You may have been attracted to EOS cameras by the reputation of their lenses. And it is true. EF lenses can give you outstanding images – but only if you look after them. If a lens is not in perfect condition, the quality of your photographs may suffer.

On a more mercenary note, a lens that has been well looked after will hold its value better than one that looks as if it has been heavily used and abused. Here are a few basic tips that will ensure that your valuable lenses are well protected. Much of what follows is common sense – but how many of the ideas do you actually put into practice?

Every new EF lens is supplied with two lens caps. Do you use them? The front cap should always be in place when the lens is not in use. Even if you have a screw-in filter attached, it’s a good idea to use the lens cap as well – a new cap is cheaper than a new filter.

Most lens caps will attach to the front of a filter in just the same way that they attached to the front of the lens. When is the lens not in use? You could argue that it is when you are not looking through the viewfinder or pressing the shutter release. It would certainly be good if you could clip the cap in place at these times. However, we need to be practical. If you are out on a sunny afternoon looking for photo opportunities, camera hanging from its neck strap, you probably do not need the lens cap on between pictures. It can be annoying to see a great shot, lift the camera to your eye, and then realise that the lens cap is still in place. If you are photographing wildlife, this could lose you a picture.

However, if there is rain in the air, or you are at risk of being splashed with water, then put the cap in place at all possible opportunities. Water evaporates, but it often leaves behind dissolved impurities that can mark the surface of a lens.

The second lens cap fits the rear of the lens. It should always be put in place the moment the lens is removed from the camera – no exceptions. This will protect the rear element from damage when you put the lens down. Just as important, it will help to keep the gold electrical contacts clean. These contacts are the only link between the lens and the camera. If they become dirty, all manner of things can happen – or fail to happen – when you try to take photographs.

For the same reason, it is important to fit the body cap to the front of the camera whenever there is no lens attached. Not only will this protect the gold electrical contacts on the camera side, but it will also prevent dust and dirt reaching the reflex mirror and the focusing screen. Lens and body caps are easily lost, but most of them are also relatively cheap to replace. Next time you need one, buy two and keep the spare in your gadget bag.

The glass used for making optical lenses is often much softer than other types of glass. Once marked, it is not easy to clean. Most lenses have a coating applied to the surface of the front element. The main purpose of this is to reduce the risk of flare, but it also provides a harder surface. However, the term ‘harder’ is relative, and it is still quite easy to damage the surface of the lens. Rain, dust, flying stones, foliage and fingers are among the potential dangers.

Fingers in particular are a risk. Your fingertips exude an acidic grease which can, over a period of time, eat into the surface of the lens. The result may not be very noticeable, but it can increase the effect of flare. For this reason, if you touch the surface of the lens with your fingers, you should polish it gently with a soft, dry cloth to wipe away the grease.

You can protect the surface of the lens from fingers and other perils by attaching a filter. This screws into the mount at the front of the lens, forming a virtually dustproof seal between the surface of the lens and the outside world. Any dust or damage is then sustained by the filter and not the lens. If the damage is beyond normal cleaning methods, it is far cheaper to replace the filter than the lens.

Canon produces a filter specifically for protection. The Canon Regular filter (previously known as a Protect filter) is made from perfectly clear optical glass that does not alter the light passing through it. Strictly speaking, it probably offers a little ultraviolet filtration, as this is a characteristic of all glass, but the effect is so small as to be insignificant.

Although the Regular filter is ideal in situations that require an accurate colour balance – studio photography or copy work, for instance – an Ultraviolet (UV) or Skylight filter can be just as good for protecting a lens. These block ultraviolet light that can cause a blue haze over distant landscapes. In addition, a Skylight filter has a pinkish tint that reduces the blue cast in shadow areas under blue skies. In most situations, however, an Ultraviolet or Skylight filter has no noticeable effect on your photographs.

