Understanding Haze: Camera Lenses And Their Clarity

Haze on camera lenses can be caused by a variety of factors, including surface contaminants such as oil, grease, heavy dust, or fingerprints; fungus growth due to a combination of dust and moisture; and balsam separation, where the adhesive used to bond lens elements breaks down over time. Other potential causes include internal reflections, corrosion or fungus of the glass itself, and environmental factors such as air pollution or smoke. While haze can impact image quality, its effect on photos varies depending on the severity of the haze and the quality of the lens.

Surface contaminants

Haze on camera lenses can be caused by a variety of factors, including surface contaminants. Surface contaminants refer to any substance that comes into contact with the lens surface, leaving a residue or film that impairs the optical quality of the lens. This can include a range of substances, with varying levels of impact on the lens.

One of the most common surface contaminants is oil, which can come from fingerprints or natural oils in the environment. Grease is another substance that can cause haze, often left behind by technicians during the manufacturing or repair process. Heavy dust can also build up on lenses over time, especially in environments with high particulate matter in the air.

Other less common but equally detrimental surface contaminants include lubricants from the internal mechanics of the camera. This can vaporize and condense on lens surfaces, leaving a residue. Additionally, any liquid that gets inside the lens and evaporates can cause haze. This could be caused by something as simple as condensation from changes in temperature or humidity.

The impact of surface contaminants on image quality can vary. In some cases, the haze caused by these contaminants may be barely noticeable, while in other cases, it can lead to a significant loss of sharpness and contrast in images. It is important to note that even a small amount of haze can impact image quality when shooting into direct light, as the light reflects off the contaminants and causes flare.

The good news is that surface contaminants are often relatively easy to remove. A competent technician can usually disassemble and clean the lens, restoring it to its original condition. However, it is crucial to act quickly, as some contaminants, like fungus, can cause irreparable damage to lens coatings over time.

Fungus

Haze on camera lenses can be caused by fungus, which usually appears as 'spiderweb' patterns. It thrives in conditions of heat, moisture, and protection from UV light.

An alternative method is to expose the lens to direct sunlight or UV light, which will kill the fungus. However, this method does not physically remove the fungus, and it may regrow if the lens is not kept in a bright, dry location.

Balsam separation

Haze on a camera lens can be caused by a number of factors, one of which is balsam separation. This is when epoxied lens elements start to delaminate, or separate. The description was originally specific to Canada balsam, a turpentine made from balsam fir tree resin, but it also applies to modern lenses that use various epoxies.

• A decrease in contrast
• More flare and ghosting
• Softer corners and a loss of sharpness over the frame
• Focusing may become difficult
• "Dust spots" on images from remnants of the adhesive used to bond the lens elements

If the lens elements completely separate, the lens will be unusable. Repairing balsam separation can be difficult and may not be worth the cost, especially for common lenses. However, it is possible to attempt a DIY repair by harvesting a replacement lens group from a donor lens or re-cementing the lens elements.

Lubricants

In addition to lubricants, other liquids can also find their way inside a lens and cause similar issues. For example, lenses purchased at flea markets may have been exposed to moisture, leading to condensation and residue on the glass.

The impact of lubricants on haze formation can vary depending on the type of haze. Smoky haze, which is more common, is caused by the diffusion of light by particles smaller than the wavelengths of light. This type of haze typically affects the entire image, reducing contrast and making blacks appear grey. On the other hand, oily haze is caused by condensation into tiny droplets that are larger than light wavelengths. This results in haloes around bright parts of the image, diverting light and creating more visible and annoying artefacts.

While lubricants can contribute to haze formation, it is important to note that they are not the only factor. Other causes of haze include surface contaminants (such as oil, grease, dust, or fingerprints), fungus growth, and balsam separation (where pine balsam used to bond lens elements dries and causes them to separate).

Corrosion

Haze on camera lenses can be caused by a variety of factors, including surface contaminants, fungus growth, balsam separation, and corrosion. Corrosion on camera lenses refers to the oxidation of the glass elements, resulting in tiny pits that affect the lens's optical quality. This issue is relatively rare and occurs when the glass is susceptible to corrosion and the protective coatings are insufficient.

To prevent corrosion, it is essential to maintain the camera lens properly. This includes regular cleaning, ensuring the lens is stored in a dry environment, and avoiding exposure to harsh chemicals or substances that may react with the glass elements. Additionally, using a lens filter can provide an extra layer of protection.

If corrosion does occur, it may be possible to mitigate its effects by cleaning the lens with specialised cleaning solutions or seeking professional repair services. However, in some cases, the damage caused by corrosion may be irreversible, requiring lens element replacement or other extensive repairs.

It is worth noting that corrosion is not the only cause of haze on camera lenses. Surface contaminants, such as oil, grease, heavy dust, or fingerprints, can also lead to haze. Fungus growth, resulting from a combination of dust and moisture, can cause spiderweb-like patterns and permanent damage to lens coatings. Additionally, balsam separation, where the adhesive between lens elements breaks down, can cause a rainbow pattern in the lens.

To summarise, corrosion is a rare but detrimental cause of haze on camera lenses. Proper maintenance and storage of lenses are crucial to prevent corrosion and other issues that may impact image quality.

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