region of the sensor to shoot anamorphic video. This firmware update allows the recording of video using a 4992 x 3744 pixel region of the sensor (that's 96% of the width of the camera's sensor).

This footage is captured as 4:2:0, 10-bit Long GOP HEVC (H.265) footage at 200Mbps. Alternatively, the camera can shoot 10-bit, 4:2:2 All-I footage at 400Mbps, in its H.264 formats from a 3328 x 2496 region of the sensor.

This mode is primarily designed to be used with an anamorphic lens (a lens with a non-symmetrical projection, designed to squeeze a wide horizontal field-of-view onto a non wide format capture medium), with the expectation that it'll be horizontally stretched back out to a wider format (de-squeezing).

With a 2x anamorphic lens and the camera's ability to use most of its sensor area, you can make maximum use of the camera's image quality

The larger format is wider and a lot taller than 4K video. This opens up the option to shoot with a conventional, spherical lens (one with symmetrical projection), with the ability to select a 4K crop from the resulting footage or move the crop around, to give a sense of movement even if the camera was static. (A process known as 'Open Gate' shooting). If you use the full width of the footage, and crop something off the top and bottom to give a 16:9 or DCI-style ~19:10 image, you'll end up with essentially 5K footage.

To help with true anamorphic shooting, the firmware adds stabilization modes designed to respond differently to match the different horizontal and vertical sensitivity of shooting with anamorphic lenses. It includes modes for shooting with either a 1.33x or 2x horizontal squeeze.

The camera is able to show a de-squeezed preview, to make the end result easier to visualize, and can overlay markers for output at different aspect ratios. Here we've simulated the 2.35:1 markers.

On top of this, the camera is able to stretch out the footage in both the on-screen preview and in playback mode, so that it's possible to see how the footage will look, de-squeezed, rather than having to stare at an oddly tall, thin preview. This de-squeezed preview can be output over HDMI if you have a larger monitor to view it on, since it can end up taking up only a thin slice of the GH5's rear screen. This can be used in conjunction with the 'View Assist' function that applies a 'LUT' color and contrast correction to the preview and similarly has no effect on the captured footage.

Finally, the camera gains aspect ratio markers, letting you know where the edge of the frame will be, depending on your output intent. The crop marks can display the limits of 2.39:1, 2.35:1, 16:9 and 1:1 ratios.

Hybrid Log Gamma

Another addition to the camera is the ability to shoot Hybrid Log Gamma (HLG). This is one of the HDR TV systems covered in the international telecoms standard ITU-R BT.2100. Essentially it involves shooting footage with a log gamma curve but nearer to final-image color gamut than most Log footage. It assumes the application of the HLG correction curve, which will present this Log footage as a sensibly rendered image when viewed back on a compatible device.

The GH5 offers two ways of shooting HLG footage: there's a 72Mbps HEVC (H.265) option, designed for simple HDR video capture for immediate playback on a compatible television (the number of which is likely to increase, since HLG is being adopted by both Japan and the UK's national broadcasters for HDR transmission). Essentially a shoot-and-show approach.

Some new TVs, including some Panasonic model can make full use of their greater brightness and bit depth by playing back Hybrid Log Gamma HDR footage.

The alternative is that you can shoot in the camera's 400Mbps, All-I, 4:2:2 H.264 formats, for editing in the non-linear editing software of your choice. Shooting using the HLG color mode will embed a series of tags in the footage so that compatible editors will recognize it as footage destined to be graded for HLG output.

Whichever way you choose to shoot, the camera offers preview modes to allow you to visualize some of what the final footage will look like. Using the camera's View Assist function, you can apply a correction to the footage to preview the final outcome, rather than having to look at flat, grey footage. However, because HLG is designed to be output to 10-bit devices with a wider contrast range than the rear screen of the GH5, you have to choose whether the preview shows all the captured highlight detail or whether it clips some of this and shows the exposure in the mid-tones.

Lock IS mode

Another change to the camera is the addition of 'Lock IS' mode in the camera's stabilization menu. This tells the camera that you're trying to hold the camera steady and won't be attempting to pan. This means the camera doesn't have to constantly try to guess whether the camera was accidentally or intentionally moved sideways and is able to more aggressively cancel-out slight horizontal movements.

Other updates

A series of other small but fixes and feature improvements have also been introduced with f/w 2.0:

  • Improved buffering of 6K and 4K Photo modes, halves delay before re-shooting
  • [Loop Rec] option added for 6K Photo mode (V90 card recommended)
  • Bluetooth shutter release option added to smartphone app
  • Time lapse mode now displays time 'til completion in standby
  • Ratings options, adds metadata ratings to images, recognized by editing software
  • WB Fine Tune changes no longer ignored when K value white balance chosen
  • DISP button can now be locked-out as part of 'Operation Lock' function
  • Additional Fn button options, including Auto ISO Min SS
  • Various bug fixes