Monday 10 September 2018

dslr - Can a camera be affected by fungus?


I have heard lenses are pretty much vulnerable to fungus. That's why I protect my lens with silica gel. Can a DSLR camera also be affected by fungus? Should I protect them with silica gel, too?



Answer



Cameras can be affected by fungus, but in real world usage they usually aren't as vulnerable as lenses. There are a few reasons for this.



  • Most lenses that have a fungus issue have been stored for long periods in dark environments without being used. It usually takes months or even years for the fungus to become a significant problem.

  • There are more of us with more lenses than cameras than there are who have more cameras than lenses. This means we almost always use our "main" camera every time we shoot. But we may only use a few or even one of our many lenses for a particular shoot. Thus, we tend to leave lenses stored for longer periods than we leave cameras stored.


  • We usually keep lenses for much longer than we keep DSLRs. The life spans of lenses, especially good ones, are usually measured in decades. The life spans of DSLRs are usually measured in years. We either wear out the shutter or replace it with a newer, improved model much sooner than we replace our lenses.

  • The only part of a camera body where fungus affects optical quality is the imaging sensor and the stack of filters directly above it. I suppose it is possible it could also affect the optical path to the PDAF sensor which could deteriorate AF performance, or the optical path to the light meter which might affect metering, but I've never seen or heard of that actually happening. For DSLRs which have mechanical shutters, the shutter curtains are usually protecting the sensor stack from contact with dust and moisture laden air. Regular cleaning with a quality bulb blower should remove most dust before it has a chance to get to the sensor.

  • If we do get moisture and dust on the sensor stack, it is much easier to clean than the interior surfaces of a lens. It takes a while for fungi to do permanent damage to glass surfaces. If removed quickly, there is usually no permanent damage from fungus.

  • The interior of lenses tend to be exposed to more dust and moisture, the two ingredients that feed fungi, than do the interiors of camera bodies during normal usage. This is especially true of zoom lenses that change volumetrically as you zoom and, to a lesser extent, lenses that change volume as the focusing mechanism moves the front of the lens in and out. Lenses with internal zoom and/or internal focus aren't constantly pumping air in and out the way lenses that change their volume as they are used do. If you don't change your lenses very often, then almost everything that reaches the inside of your camera came in through the lens. This means there is probably more of whatever it is in the lens than in the camera body.


If you are storing your camera and lenses together in the same place then any protection you provide to your lenses by using drying agents will also protect your camera. I wouldn't recommend actually placing silica packets inside either your camera or your lenses. That could lead to more dust inside them from the material used to wrap the silica!


If you store them separately there's certainly no harm and might be some benefit to keeping a few silica packets in the space where your cameras are stored just as you do with your lenses. Exposing both to UV light, such as from the sun, is also a good way to inhibit the growth of fungus. (Yet another argument why you should normally leave the UV filter off the front of your lens unless you are shooting in an environment that really requires it.) But regular cleaning with a good bulb blower that filters the air it blows into your camera should be enough to protect your body if you are using it often.


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