How to choose a projector lens? Which is better, zoom or fixed focus?

How to choose a projector lens? Which is better, zoom or fixed focus?

"Friends who are familiar with projectors know that the lens, as an essential component of smart projectors, plays a crucial role in projecting and enlarging images, ultimately completing the projection process. The adjustment of the projection distance and the quality of image reproduction are closely related to the lens. So, what is the structure of the smart projector lens, and what are the advantages and disadvantages of lenses made from different materials? How can we select a projector based on the smart projector lens? Today, let's briefly delve into the related knowledge about projector lenses. Take out your notebooks and pay attention!

1.Lens Structure
The smart projector lens is actually composed of a lens barrel and multiple lens elements, forming a light channel with a wider top and a narrower bottom. Some may wonder why a projector lens needs so many pieces. In fact, different lens elements serve different purposes. Lens elements affect focal length, focusing range, and the image quality after focusing. Each lens element has a specific role, some for magnification, some for focusing range, and sometimes they need to compensate for each other to adjust chromatic aberration and improve image quality.

2.Lens Materials
Currently, projector lenses on the market mostly use glass lenses and resin lenses. Full glass lenses, as the name suggests, have lenses made entirely of glass. Their advantages include high hardness, strong wear resistance, long service life, and resistance to deformation under temperature changes. However, they come at a higher cost. You'll generally find that projectors with full glass lenses are priced above a thousand dollars, and smart projectors below a thousand dollars rarely have full glass lenses.

For projectors priced below a thousand dollars, most use a configuration of resin combined with glass. The advantages of this configuration include strong impact resistance, light weight, and, most importantly, higher light transmittance as resin lenses. The disadvantage is that the chemical stability is slightly weaker than full glass lenses. For example, the refractive index is weaker than that of full glass lenses, and in terms of image reproduction, it is not as high as full glass lenses. However, from a technological standpoint, the optimization of lenses in smart projectors has narrowed the gap in image reproduction quality between resin and full glass lenses, making it practically indistinguishable to the naked eye.

In summary, although both lens materials have their pros and cons, when choosing a home projector, it is recommended to consider your budget and acceptable standards. After all, full glass lenses priced above a thousand dollars are not something to be taken lightly. Moreover, with the current level of intelligence in smart projectors, some brands have achieved excellent focus compensation technology, including heat virtual focus sensing and microsecond-level compensation, coupled with fully automatic focusing technology, effectively addressing the differences in lenses.

3.Impact of Light Source on Lens
Let's also consider the impact of the light source on lens design, mainly in terms of changes in the aperture F-value. The aperture's basic function is to control the amount of light passing through, and the F-value indicates the size of the aperture (F-value = lens focal length / aperture diameter). A larger F-value means a smaller aperture and higher contrast. Depending on the requirements of different models, lens designs will vary, so it's not a matter of simply putting down the same focal length; adjustments need to be made based on the characteristics of different light sources.

4.Zoom Lens vs. Fixed Lens
Speaking of zoom and fixed lenses, many users may be confused. This is related to the concept of projection ratio. The smaller the projection ratio, the closer the projector can project a large-screen image. A zoom lens can adjust the projection ratio, while a fixed lens cannot. In general, projectors with optical zoom lenses are better than those with fixed lenses. Especially for small to medium-sized homes with a projection distance of less than 3 meters, it is recommended to consider optical zoom projection. Currently, the X5 is the projector with the highest cost performance in optical zoom, maintaining 1080P native full HD resolution without sacrificing image quality when adjusting the size.

That concludes this informative session. Do you now have a better understanding of the projector lens-related knowledge?"
Back to blog

Leave a comment

Please note, comments need to be approved before they are published.