Lens cleaning tools

© 2011 Stefan Lundberg

Top class lenses is a main factor behind high quality photography, in fact the lens plays a bigger roll than the actual body used. High quality lenses need some attention between photo sessions to keep on delivering a good results. It is also important to know what lens assessors to use together with each lens to optimize each different photo situation.

Many photographers use filters for protection, but it is not that common to use filters to shorten the closest focus distance, compensate for uneven scene light, change light temperature etc. For really good results it is important to know which combinations that works and how to fix certain problems. A good photographer is prepared for surprises and know how to work around problems.

Start using filters

For protection and to easy cleaning it is convenient to have some sort of filter on the camera all the time, this filter can be a clear glass filter or more common a UV filter (Even if no UV light need to be blocked in front of an digital camera, the UV blocking property adds no artifacts) It is important that the filter is of high quality since the filter affects the image. The most important parameter of a filter is the coating used to cancel reflections which enables a larger amount of the light to reach into the lens. Another important feature of a filter is the cleanability, how easy dust, dirt and water can be removed from the filter without scratching or removing the coating.

Example of a bad flare, from an uncoated plastic graduated neutral density filter

Normally it is a bad idea to stack many filter because the amount of possibly bad reflections increases for each glass element in the optical system. Filters does also affect the flares which in many high quality lenses are very low and may increase dramatically with a bad filter. Note that some plastic filters (still professional) are are almost impossible to use in a sunset scene with the sun in or close to the visible part of the image. I have attached a photo to this post with a really bad flare created by the external filter. In this case a graduated neutral density filer from Cokin that unfortunately render flares all over the place.

Lens hood

A lens hood is placed in front of the lens to improve the contrast in the image. The lens hood does this by blocking or shading unwanted light coming in into the lens from the scene. Example of this is direct sunlight that shines on the lens filter or front element on the lens. some small part of this light will scatter randomly and a fraction will hit the sensor in a bad spot. Only 1% of bad light will be visible in an normal image. If this extra light is spread evenly over the complete image it will be possible to remove in post (using the contrast/levels or similar slider) but if either the dynamic range is insufficient or the light is spread unevenly the image will suffer from difficult to fix contrast or flares problems.

Each lens has an optimal lens hood and the size of the hood is very different for each lens type, wide angle lenses has very small hoods and tele photo lenses very large. It is possible to use universal hoods from third party manufacturers but it is better to use the optimal hood provided by the lens manufacturer.

Lens and filter cleaning

Lenses and filers are cleaned in similar way, depending on the type of dirt on your glass surface either a clean dry viper or a solvent can be used. If the dirt is dry dust not attached to the surface a simple blow with a camera blower might be enough, this is the safest and best method. Do not use compressed air from a pressured can because the air may contain liquids and be to cold for your equipment. Do not you any air compressor or air pump not designed for this purpose, there is a small risk that the air contains oil or other bad content. If the dust does not come loose with plain air a clean viper can be used. Pay special attention to sand and other hard dust, it might destroy our sensitive surface. For really tough dust it is necessary to use a camera cleaner solvent that is of very high quality and does not contain anything that leave traces on the glass afterwards. Use optical cleaner sheets and small droplets of solvent to mechanically clean the surface. move the cleaner over the surface with small circles and a firm pressure. Only use the optical paper once and pay attention to grains of hard particles like sand dust.


© 2011 Stefan Lundberg

A new method to clean lenses and filters is by using a so called lens pen, which uses carbon to absorb fat from your fingers on optical surfaces. This method works very well and the results looks like the lens arrives direct form factory. No traces from the solvent along the edges where is is difficult to reach with the optical paper. The lenspen can easily be kept in your camera bag, it is small, has low weight and is allowed to carry on any aircraft through security and to bring to every country in the world independent of alcohol restrictions.

