FAQs from Encore Camera

A scratch – You can feel when you gently run a fingernail across it. A scratch mark, if it is deep enough,  may affect image quality.

A cleaning mark or a hairline – It is only on the coating and cannot be felt when you run a fingernail across it. Unless it is extremely heavy, it will not refract light and won’t affect any image quality.

 A few tiny dust particles may be visible  when you look into the front of the lens in bright light source, like a bright halogen desk light.  Especially in older, larger zoom lenses, this is normal and won’t affect lens performance.  They are too close to the lens surface to record on the image. Consider that the dust will impede about 1/1000% of the total light travelling through your lens, and that the focal point of the lens is anywhere from 12 inches to 6 feet away from the lens. The net effect of these tiny dust particles is negligible on image production.   .

For instance, if you wear eyeglasses, just take them off and look closely at the lenses. You will probably see lots of micro dust, yet when placed directly in front of your eyes the view is clear. Same concept applies to a camera lens when attached to a camera.  If the lens elements are full of heavy dust particles or fibers, the Image quality may decrease accordingly.

Like micro dust, tiny black specks will not affect image quality, but larger black specks may affect image quality. If such specks are seen inside the lens elements, we describe the condition accordingly.

Lens fungus is a microbial growth on glass surfaces of camera lenses and other optical devices. It is literally a disease of lenses which is very common.  It takes a number of forms but the typical destructive growth pattern from microscopic spores growing in webbed mycelium patterns across an optical surface.  Fungus in a lens will eventually degrade the image as it tends to grow. But as the amount of degradation may be invisible to human eye, it may make the lens completely unusable by any standards.  In some cases this can be cleaned off and the lens restored, but often the metabolic products of the fungus etch the glass lens surface or coatings, or the growth may be on internal glass surfaces that cannot be reached for cleaning.

Lens haze comes from numerous sources – dust within a lens, great, or adhesive off-gassing, and even poor lens mechanics using super glue or other high-volatile glues.  Though no dust has gotten into from outside, as the cement has broken down particles of it have become lens haze. Or internal lubricants vaporize slowly and collect back on the glass. It gets worse with age, and worse when stored at higher temperature and humidity. Heavy haze may softens images drastically.   Amount of haze can be minimized once it is cleaned by a professional camera repair service in conjunction of CLA.

When you see oil present on the aperture blades, there is friction from the oil’s viscosity and this impedes the quick closing action during exposure. Normally people think oil is good for lubrication, but in this case, dry blades move faster. By the time the aperture has stopped down during exposure, the shutter action has long since completed, and every photo is overexposed from too much light entering the shutter plane.

A lens that has been subject to extreme heat can develop an oily aperture. Grease from the focus gear liquefies from the heat and works its way centrally over time into the aperture area where it wreaks havoc.
 

Oil can be cleaned or removed by a professional camera repair service. This repair can be combined with CLA.  Never leave your camera gear in a car in the summer sun as this is the most common cause of this issue.