OptoFidelity VR Multimeter

OptoFidelity VR Multimeter
Basic Info
VR/AR	Virtual reality, Augmented reality
Developer	OptoFidelity
Manufacturer	OptoFidelity
Versions	Display VR (display level testing of mobile phones or display modules); Desktop VR (complete HMD testing of tethered or untethered headsets)
Audio
Camera	ADNS3080 image sensor, 30 x 30 pixel frames
Device
Sensors	RGB sensor for display synchronization; shaft encoder for rotational position

OptoFidelity VR Multimeter is an end-to-end, optical test instrument for measuring VR performance KPIs such as motion-to-photon, pixel persistence and frame update frequency. It was made by the test automation company OptoFidelity for testing head-mounted displays (HMDs) and smartphone-based VR displays.

The instrument turns a headset on a rotary stage, films the headset's display with a camera and compares the motion of the displayed content with the measured physical motion. Because it observes the display from the outside rather than reading timing data from the software, it captures the full delay from physical movement to light on the screen, including the delay added by the tracking sensors. The original design measured motion-to-photon latency in one degree of freedom.

In 2017 Futuremark paired the VR Multimeter HMD solution with its VRMark benchmark in a VR latency testing platform shown at Mobile World Congress and the Game Developers Conference. OptoFidelity later renamed the product BUDDY-1 and developed the BUDDY-3 tester for measuring head tracking in three rotational degrees of freedom.

Reviewed 27 September 2026. Checked history, design, measurement specs and tables against the Koskinen presentation, Kapanen 2018 thesis, Futuremark/UL 2017 announcements, PC Perspective and OptoFidelity 2018-2019 posts and current BUDDY page. About review dates.

History

Sources give different launch years. A 2018 master's thesis by Sakari Kapanen, written for OptoFidelity, states that the company launched the VR Multimeter, its first VR testing solution, in 2016. A January 2019 OptoFidelity blog post gives 2017, saying that its HMD user experience testing started that year "when OptoFidelity's first offering BUDDY-1, previously known as VR Multimeter was launched."

On 22 February 2017, Futuremark announced that it had partnered with OptoFidelity on a VR latency testing platform. The platform combined VRMark with OptoFidelity's VR Multimeter HMD and was displayed at Mobile World Congress (27 February to 2 March 2017, on OptoFidelity's stand 5C43 in Hall 5) and at GDC (1 to 3 March 2017, on Futuremark's stand 142). PC Perspective described the arrangement as Futuremark partnering with OptoFidelity "to produce VR Multimeter HMD hardware based testing". Futuremark said the platform worked with PCs and mobile devices and could be applied to both VR and AR systems.

In a presentation on the product, OptoFidelity co-founder Tapio Koskinen described the aim as an affordable measurement solution that could sit on a designer's table, support continuous quality assurance of VR performance and be used without a Ph.D. degree, in place of a complex laboratory setup.

An OptoFidelity technology update in August 2018 said the VR Multimeter had been upgraded with autofocus for different HMDs and motion blur analysis, and that the solution supported most AR and VR HMDs on the market.

Later testers

The one-degree-of-freedom design had limits. According to Kapanen's thesis, its ADNS3080 image sensor could not precisely trigger the exposure of a frame, captured only 30 x 30 pixel frames at a maximum image transfer speed of 2 MHz, was poorly suited to synchronizing with low-persistence screens, and had been marked obsolete by its manufacturer. OptoFidelity therefore designed a new tester with a robot able to replicate human-like head motion in six degrees of freedom and a new camera synchronized to the display refresh, sharing a common code base with the Video Multimeter. The work was done in co-operation with the University of Jyväskylä, Department of Physics.

By January 2019 OptoFidelity referred to the original instrument as BUDDY-1, which it described as "a solution for benchmarking the motion-to-photon latency with one degree of freedom" and "a good work horse for basic motion-to-photon latency measurement e.g. to catch some fatal performance regressions." The newer BUDDY-3 measures head tracking accuracy in three rotational degrees of freedom using a sphere of coded markers shown in the virtual scene. As of September 2026, OptoFidelity markets BUDDY as an end-to-end performance testing system for AR, VR and MR glasses tracking and latency, in 3 degrees of freedom and 6 degrees of freedom configurations.

Design

Koskinen's presentation lists two hardware options. Display VR is for display level testing of mobile phones or display modules, and Desktop VR is for complete HMD testing of tethered or untethered headsets. Futuremark likewise described two hardware designs, one for full HMD testing and one for mobile device VR testing, built with high-accuracy mechanics for precise motion control and repeatable tests.

