Fungus cleaning from a Nikon superzoom

Question

Happened to be a proud owner of Nikon Coolpix P600 till I discovered that ugly fungus on its lens! Contacted the Nikon India service centre at Kolkata and they said that there is no option of cleaning the lens off fungus. The complete lens assembly is to be changed!!

Is it so? If yes, this could be a deal breaker for people aspiring to buy this camera. I spent Rs.20 K for this camera here and the lens assy is worth almost Rs.10 K! In this part of the world fungi can be spotted commonly on lenses.

Is it true for all other similar superzooms?

Bird watching using Auto mode in AF selected fails to focus especially when a dark colour bird sits inside a dark leafy bush. The focus hunts and the subject comes in sharp focus in one instance and blurs away in the next, making it almost impossible to get a sharp image.

The battery icon shows remaining charge pictorially and is not truly indicative of the actual juice remaining. On a tour, I found almost 30% charge remaining (as the icon shows it) and the camera said " battery exhausted" totally unexpectedly. I was saved to have a standby Sony Hx100V.

I must say the camera produces excellent results when in focus.

Answer 1

The problem of fungus is not specific to a single model or brand of camera. It will happen to lenses or cameras regardless of whether it's Nikon or bridge or a dSLR lens. Whatever camera you buy, if you're living in a warm humid environment, will be vulnerable to it, and yes, fungus damage can easily total a camera let alone cost more than a repair. Fungus waste products are often highly acidic. This acid can etch its way past coatings and into the glass. Repairing fungus damage may not be a simple matter of cleaning the lens, but also having to polish and recoat it, which could change the geometry of the lens enough to affect optical performance. So you'd probably be better off replacing the entire assembly, anyway.

The easiest way to guard against fungus is to make the lens inhospitable for fungus growth. Fungus typically requires heat, moisture, and darkness. If you remove humidity by using a drybox of some kind to store the camera, that's probably the easiest way to discourage fungus from happening in your camera. A simple air-tight container with some kind of dry desiccant (silica gel, rice, etc.) is probably sufficient, although if you're super-paranoid you could build or buy a dry box that lets you control humidity.

The issue with autofocus is not fungus-related, and again, isn't camera-specific. It has to do with how autofocus lock is typically achieved in digital cameras that only have the main image sensor array. The technique used is called "contrast detection"--the focus of the lens is racked in and out until the maximum contrast across values on the sensor is detected. A dark subject against a dark background in low light doesn't offer a lot of contrast to detect. Your AF system will work best when aiming for an area of high contrast (where white meets black), preferably with a sharp transition/edge between the two (e.g., print on a sign in good light). The autofocus hunting that happens with low light autofocus is typical on most digital cameras--even those that can perform phase detection as well as contrast detection.

See also: How does autofocus work?

Answer 2

The problem with your Nikon Coolpix P600 or any similar camera is that the amount of labor involved to disassemble (so it could be cleaned) and then reassemble the lens assembly would cost more than the camera is worth. And since fungus sometimes causes permanent damage to the surface of lens elements it might still be an exercise in futility. It is cheaper to just replace the entire lens assembly because the replacement is likely produced in the same facility as the original part in your camera, and benefits from the economy of scale (and likely heavy automation) of assembling them in large quantities.