Thursday, June 2, 2022

CLEANING YOUR LEICA LENSES



By Heinz Richter

Regardless of how careful we are, sooner or later our lenses need cleaning.  Opinions differ widely on what the best method to clean a lens is.  Subsequently there are quite a large number of products on the market, and virtually all of them claim that their method is better than anyone else’s.  What to do?

Regardless of which product or which method we use, the two important objectives are that the product and method does clean the lens properly, and that it can be done in a manner that does not harm the lens.  

It is often said that glass scratches easily.  That is correct.  But with modern lenses we actually do not clean the glass surface but rather the anti reflection coating on the lens.  This sometimes brings up some outlandish claims, like the coating is substantially more scratch resistant than just glass, therefore making it unnecessary to be overly careful.  As a matter of fact, at one camera store I overheard a sales clerk claiming that the lens coatings are almost impossible to scratch.  To my horror, he used a pencil with an eraser tip and vigorously rubbed it all over the surface of the lens.

One problem is that harmful ways to clean a lens don’t necessarily show up in visible scratches immediately.  These effects are accumulative, and prolonged use will eventually show up.  At that point the harm is done.  It is virtually irreversible.

The best approach is to touch the surface of your lens as little as possible.  If only some dust has settled on the lens, use a rubber blower to remove it.  That often is all that is necessary.  It is advisable, however, not to use so called canned air.  These items emit a rather powerful stream of “air” which inevitably will pick up small dust particles in the air and pound them into the lens surface.  This parallels the principle of sandblasting.  When full, these cans also have the tendency to emit so much of the material inside that it does not gasify before it reaches the lens.  In that case it will settle on the lens in a frozen state.  That obviously will be harmful and should be avoided.

 Typical blower bulb

Any dust that still clings to the lens can be removed with a soft lens cleaning brush.  Here too a lot of cheap, useless products can be found.  High quality lens cleaning brushes, in many cases, use camel hair or other similarly soft materials.  Any good lens cleaning brush should come with a protective casing to prevent the brush from picking up dirt while being stored.  It is also necessary to shake or blow off any accumulated dust and dirt from the brush, otherwise we end up simply moving dirt around on the lens.

 So called lipstick brush. It retracts and is protected by the cap

Unfortunately it will happen that we get a fingerprint or other smudges on the lens.  Blowers and brushes are of no help here, we need something in addition.  Several years ago, on a visit to Leica, I asked them about this.  I expected some complicated, overly technical approach.  To my surprise I was told to use lens cleaning tissue and lens cleaning fluid.  A bit of research on the internet revealed that this still holds true today.

But caution is definitely in order.  There are a lot of cheap products of this kind on the market.  Some of these are often used as promotional items.  Stay away from them.  Instead pay a bit more for a high quality lens cleaning tissue as is sold by Zeiss, for instance.  These should be soft and lint free.  The same goes for the cleaning fluid.  To use this system first remove any loose dirt and dust with a blower or brush,  Then use a sheet of the cleaning tissue and put a drop or two of the cleaning fluid on the tissue.  Never put it directly on the lens.  Most lenses have a front element with a convex surface.  Adding the cleaning fluid will most likely result in the fluid to run to the edge of the front lens element and potentially into the lens.  Moisture inside a lens is never a good thing.



Use the moistened lens tissue and gently rub the surface of the lens in a circular motion for just a few seconds, beginning in the center and working your way outward, removing any marks or smear.  If necessary use a second tissue and repeat.  Some lens cleaning fluid might leave a slight haze after drying.  The Kodak lens cleaning fluid used to do that.  This is not harmful. In such cases simply breathe on the lens and clean off the haze with another, clean piece of lens cleaning tissue.  As a matter of fact, breathing on the lens is often all you need to clean it.  The thin layer of moisture works as a lubricant.  Never use dry tissue on the lens.  This too can cause harm.

Instead of lens cleaning tissue, you can also use a microfiber cloth.  These are relatively new on the market.  They are made of extremely thin fibers that will actually reach underneath smudges and dirt on the lens and lift it off the surface.  Of course here too exist substantial quality differences.  Promotional items, like the ones you get with your eye glasses, are usually too coarse to be of any use.


One of the best microfiber cloths is the one offered by EDDYCAM.  It was especially developed for cleaning high quality lenses.  It offers high moisture absorption.  To achieve the extremely fine fibers used, the regular microfibers are split 16 times to render the extremely fine fibers used in the manufacture of this cloth.  The structure of  the surface is so dense that a square meter of the material weighs 180 grams.  Another advantage over similar microfiber cloths is that the EDDYCAM one comes in white.  This makes it much easier to see when the cloth is dirty to the point that it needs to be washed.   It even comes with an envelope in which you can leave the cloth at the end of its usability at a dealer or send it directly to EDDYCAM and receive a 10 percent discount when buying a new one.

Finally there is the LensPen.  It consists of a special cleaning tip and a lens brush that retracts into the pen for safe storage.  The cleaning tip surface is covered with a special invisible carbon compound that removes fingerprints and smudges. This is not “high tech” – this is “old tech”! Many years ago our grandmothers often used newspapers to clean the windows and mirrors in the house. Why did that work so well? Newspapers are covered with printer’s ink, which is about 25% carbon … and the carbon molecule has a unique ability to absorb oils. The invisible carbon compound in LensPen products is unique and it has been specially formulated to handle the fingerprint oils on lenses, filters, eyepieces and screens.


To use it first remove any loose dirt or dust off the lens with the built-in brush.  Then twist off the cap and wipe the lens surface with smooth, circular motion of the cleaning tip.  If some smudges persist, breathe gently on the lens and repeat the process.  At the end, simply twist the cap back on.

I have used all of the above methods over the years and all have served me well.  But most importantly, they have served my lenses well.  Even the oldest ones are clean with no scratches.  Treat your lenses well and they will give you almost unlimited years of good service.

A common sense approach in evaluating items for lens cleaning will always be helpful, but sometimes that is a commodity sorely missing. Years ago when I was working in a camera store, a customer of mine bought what was the most expensive 35mm camera at that time, a Zeiss Contarex electronic.  The gentleman was very busy and did not have a chance to use his camera very often.  For that reason, every time he was planning to do some photography, he came to see me first to get a refresher course on how to use his camera.  On one such an occasion, I noticed that all of his lenses were quire dirty.  They were all covered with a visible hazy smear.  During our conversation I told him that it was not my intention to tell him how to use or treat his expensive camera equipment, that, however, all the extra money he spent for his camera and lenses was lost because they were so dirty.  "No", he answered, "that's okay.  Someone who knows about this told me to properly cleaning lenses it is best to lick them."


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2 comments:

  1. I have heard on several occasions that people have repolished heavily scratched lenses. Is that advisable?

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    1. That ultimately depends on the lens; if it is an inexpensive one, I suppose this is possible. However, it is not advisable to do that with a Leica lens. To remove scratches by repolishing, you actually remove some of the glass from the surface to the depth of the scratches. This is way beyond the tolerances of Leica lenses. During their manufacture, Leica actually does not approach the final surface of their lenses until the coating is applied. With other words, the thickness of the coating is considered part of the total thickness and surface structure of the lens. Removing scratches by repolishing will actually go beyond that. In addition, the lens will also need to be recoated, a process that at Leica is subject to the same tolerances as the rest of the lens. Taking properly care of a lens is ultimately a much better approach.

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