Introduction to VR lenses
The world of Virtual Reality (VR) is continually evolving, and one of the key components that significantly impacts the user experience is the type of headset lens. As VR enthusiasts seek the most immersive and visually stunning experiences, the debate over the best type of VR headset lens has been a topic of discussion. In this blog post, we’ll explore the various types of headset lenses and delve into what makes a lens stand out in terms of clarity, field of view, and overall visual fidelity.
1. Fresnel Lenses: The Pioneers of VR Optics
Fresnel lenses have become a staple in many headsets due to their ability to optimize immersion while addressing key challenges. Originally developed for applications like lighthouses, Fresnel lenses employ concentric grooves on their surface, allowing for efficient light bending and focusing. This design reduces the overall weight and thickness of the lens, a crucial factor in the comfort of headsets worn for extended periods.
One of the primary advantages of Fresnel lenses in VR is their ability to minimize the “screen-door effect.” This effect occurs when the visible lines between pixels create a grid-like pattern that can detract from the immersive quality of the VR experience. Fresnel lenses, by design, help mitigate this issue, providing users with a smoother and more visually appealing display.
However, Fresnel lenses are not without their challenges. One common concern is the presence of “god rays,” which are unwanted visual artifacts that appear as streaks of light in high-contrast scenes. This phenomenon can affect the overall clarity of the VR experience, particularly in scenes with bright elements against a dark background.
2. Pancake Lenses: Striving for Clarity
In VR headsets, pancake lens is just a bunch of lens elements and film layers tightly packed together, using the interaction between the film layers to reflect over and over between the layers to make the light in a straight path.
However, this kind of folded optical path has a big downside, the efficiency for light utilization will drop heavily, and it is difficult if not impossible to create an image without ghosting. Because only 10-20% of light will pass through the layers
If we take an LCD screen and pair it with pancake lenses we can achieve about 20% of light utilization. Better than OLED but still lacking with the potential of these lenses. Now if we take an OLED screen and pair it with pancake lenses we can only utilize about 10% of the light currently which makes it very hard for astonishing visuals.
The lightweight and sleek look and feel of the headsets using pancake lens do not outweigh the negative consequences in my opinion. The lost light returning to the human eye after poorly affecting the clarity of vision and creating a ghost image. Due to that it is generally not used in high-end units.
3. Aspheric Lenses: Striving for Clarity
Aspheric lenses aim to address some of the issues associated with Fresnel lenses, particularly in terms of clarity. These lenses have a single, smoothly curved surface, reducing the occurrence of god rays and enhancing overall image sharpness. The design of aspheric lenses allows for a more natural and distortion-free visual experience.
The improved clarity comes at the cost of slightly increased weight and thickness compared to Fresnel lenses. However, for users who prioritize visual fidelity and are willing to compromise on some aspects of form factor, aspheric lenses can offer a more visually appealing VR experience.
Glass aspheric lenses are a top pick for quality headsets in Virtual Reality. They have a very high PPD capability although it usually will require a heavier and bulkier headset. This is one of the few lenses that are HDR compatible due to high brightness from its 99% light passthrough. This is the choice for high fidelity image quality when weight is not an issue.
4. Hybrid Lenses: Striking a Balance
Hybrid lenses aim to strike a balance between the advantages and disadvantages of both Fresnel and aspheric lenses. By combining elements of both technologies, hybrid lenses seek to provide a compromise that delivers good clarity while minimizing the drawbacks associated with god rays and weight.
This approach is seen in some modern headsets that aim to offer a versatile visual experience suitable for a wide range of applications, from gaming to virtual tourism. Hybrid lenses showcase advancements in lens technology that cater to the diverse needs of VR users.
5. Varifocal Lenses: A Focus on Realism
Varifocal lenses represent a significant leap forward in VR optics, addressing a fundamental challenge – the accommodation-convergence mismatch. In the real world, our eyes adjust focus based on the distance of the objects we are looking at. Traditional VR lenses, however, have a fixed focus, leading to discomfort and reduced realism.
Varifocal lenses mimic the natural focusing mechanism of the human eye, allowing users to perceive objects at different depths more realistically. This innovation is particularly beneficial for applications such as virtual tourism, where users can inspect details up close, or for reading virtual text without the need for additional adjustments.
6. Customizable Prescription Lenses: Personalizing the VR Experience
As VR continues to gain popularity, manufacturers are recognizing the need for personalized experiences. Customizable prescription lenses allow users with vision impairments to enjoy VR without the need for glasses. These lenses can be tailored to an individual’s prescription, eliminating the discomfort of wearing glasses inside a headset.
This development is a game-changer for users who wear glasses, as it enhances comfort and eliminates the need for additional accessories. It also contributes to a more inclusive VR experience, catering to a broader audience with varying visual needs.
Conclusion
The choice of the best type of VR headset lens depends on individual preferences and priorities. Fresnel lenses, with their history in Virtual Reality, offer a lightweight and compact design but come with potential drawbacks. Aspheric lenses prioritize clarity, while hybrid lenses seek a balance between different factors. Varifocal lenses represent a step towards more realistic visual experiences, and customizable prescription lenses cater to users with specific vision requirements.
As technology continues to advance, we can expect further innovations in lens technology, pushing the boundaries of what is possible in terms of visual fidelity and user comfort. Ultimately, the best type of VR headset lens is subjective and depends on the user’s preferences, intended use, and willingness to prioritize certain aspects of the visual experience over others. As the VR industry evolves, users can anticipate even more choices and advancements in lens technology, making virtual experiences more captivating and accessible than ever before.
For our Arena at Mad Onyx VR we are implementing the Fresnel lenses, we believe it gives the users the best experience for the games we offer.