When shopping for a camera lens, you might have encountered one with an “Asph” marking. You probably wonder what makes it different from the standard spherical lens. To help you with your purchasing decision, we will thoroughly cover aspherical lenses below.
An aspheric lens is a camera lens without a regular spherical surface. Instead, it features an aspheric or non-spherical shape. This lens structure can correct various aberrations that ruin the image quality.
However, an aspheric lens offers more benefits, which we will show below. This article will also answer “what is an aspheric lens?” and more questions regarding this lens type.
What Is an Aspherical Lens?
An aspheric or aspherical lens describes a camera lens that has a non-spherical shape. Unlike a regular spherical lens, it does not have a constant curvature across its entire surface. Instead, the curves change to help direct the light to the same focus point.
An aspheric lens can help correct all kinds of optical aberrations. It enables you to capture higher-quality images.
Aspherical lenses usually use glass, plastic, and silicone. These materials can reduce the weight and thickness of the lens while still providing excellent optical performance.
What Does Aspherical Mean?
Aspherical means not spherical. It lacks a perfectly round or symmetrical shape.
In photography, aspheric lenses offer an aspheric surface that is not part of a cylinder or sphere. They can correct spherical aberration and prevent ruining the image quality.
How Do Aspheric Lenses Work?
An aspherical lens can correct various aberrations by having a non-spherical lens surface. The complex shape of the glass elements allows light rays to converge at the same focus point. This way, the image sensor captures a photo without distortions and blurring at the edges.
Traditional lenses with spherical elements are less likely to reduce optical aberrations. That is because the round lens shape cannot guide light rays from different distances to meet at a single point. It can lead to spherical aberration and blurry edges of the frame. For these reasons, some photographers shoot using narrower apertures to prevent these issues and field curvature.
What is Spherical Aberration?
To fully understand aspherical lenses, you must know about spherical aberration and how it works.
Spherical aberration is one type of optical aberration (often considered a defect) in an image. Aberrations happen when light rays that pass through the lens or mirror do not meet at a single point of focus. This can ultimately lead to a blurred or distorted photo, which is especially noticeable at the edges.
The uneven distribution of light is a result of conventional spherical lenses. Since they have a constant curvature, they are unable to direct light coming from different directions properly.
Fortunately, as previously mentioned, aspherical lenses with a non-uniform shape can minimize various optical aberrations.
What Are the Applications of an Aspherical Camera Lens?
An aspheric lens has a wide range of applications.
This type of lens is primarily used to minimize or remove optical imperfections. It can correct aberrations by directing light into a single focal point.
Another use of an aspherical camera lens is to eliminate field curvature. It enables you to use wide-angle lenses without worrying about getting blurry images on the edges.
Finally, aspherical lenses are not exclusive to cameras. They are essential in contact lenses, eyeglasses, telescopes, and even missile-guidance systems. Aspheric eyeglass lenses, in particular, can combat astigmatism.
What Are the Advantages of Aspheric Lenses?
The main benefit of using aspheric lenses is improved image quality. These lenses minimize various optical aberrations to give you clearer and sharper photos.
An aspherical lens also produces more colorful images with better contrast.
There is also greater flexibility when it comes to design. Since it does not have to follow a strict circular shape, it helps you achieve your desired optical properties.
Finally, an aspherical lens also tends to be more compact and lightweight than its spherical counterparts. It is easier to handle and use, especially ideal during traveling.
What Are the Disadvantages of Aspheric Lenses?
Now that you know the advantages of aspheric lenses, you may feel tempted to buy one immediately. However, these kinds of lenses still have a few downsides.
First, they are more complex to make than spherical lenses. Due to this complicated production, they tend to be more expensive.
Another disadvantage of an aspherical lens is its susceptibility to flare and ghosting. So while it can eliminate aberrations, it can affect image contrast and quality.
Plus, aspheric lenses are not as widely available as spherical lenses. Hence, it can be challenging to find the right lens for your particular application or budget.
Are Aspheric Camera Lenses Better?
It depends on your specific needs and preferences. However, we believe aspheric lenses are many spherical lenses.
Aspherical camera lenses effectively eliminate unwanted aberrations and distortions in the frame.
They also help you capture sharper images with better contrast and color reproduction.
Finally, the aspheric glass elements make the overall lens construction lighter. They are suitable for travel photographers and others who are always on the go.
How Do You Know if a Lens Is Aspheric?
Some manufacturers include the “Asph” marking on the lens barrel to indicate the item has aspherical glass elements.
However, most camera brands do not have this designation. Instead, you have to check the individual glass elements of the lens to figure out if it is aspheric or not.
Are Aspheric Lenses Expensive?
Yes, aspheric lenses are more expensive than traditional lenses. Its high price tag is due to its complex design and construction.
Fortunately, technology continues to improve photography. You can now buy an aspherical lens for a reasonable price.
Remember to check the material of the lens before purchasing. Some models are cheap, but these plastic aspheric lenses are easy to break.
Conclusion
Spherical aberration and distortion are common problems when shooting wide. Fortunately, a special lens called an aspherical lens can help you achieve sharp photos.
An aspheric lens has a non-spherical shape. It can correct various optical aberrations to ensure higher image quality. It also offers other benefits, as mentioned in the section above.
Do you have more questions about aspheric lenses? Feel free to drop by our contact page to send your queries.
