The virtual horizon (or virtual level) tool is one of the most useful overlays for composing your shots. Here's how it works on the Sony a7R IV.
Virtual horizons, or virtual levels, are one of my favorite overlays that a made possible by the live view screens and electronic viewfinders of modern cameras. They’re incredibly useful for landscape and architectural work, and the better ones can tell you not only whether the horizon is level, but also the pitch (ie. whether it’s tilted up or down). And they’re much easier and more accurate than the old-school approach of putting a bubble level in the camera’s hot shoe.
There are two areas in the Sony a7R IV’s information displays where you can find the virtual horizon.
One is part of the everything-but-the-kitchen sink display screen. If you haven’t altered the default information displays, you can get to this by pressing the DISP button on the back of the camera. That’s the top of the dial on the back panel. Each time you press that, it cycles to the next display screen.
The drawback of that screen is that you can’t see what you’re shooting. It’s also only available on the back screen, not through the viewfinder. But it can be particularly useful for tripod shooting, especially at night to show you all the settings you’re using.
For live composition framing, there’s another option that you can use. That’s a true overlay, in that you can see the live view as well. And it works on both the back screen and the viewfinder. So for most users, this is probably going to be the more useful option more often.
The virtual horizon is pretty intuitive. When the camera is level, the markers turn green. This, for example, is what it looks like when the camera is level and flat. Both sets of markers, in the center and on the sides, are green.
This is with the camera level sideways (ie. not rolling) but pointed down. The side markers are green, but the vertical markers in the center at orange and towards the top of the gauge.
This is pointed up.
And this is the camera not tilted up or down but rolling to the right.
If you switch the camera to portrait orientation (ie. vertical), the virtual horizon gauge will automatically adjust (there’s a glitch with the HDMI output where it doesn’t display properly, so I haven’t gotten a screenshot of it, but it adjusts correctly on the back screen and the electronic viewfinder.
These overlay screens are enabled by default, but it is possible they’ve been deactivated at some point. That’s because the a7R IV lets you choose which informational display screens are available.
You can find this option under:
Settings (the toolbox icon) > Page 7/11: Display/Auto Review1 > DISP Button
You can then choose whether you’re customizing the viewfinder overlays or the back screen (monitor) overlays. The options are similar, but you don’t have the “For viewfinder” option when viewfinder (that’s the everything-and-the-kitchen-sink display that blacks out the live view and therefore doesn’t make much sense for the viewfinder).
For the overlay with the live view, you want to make sure that the Level option is checked.
The virtual horizon complements another screen overlay well: the gridlines.
The gridlines are static–that is, they don’t move–but they’re very useful for lining things up in the frame. You can enable them on the same page:
Settings (the toolbox icon) > Page 7/11: Display/Auto Review1 > Grid Line
They’re turned off by default, but you can choose from markings dividing the frame into thirds, a square grid, or a square grid and diagonals; I usually use the last one.