How To's

The Lensrentals Lens Cleaning Methods

Published May 15, 2011

There are some articles I try hard to avoid writing. Politics, religion, the so-called benefits of UV filters and other things that get Fanboys riled up I avoid like the plague. So for two years, while people have asked over-and-over for me to write an article on how we clean lenses, I’ve politely refused. I’ve seen what happens to such discussions on forums — it’s an immediate call for all Fanboys to come tell everyone else they’re an idiot because they don’t use Eclipse, or do use Eclipse, or brush before blowing, or blow before brushing, or whatever.

But I’ve had over 100 requests now, so I’m finally going to cave in. Since I’ll be mentioning and recommending some products by name, my usual disclosure applies: we use what we use because we like the product, sometimes a lot. Unlike 99.9% of the internet we don’t get discounts, kick-backs, click-through fees, or sell any of the things recommended at a profit. I don’t put any links to the products to make sure that’s clear. You can find it all with a quick Google.

 

What this is:

Mostly it’s proof that the old saying “Be careful what you ask for. You might get it.” is true. This is going to be massive overkill for 98% of people who asked how we clean lenses. You certainly aren’t going to go out and buy all the supplies to do this to your own lenses every day (well, except for a few of you that have major Lens OCD: you know who you are). But there will certainly be some things you’ll want to try, and probably a few tools you don’t know about.

On a busy day we clean about 500 lenses, on slow days maybe half of that. We clean to what for most of you would be an unreasonable standard – not just the front element but the entire lens. Over the years we’ve probably tried every cleaning method there is short of kerosene and a blowtorch and we’ve considered that once or twice. That doesn’t make our way the right way. It just makes it a way that works well for us.

What we use:

I’ll start with a photo of one of our cleaning stations so you get an idea of how over-the-top our cleaining methods are. You may want to just say never mind and move along now. Or if all you want to know about is how we clean front elements, skip down toward the end of the article.

Supplies at a Lensrentals Cleaning Station

Don’t get me wrong, you don’t need half of this stuff. A lot of it is useful to us only because we do so many cleanings a day, and some of it because some of our techs prefer one thing to another. But for completeness, here’s what we have at each station, using the numbers in the picture to give you location:

1: Large yellow chamois, Zeiss individual lens cleaning cloths in box, and blue microfiber cloth.

We use the chamois for cleaning barrels and cases. We don’t usually use microfiber cloths on front elements: you never know when there might be a piece of grit in them which could scratch the elements. We use fresh Pec Pads for that. But microfiber cloths are more absorbant and we will occasionally use a new, clean one on front elements.

2: Lint removing brush (red) and two size lint rollers above it (Sensor Loupe above that doesn’t count in this article).

Used for cleaning bags and the inside of lens hoods (the ones that have a felt lining).

3: Giottos Rocket Blower. The one thing everyone should already own.

4: Cleaning solutions — Eclipse, ROR, Purosol Lens Cleaner, Purosol Sport and Marine cleaner. Two canisters of premoistened electronic cleaning wipes behind them.

Purosol cleaners and electronic wipes are used for the outside of lenses, hoods, and caps. We occasionally, but not often use Eclipse or ROR on lens elements. ROR is especially good when there are oily deposits.

5: DataVac Electric Blower. The greatest invention ever made, but you probably don’t need one.

We avoid canned air: it can have propellants or other liquids that can stain glass (and it’s relatively expensive in quantity). The DataVac Electric blower is the only thing we know of that uses no propellants or lubricants plus it’s EXTREMELY powerful. Many times greater airflow than canned air. We use the Rocket Blower for sensitive places like front elements, the DataVac is too powerful. But for about $50 it keeps us all from getting carpal tunnel syndrome from pumping the Rocket Blower all day.

6: 8 different sizes and types of Lens Pen. Notice the large rectangular LapTop LensPen just to the right of the chamois, just to the left of the “6”. More on LensPens later.

7: Two toothbrushes and in the lower right corner Pec Pads.

Soft toothbrushes are the only way to get dust and grit out of the cracks and crevices of front lens caps (Canon caps are particularly prone to gather it). A toothbrush and Purosol cleaner does a wonderful job of cleaning the grooves of rubber zoom and focus rings. We use Pec Pads instead of microfiber cloths on front elements: we know a fresh Pec Pad doesn’t have any grit on it. That’s hard to say about a previously used microfiber cloth.

Cleaning Overview

Our basic method is cleaning from outside in: Case or pouch, then outside of the lens, the caps, and finally glass. There’s no sense cleaning the lens barrel and then putting it back in a dirty case, or cleaning the front element and then putting a dust filled lens cap back on it. Cases are the easy part, of course. Simply blowing them out with an electric blower or vacuuming them takes care of dust, and a lint brush or roller handles anything left over. Canvas type cases, in particular, look much better after a good vacuuming.