Lens adjustments

Now and then you lens might need to be adjusted, the far end focus may have shifted, some of the bearings may need to be tightened to avoid zoom or focus adjustment just by pointing the lens downwards. If the focus shift is small it might be possible to compensate for it with the new micro focus adjustments available in some camera bodies, otherwise, lens (and camera house) hast to be sent to a service center. Tighten the zoom ring is very easy on some models just slide the zoom rubber grip aside and use a small screwdriver.

Lens repair

It is possible to repair lenses at home but it is not recommended for most users since it requires some skill and some guts. Is you still what to try, read more here, Everything about Canon service manuals.

It is easy to clean out dust from easily accessed lens elements, just remove the fastenings and clean the glass like a filter. It is important to put the glass back facing in the same direction since most lenses have a front and back side. Always use proper tools when removing glass elements, a bad tool can easily scratch your element.

EF 70-200 with broken distance scale window

© 2011 Stefan Lundberg

Another easy fix is to replace worn out focus and zoom rubber rings, they come off very easy and the new one just slides in place. A broken window for the distance scale can sometimes be very easy to replace, just order a new, they are self-adhesive. Be care full when removing the old one, you do not want broken parts to en up inside the lens. If some piece of the glass is missing you need to check so that the missing part is not doing damage inside the lens. To check for lost part or screws inside a lens, a total diss assembly might be needed.

Internal filters

On some lenses (Usually high quality wide angle or long tele photo lenses) it is possible to add a little filter in the back of the lens or in an slide in slot on top of the lens. It is not that common to use this feature any more because the light compensation can be done digitally and even automatically by the camera. But in some cases when you know at every image for a session will be taken with colored light that requires compensation it might be a good idea to install a compensation filter already in the lens in order to save important dynamic range in the internal A/D converters. To do this you need small high quality gel filters than can be cut into correct size.

Lens storage

To avoid expensive damage to some of your photo equipment install some sort of easily accessible storage system, where unused lenses can be placed when they are not in the camera bag. It is very good if the storage is easily to keep dust free. This storage shall be in an dry environment with constant room temperature. Lenses does not like to be placed in the sun or stored bellow freezing point. A very good but expensive solution is to use multiple camera backpacks for all unused parts.

Lenses in the camera bag

Your camera bag shall always be ready for unspecified photography, that means your batteries full, memory card ready, and at least one universal 16-35, 24-70, 24-105, 70-200 or similar lens mounted on the camera body. Before each photo occasion the camera bag needs to be configured, that includes, lens selection and lens packing. Take good time and think over what lenses you really need to carry because they are heavy and requires space in your bag. Pack the camera bag together with care and move needed spacers and add missing stuffing to protect your lenses all the time.

It is not uncommon that the camera bag will suffer from vertical drops, general tough handling, ski accidents, bicycle crashes and more. Good protection between every part is everything.
Another common threat to your babies are water, an ordinary shower might destroy you stuff if you are unable to cover your bag properly. It is a good idea to buy camera bags that are all-weather (AW, that means that there is a protection cover available the can be deployed in rainy conditions.

Fully water protected bags are available but tend to be clumsy and difficult to get in and out, they are for use in really tough environment like in canoes and on the sea.

Water damages

Water damages can be divided into salt water damages and non salt water damages. If electronics is dropped in salt water you have to immediate take apart everything, and wash in clean water followed by careful drying. The salt will in very short time destroy all electronics and rendering it useless. Pool water is equally dangerous as salt water because the aggressive chloride that is used to keep germs away.

In case of clean water or rain water damages there is a larger chance that the equipment might be possible to rescue. The best way is to take everything in pieces, eventually some part need to be clean with tap water. When everything is opened up and clean, warm dry air can be used to vaporize water and remove moistener as long as the air does not destroys anything that can stand the heat. Optical elements will need additional cleaning afterwards. The most difficult part are small electronic motors and other electromechanical devices.

My last tip: Avoid water, moister, dust and sand near your camera equipment.

Snow on  the lens

Wide angle lenses are very sensitive to dirt on the lens due to the large depth of field.