Don't stick this on your smartphone.

Cheap plastic screen protectors noticeably degrade camera quality. Photo: Lei Technology .

After discovering scratches on the camera lens of his old phone while preparing to resell it, user Xiao Lei decided to buy two lens protectors for 17 yuan (approximately 65,000 VND) to use on his new phone. However, he is now skeptical about the image quality after using the new protectors.

To test it, Xiao Lei directly compared two Xiaomi 17 Ultra phones, one without a screen protector and one with one. The results surprised him.

When shooting outdoors during the day, the difference is almost imperceptible on the phone screen. But when viewing the photos on a computer, the difference becomes immediately apparent. Photos from a phone without a screen protector have sharp, clear lines across the entire frame. Meanwhile, photos from a phone with a plastic screen protector are noticeably blurry at the edges, as if a layer of grease has been applied to the lens or a blurring filter has been added.

The next issue is chromatic aberration. In backlit photos, the camera without a protective film doesn't minimize color bleeding at the edges of bright areas. Cameras with a protective film show distinct purple and green fringing at the boundaries between bright areas. This is because the cheap plastic film has an uneven refractive index, scattering light and disrupting the optical system that the manufacturer has fine-tuned.

Night photography is even worse. When the sensor is partially obscured by a sticker, the night photography algorithm is disrupted. The image is not only darker, but the entire picture is severely blurry due to multiple light refractions between the sticker and the lens glass. This effect is similar to a thick layer of fog. High-end camera phones costing 7,000-8,000 RMB ( US$ 1,015-1,160) immediately reduce night photography performance to that of budget phones.

The protective layer for the camera module on smartphones is good enough and can be easily replaced if scratched. Photo: Lei Technology .

The reason lens protectors are more harmful than screen protectors is because camera lenses are highly sensitive to optics. Cheap plastic films lack an anti-reflective coating, causing light to be reflected and refracted multiple times before reaching the lens. The small gap between the protector and the glass acts like a "reflecting mirror" under strong light.

Many people use screen protectors because they fear the high cost of repairs if their lens gets scratched. In reality, in most cases, they only need to replace the outer protective glass, not the entire camera assembly. The cost at an authorized service center is only 70-200 RMB (10-29 USD ) depending on the brand, and you can even replace it yourself for just over 20 RMB ( 3 USD ).

Source: https://znews.vn/su-that-bat-ngo-ve-mieng-dan-cuong-luc-gia-re-post1640738.html