The Lens Body, Hoods, and Caps

Obviously cleaning this doesn’t make the lens work a bit better, but it’s nice to have a clean lens. And it’s definitely worthwhile for a lens you plan on selling. The plastic and metal on the outside of the the lens barrel, hood, camera bodies, and caps are easily wiped clean with a chamois dampened with cleaning fluid. We generally use Purosol. It’s not the strongest cleaner but it leaves no residue and doesn’t seem to cause any adverse effects on the rubber zoom or focus rings, or plastic distance windows. Tough areas are spot cleaned with a premoistened electronic wipe or a bit of eclipse.

The inside of hard plastic hoods can be cleaned in the same manner, but lint rollers or brushes are the best way to get dust and dirt from the inside of felt-lined hoods, particularly supertelephoto hoods. The inside of clip-on front element caps get the dust blown out of course, but dust tends to hide in the nooks and crevices of many caps, and inside the spring loops of Canon caps in particular. Brushing with a dry toothbrush usually dislodges it so it can be blown away, or a toothbrush sprayed with cleaner used to get the tough dirt out.

Front Elements

This is what most of you want to know about. The key to front element cleaning is to avoid damage. Blowing is always done first. You can’t scratch an element by blowing and most large particles can be blown off using a Rocket Blower. (Canned air or a DataVac is really too strong, and as mentioned earlier it’s possible to get some residue on the element using canned air.) Brushing (we use the brushes on the LensPens) is always done second to dislodge any particles, followed by blowing again to remove any particles loosened up by the brush. If further cleaning is needed after blowing and brushing, that’s fine, but blowing and brushing is always first.

Our next step revolves around LensPens. We like several things about them: no liquid residue, simple and easy to use, gets into the edge of the lens better than most other methods. And out of the office, they’re small and easy to carry around. They come in a variety of types and sizes and we use a number of different ones. Smaller ones are perfect for camera viewfinders, angled edges are great for lenses with deep edge recesses like fisheyes, etc.

A variety of LensPens sizes and types. On the left is the Laptop Lenspen, which we find perfect for supertelephoto front elements. Notice the two on the right: when you start to see them look like this, it's time to throw them out. Actually the one that's next to the Laptop LensPen is about ready to go. When you see rubber instead of felt around the edge, the LensPen is used up.

The key to using a Lenspen is that you charge it (put the cap all the way on and take it all the way off) with each use so that the tip gets more cleaning dust. Also after using the lens pen, you should go back to blowing and brushing: if you look carefully with an angled light, you’ll see a little fine grain dust has been left after the Lenspen use.

The most important point, though, is to not overuse a Lenspen. Once the felt on the tip gets worn, the rubber underneath doesn’t clean, and can leave marks if used with too much pressure. We get, at best, 100 cleanings from a Lenspen, but that varies by which brand we’re using and how big the lenses are being cleaned.

Lenspens do a great job on routine dirt, streaks and grime, but they won’t get more stubborn “stuck on” gunk off of the front element, and aren’t great with oily residue either. A wet cleaner is required for this stuff. We use Zeiss disposable lens cloths — individual sealed pouches with a lens paper moistened with cleaner inside. We like that these are single use. Like I said, we’re more paranoid about a piece of grit on the cleaning cloth damaging the lens than anything else. They’re also convenient to toss a couple in your camera bag. But Eclipse on a PecPad works just as well, and ROR is what we reach for when we see obvious oily residue on an element.

PecPads are single use, too, and we like that, but they aren’t as absorbant as a cloth. When we’ve had to use a fair amount of wet cleaner, sometimes a microfiber cloth is used to wipe off the cleaner simply because it’s easier to get the streaks off than PecPads are. You may have noticed a microfiber cloth on the desk in my first picture: that cloth wouldn’t be used on a lens element, it would be for less critical things like LCD covers. Only a clean, been-kept-in-a-pouch microfiber cloth should touch a front element.

Many of you know we don’t get freaked out about tiny front element scratches. We test to make sure they don’t cause flare or contrast loss and otherwise don’t worry with them, they won’t do anything else. But a lot of people, including perhaps the future buyer of your used lens, will care a lot, so it’s worth trying to keep the element as pristine as you can.

Rear Elements

Cleaning rear elements is certainly more important from an image quality stand point than front elements, but since rear elements aren’t exposed to the environment it’s rarely necessary to do more than blow off dust. Many lenses are “rear focusing” so before cleaning the rear element turn the focus ring to bring the element up to the surface of the lens.