At the core of the system is the OptoFidelity Video Multimeter, an embedded device for measuring video playback performance. On its own the Video Multimeter can measure frame rate and persistence from an HMD; its firmware was extended to cover motion-to-photon latency when the headset is rotated in one degree of freedom. In the VR Multimeter test hardware the HMD is mounted on a rotary stage. A custom target pattern is shown on the HMD while it rotates, a camera tracks the optical flow of the pattern, and a shaft encoder gives an absolute reference of the rotational position. The software fits the encoder curve and the optical flow curve by finding the temporal shift that minimizes the difference between their shapes, and that shift is the motion-to-photon latency. The Video Multimeter samples an RGB sensor for synchronization, triggers image readout and collects data from the image sensor and the shaft encoder, which share one Serial Peripheral Interface bus.

According to the presentation, the system could be updated through firmware and upgradeable sensor modules, used patented technology to adapt to any display type, and supported full test automation through an API. Test content was available as an Android application and as a test image, with a Unity application and 360-degree panoramic photos and videos listed as backlog items. Futuremark said test sequences could be fully automated for continuous integration testing.

Measurements

The presentation defines motion-to-photon latency as the time needed for an HMD movement to be fully perceived on the VR display, typically below 20 ms. It argues that application-to-photon latency, often used instead, is an intrusive method that misses the delay caused by the tracker or gyroscope, and that the VR Multimeter measures the "true, end-user perceived Motion-to-Photon latency" by using accurate reference measurements of the HMD movements. The same presentation gives the pixel persistence formula as "PP msec = Duty cycle % / Content fps * 10" and states that too long a persistence causes motion blur while too short a persistence may affect brightness and contrast.

Futuremark listed the following among the key VR performance indicators that the joint platform measured end to end:

Indicator	Notes
Motion-to-photon latency	End-to-end, from physical headset motion to display update
Pixel persistence	Time the display uses to show the content pixels
Frame jerkiness and jitter
Dropped and duplicated frames
Left versus right eye frame delay
Audio and video synchronization
Motion-to-audio latency

The presentation gave these measurement specifications:

Parameter	Value
Primary probing frequency	100 kHz
Persistence accuracy	+/- 0.05 ms
Motion-to-photon accuracy (listed as "MP2 Accuracy")	+/-1 ms
Maximum synchronized frame rate	120 fps
Degrees of freedom	1DOF, more DOF on request

Example result screens in the presentation show an average latency of 33.4 ms and a pixel persistence of 1.97 ms with a rise time of 0.39 ms and a fall time of 0.50 ms; the presentation does not name the device measured. It also listed two capabilities as planned for the second quarter of 2017: measuring LCD ghosting through motion picture response time (MPRT) factors, a task that it said typically required complex and expensive pursuit or TDI cameras, and capturing sequential frame information from AR devices such as HoloLens so that motion-to-photon latency and persistence of sequential frame projectors could be measured.

VRMark integration

In the Futuremark platform, a test case measured motion-to-photon latency in a 3D rendering scenario. The benchmark took full control of the VR pipeline to show how CPU and GPU performance affect VR applications, and analyzed each frame to separate the time spent in the 3D engine, the VR API and the GPU. Futuremark's announcement stated that "Low motion-to-photon latency (< 20ms) is necessary to create the feeling of presence".

Research use

Sakari Kapanen's 2018 master's thesis at the University of Jyväskylä, supervised by OptoFidelity CTO Kimmo Jokinen and Arttu Miettinen, describes the VR Multimeter and the development of the smart camera for a new six-degree-of-freedom tester. The thesis includes measurements with the robot and the HTC Vive headset. It reports display persistence values measured with the OptoFidelity Video Multimeter, the instrument at the core of the VR Multimeter:

Headset	Display technology (manufacturer data)	Measured persistence
HTC Vive	AMOLED	1.9 ms
PlayStation VR	OLED	2.5 ms
Acer AH101 (AH101-D8EY)	LCD	2.6 ms

The thesis compares the VR Multimeter with other latency testers. It describes a method by Zhao and Allison, which uses a pendulum, a potentiometer and a photodiode, as conceptually very similar to the optical flow method of the VR Multimeter. It says that the Oculus latency tester for the Oculus Rift Development Kit has no motion sensor and appears to measure only application-to-photon latency, and that Basemark's VRTrek also measures application-to-photon latency.

See also

• OptoFidelity
• Motion-to-photon latency
• Pixel persistence
• Low persistence
• VRMark
• Head tracking

External links

• Read more about the product line