Lens Hood

If you drop a lens – with or without a camera attached – there’s a good chance it will land on the exposed filter ring, denting it. Or, even worse, the front element of the lens may impact on a sharp stone. You can reduce the risk of dropping the camera by using a neck strap and always slipping it over your head whenever you pick the camera up.

You can’t attach a strap to most lenses, but you can reduce the risk of any damage by holding the lens close to a flat surface when you attach or remove it. Then, if the lens does slip out of your grasp, it will not have far to fall. Outdoors, you may have to crouch or kneel so that the camera is close to the ground as you attach or remove a lens. If the worst happens and your lens is launched into free fall, the risk of damage might be reduced if it is fitted with a lens hood. A hood protrudes from the front of the lens and may take the brunt of an impact. Canon produces hoods for most of its lenses.

Apart from protection, there is a good argument for using the correct hood all the time – it can help to reduce the risk of flare from the sun or other bright lights in front of the camera.

It’s all very well looking after your lens while it’s mounted on the camera, but it is equally at risk when off the camera – even when stored in a camera case or bag. The safest way to store a lens is in the correct hard case or pouch. This can then be placed inside your camera bag or case. Canon has discontinued most of its hard lens cases, but you may be able to find one secondhand. A range of pouches is still available, however, and one of these is a low-cost, lightweight means of protecting a lens.

If you don’t have a case or pouch to hand, a cheap but effective way to protect your lens is to wrap it in a clean, lint-free duster. This will reduce the risk of scratches and dents if the lens rolls around in a case and bangs into another lens, or the camera body.

Many gadget bags and camera cases allow you to move partitions around to provide snug, padded compartments for each item of equipment. This is a good alternative to a lens case or pouch. A coat or jacket pocket can also be a surprisingly safe place for a lens. A deep coat pocket (or even better, a padded packet in a photographer’s waistcoat) will cocoon a lens.

Whichever method you use to protect the lens, make sure you always fit the front and rear lens caps first.

Good camera bags

If you are travelling by car, the worst place for your camera bag is on the floor in front of the passenger seat. Here, the equipment will be subject to all the vibrations from the engine, and the shocks as you drive over bumps. Although lenses are surprisingly durable, it is possible for components to loosen or shift position.

Placing the bag on one of the seats will help to protect the equipment from vibrations, but is only safe if you carry the bag with you when you leave the car. A camera bag left in view after you have parked the car is asking for trouble. A thief can break the window, lift the bag and be away within seconds.

If you carry the camera bag in the boot of a car, it is a good idea to reduce vibrations by placing a folded blanket underneath

Some of the time, your lenses and camera will probably be kept at work or home. Keep the equipment in a bag or case so that it is shielded from daylight. Make sure the equipment is not near a central heating radiator, and avoid places that may be damp, or have damp air circulating.

The ideal location will have a constant temperature all year round – neither too hot nor too cold. Between about 5°C and 10°C is good.

Important tips

• If you use a Regular, Ultraviolet or Skylight filter as protection on a wideangle lens, do not add further filters. The mount of the front filter may intrude into the image area and cause vignetting.
• At all costs avoid touching lens elements with your fingers. Human sweat is greasy and acidic and will eat into the delicate multi-coating of the lens, leading to your fingerprints becoming indelibly imprinted onto the lens. This can lead to problems with flare and make the lens worth less on the secondhand market.
• Fingerprints and minor scratches may not be immediately apparent when looking at a lens, which can be a worry when buying secondhand. There is, however, a way to make any marks magically appear. Simply breathe on the lens’ elements and any flaws will show up as your breath condenses on the element. The moisture will disappear in a second or two, leaving the lens unaffected.
• Looking after your camera and lens as described will help to ensure that it holds they value. In addition, you will maximise the value of your equipment by keeping the original box, packaging and any paperwork that came with it. Even though most people don’t use the boxes for storage of the camera or lens, a classified advertisement with the words ‘mint and boxed’ is attractive to many buyers – perhaps implying that the equipment has not been used very much.