If more than blowing and brushing is required, be careful to keep your fingers away from the electrical contacts on the lens when cleaning. Just a bit of skin oil on the contacts can interfere with electrical signals transmitting between camera and lens. If you do find an ERR message after cleaning a lens, you can lightly rub a clean pencil eraser over the contacts to remove the oil. There are people online who give longwinded warnings about this eroding contact metal, and it might if you do it every day, but every factory repair service we know of uses that technique, so we do to.

Is All This Necessary?

Absolutely not. Those of you who wear glasses just take them off and look at them. They can be fairly filthy and not interfere with your vision. The front element of your lens can also be fairly filthy and not affect image quality at all. If you don’t believe me go put a a couple of 1/4 inch wide piece of post-it note on your front element and take some pictures. You won’t be able to tell it was there, any more than you can tell a fair amount of dust is there. Or look at our example or Kurt Munger’s. That being said, very wide angle lenses at small apertures may be the one exception to the rule: the depth of field in that case may come close to bringing front element dirt or scratches into the plane of focus. Maybe.

Oily films or haze or thick coatings of dust can definitely affect image quality, though, and probably should be cleaned as soon as possible. However, lots of small scratches can affect contrast and deep scratches can cause lens flare, so the key is to keep your lenses reasonably clean but avoid putting multiple cleaning scratches on the front element. So we believe blower, brush, and meticulously clean (read single use) cloths for cleaning are the key.

But that’s just our opinion. We know breathing on the lens and using the corner of your T-shirt usually works. Almost any cleaning method usually works and has it’s advocates. Just letting the lens be incredibly dirty usually works, too. But most of us (and as best I can tell all of our customers) like their gear to look as good as it did when they first got it, and these are the methods we use to do that.

A note on comments

With a bit of hesitation, I’m leaving the comments section open in this article. Thoughtful comments, questions, and suggestions are welcome. What I’ve written above is the way we’ve performed some 120,000 cleanings, but that doesn’t mean I know it’s the right way. The only thing I know for certain about cleaning lenses is that sandpaper and chisels should be used, at most, sparingly. Everything else is open for discussion.

But this isn’t a forum, it’s our clubhouse, and we don’t find the “anyone who doesn’t do it my way is an idiot” type of comment acceptable. There are already plenty of forum threads about cleaning lenses that are full of those posts, there’s no need for more. Of course, anything that hints of “selling a product”, even the ones we’ve recommended, in the comments will be deleted immediately. Our readers are big boys and girls, they know how to use Google to find what they want.

Roger Cicala

Lensrentals.com

May 2011

 

Author: Roger Cicala

I’m Roger and I am the founder of Lensrentals.com. Hailed as one of the optic nerds here, I enjoy shooting collimated light through 30X microscope objectives in my spare time. When I do take real pictures I like using something different: a Medium format, or Pentax K1, or a Sony RX1R.

Posted in How To's
  • Not too long ago there was some discussion about not breathing on the lens to clean it (the hhaaahh we do on our own glasses) as it would damage the coating. Any feedback on that? Based upon this article, it seems better to wait to get home and clean it proper unless simply coated in mud at which point the breathing trick would simply help ruin the lens.

  • Roger Cicala

    C.A. – no opinion other than to say saving money on front element cleaning supplies is like buying cheap locks. If you are only protecting cheap stuff or have great insurance than using cheap locks is probably fine. If you only have cheap front elements use anything you like.

    Isoproryl alcohol is probably fine as long as your careful with it. But remember it also dissolves the glue around the screws that hold your front element in place.

  • Roger Cicala

    C.A. – no opinion other than to say saving money on front element cleaning supplies is like buying cheap locks. If you are only protecting cheap stuff or have great insurance than using cheap locks is probably fine.

  • C. A. Hudson

    I have heard that using 91% isopropyl alcohol from the pharmacy, with a new microfiber or lens tissue (or even good soft bath tissue) is safe to use on front and rear elements – and is economical.

    Your opinion vs. the other methods?
    Thanks.
    Chris

  • bemoo

    @Hal

    The other Zeiss wipes are for cleaning windows, do not use them for lenses. Your lenses will vaporise if you don’t use the right one.

  • Tonio
  • Hi, thanks for the informative website! Would you be willing to clean (what I think is fungus) from inside a Sigma 17-35 A spherical? I really hate to loose it Thank you, Tim

  • Hal

    There are at least three different types (or names/packaging) of the Zeiss disposable pre-moisturized tissues:
    – Zeiss lens cloth
    – Carl Zeiss cleaning cloth
    – Zeiss lens wipes

    From the photo I see a box of “Carl Zeiss cleaning cloth”, so is that the safe one for lenses (not harmful for multi-coated optics) and are the other Zeiss tissues only for glass tables, glasses etc. or are they all the same?

