Camera care and travel: keeping the kit working, and getting it there

Cameras are more robust than their owners believe, and less robust in one place than their owners realise. Bodies survive rain, cold and years of being dropped into bags. What does not survive is a coated front element rubbed with a dry shirt and a grain of sand, or a sensor filter dragged across by an improvised swab.

Most of what worries people is cosmetic. Dust inside a zoom is normal and almost never visible, and specks on the front element are so far outside the plane of focus that they scatter a negligible amount of light. Sensor dust is the one that matters: it sits where the image is formed and shows as soft grey blobs at small apertures.

Front elements carry anti-reflective coatings a few hundred nanometres thick. They are hard, but not harder than the quartz sand that beach grit is made of. Every scratch comes from dragging a particle across the glass, so the technique is about removing particles before anything touches the surface.

1. Blow first. A hand blower moves the loose grit off. Never use canned air: it comes out cold enough to stress coatings and can spit propellant onto the glass.
2. Brush next, with a clean lens brush, in one direction rather than scrubbing. If the brush has touched your fingers it is now an oil applicator, so keep it capped.
3. Only then go damp. A drop of lens fluid on the cloth, never onto the lens where it runs into the barrel, wiped from the centre outwards in a spiral and dried with a clean part.
4. Wash the cloths regularly, without fabric conditioner, and retire any that have been on the floor. A dirty cloth is the commonest cause of a scratched lens.

Two things not to do. Do not breathe on the glass and rub, because the rubbing is the dangerous part. And do not clean a lens that does not need it: the rear element and the contacts matter more than the front, and both want air and a dry cloth only.

What people call the sensor is a stack of filters bonded over it, floating on a movable platform if the body is stabilised. You cannot touch the silicon. You can very easily scratch the filter on top of it, and the repair is a replacement assembly fitted at a service centre.

Find the dust first. Set f/16, focus manually at infinity, and photograph a blank wall or an even sky, moving the camera slightly so the wall blurs out. Raise the contrast hard. Dust shows as dark blobs in fixed positions.

1. 1

   Run the built-in cleaning cycle

   Almost every mirrorless body vibrates the filter stack at startup or on demand. Run it two or three times and re-shoot the test frame. It clears a good proportion of dust and cannot damage anything.

2. 2

   Blow it out, camera facing down

   Use the manual sensor cleaning menu item, which locks the mechanism in position, and hold the body with the mount pointing at the floor so dislodged dust falls out. Keep the blower tip outside the mount throat, never inside it.

3. 3

   Stop before the shutter

   Never let anything touch the shutter curtain. Some bodies close the shutter over the sensor at power-off and others do not, so you may be looking at blades a few hundredths of a millimetre thick. A bent blade is a workshop job and it happens instantly.

4. 4

   Decide honestly about wet cleaning

   If air has not cleared it, the dust is stuck, and stuck dust needs a swab and solvent. This is the point where a mistake gets expensive. If you are not confident, stop here and book a service centre clean.

5. 5

   If you do it yourself, do it properly once

   Swabs made for your exact sensor width, two or three drops of the matching fluid and no more, one steady pass in each direction with light even pressure, then throw the swab away. Never re-use one, never improvise with cotton buds or tissue, and never do it in a dusty room.

Condensation forms on any surface colder than the dew point of the air around it. Carry a camera from an air-conditioned room into tropical humidity, or from a winter street into a warm cafe, and water appears inside the lens as well as on it. Inside is the problem: it takes hours to clear, and repeated cycles encourage fungus and corrode contacts.

The fix is to let the kit warm up slowly in dry air, and the cheapest way to get dry air is to bring your own. Before leaving the cold place, seal the camera and lenses in a large freezer bag, squeeze the air out, and let the bag reach room temperature - twenty minutes for a small difference, an hour or more after a winter morning - before opening it. The condensation then forms on the outside of the bag, which is where you want it.

• Batteries lose capacity in the cold. Carry spares in an inside pocket and rotate them; a battery that has died at minus five often recovers once warm.
• Silica gel sachets in the bag cost nothing and are worth having in humid climates. Dry them in a low oven occasionally and they keep working.
• If a lens does fog internally, leave it somewhere warm and dry with the caps off for a day. Do not put it anywhere hot.

Weather sealing means gaskets at the seams, doors and controls, designed for rain, spray and dust. It is not a waterproof rating: most makers of interchangeable-lens cameras publish no IP figure, though rugged compacts and action cameras often do, describe the feature as resistance rather than proofing, and exclude water damage from the warranty. Read that combination for what it is.

• Sealing is a system. A sealed body with an unsealed lens is an unsealed camera, and the weak point is usually the mount. The same goes for an open card door or port cover.
• Gaskets age. Rubber hardens and compresses, so a ten-year-old sealed body is not sealed to the standard it left the factory with.
• Salt and sand are worse than water. Salt corrodes contacts and seizes zoom mechanisms; sand grinds. Wipe a sealed body with a barely damp cloth after a day by the sea.
• Sealing does not protect the front element, which is the part rain lands on. A lens hood keeps most of it off and is also the cheapest impact protection you can fit.

Treat sealing as one filter among several when buying rather than as a guarantee - how to choose a camera puts it against the rest. A cheap rain cover does more for a wet day than a sealing specification does.

One airline rule is not optional: spare lithium batteries travel in the cabin, never in checked baggage. That covers every loose camera battery and every power bank. Protect the terminals, with the supplied caps or a small bag each, so nothing metal can bridge them. Batteries fitted inside a camera in the hold are usually permitted, but the rules vary by airline and by route, so check yours before you fly — carrying the camera with you avoids the question entirely.

• Two spare batteries per body is the useful number. Mirrorless bodies run an electronic viewfinder all day, video drains faster still, and cold takes a chunk out of everything.
• Prefer two or three medium cards to one large one. A card failure then costs part of a trip rather than all of it. Format them in the camera that will use them.
• Back up every evening to something that is not the camera bag. Two copies in the same bag is one copy.
• A body that charges over USB can share the phone charger and a power bank, which is one less thing to pack.

This is the list for the three-lens kit in your first three lenses , and it fits a small daypack. Everything on it either takes photographs or stops the things that take photographs from failing.

Two things before any trip: shoot the f/16 dust test at home, where a service centre is still an option, and set the custom modes using the starting points in exposure basics . If you are still deciding what to take, focal length and framing works out which lens stays behind, and the camera finder narrows the bodies.