  • Marco Debiasi

    Roger, only recently I read this article and I have a question. You explain that, after using the lens pen, one should go back to blowing and brushing to remove the cleaning dust that may have been left on the lens surface. But then, I wonder if blowing such extremely fine dust can push some of it inside the lens. In your answer above to Lee Saxon on May 16, 2011 you explain that “many lenses have open areas under the plastic seal around the edge of the lens and dust can get in that way”. Can you suggest any other safe way to remove the lens-pen dust?

  • I get conflicting info… Is using isopropil alcohol good or bad for lenses and what about filters?

  • Roger Cicala

    Hi Sara,

    Other than blowing dust off the mirror, we leave them alone. They’re easy to scratch and easy to bend – and a bent mirror can make focusing a real issue.
    Roger

  • Sara

    Hi, Thank you for the help this article provides with cleaning the camera and lens. I had a question, and at the risk of sounding like an idiot (have a Nikon FM10 which has been in hibernation in the attic which I got down yesterday), the mirror when you remove the lens seems to be stained as well as when I look through the lens when removed, it seems dusty. What is the best way to clean the mirror easily (the manual says use absolute alcohol to clean glass surfaces – don’t know where I could find some). Could you please advise on what I could do? Also I live i France and am not sure of the equivalent of the cleaning products mentioned – sorry.

    Thanks for your help.

  • Roger Cicala

    Tom, all of those solutions work just fine. I usually follow the Zeiss premoistened with a Kim wipe these days. Love those things. Cheap and laboratory grade.

  • Roger Cicala

    Tom, all of those solutions work just fine. I usually follow the Zeiss premoistened with a Kim whip these days. Love those things. Cheap and laboratory grade.

  • tom graham

    Great article Roger, thanks. I have referred many discussions about lens cleaning to it here.

    Like Jason, I also see a film left by Zeiss pre-moistened packet cloths. Any concerns about that? An out of-the-package lens tissue (now sold by Tiffen, not Kodak) to “mop” up that moistness works good. So does the distilled water, isopropyl alcohol, drop of Dawn solution. (Used by telescope folks).
    Tom

  • Jason J

    I use the Zeiss pre-moistened cloths but they see to be too wet. They leave a streaky residue. Have you had this problem? Seems I need to wait for them to dry out some or use a microfiber to finish up with before it dries.

  • Ed M.

    Nice writeup. I was an optical instrument/submarine periscope repairman in the Navy for 22 years…..I’ve cleaned my share of lenses. I’m also an amateur astronomer and clean my telescopes. I’ve made and used collodion. I can understand your reservations about posting this, I no longer get involved in forum discussions regarding lens cleaning. My weapons of choice include Purasol, ROR (which I REALLY like for fingerprints), a few drops of Dawn in a cup of water (again, for fingerprints), acetone to clean off the film left by Purasol, ROR and Dawn. It is of course not how I clean sensors, though.

  • Zygmo

    Hey…you think camera guys are picky about cleaning glass…try owning some telescopes!!

    However…I read a funny story recently. It is said by the astronomers who use the largest (usable) refractor lens telescope in the world; the Yerkes 40″, is cleaned by throwing a bucket of soapy water on it, and scrubbing with a brush!! Then another bucket of water to rinse. Sends chills down my spine!

  • quartzie

    I’m sure there will be some people itching for the Datavac “just because” it’s a powertool 🙂

    Otherwise, great article, good ideas for lens exterior cleaning.

  • Randy

    Thank you, Roger. If anyone is in a position to know when and how to clean lenses, it’s you. One of the very few things I learned from years of reading Popular Photography was “Its better to keep your lens clean than keep cleaning your lens”.

  • Alan

    Interesting and comprehensive, but: the lint removing rollers you discuss work because they are coated with an adhesive, some of which rubs off onto whatever you’re delinting. Over time, this turns the object you are cleaning into a lint magnet. The Velcro brush you show in the picture is a much better bet, plus it’s easy to clean, whereas the rollers are impossible to clean.

  • Wonderful Read! I was researching that for many years and I found your way useful for me.. Keep it up!

  • Roger Cicala

    Sarah,

    I think we are in total agreement, but approaching it from different sides: I see far more people scuffing the front element of their lens in an effort to make it sparkling clean than I do people letting their lenses remain filthy. My experience is it takes an amazing amount of dust to reduce contrast and introduce flare, but just a thin film of oil or grease has a huge effect.

    Roger

  • Good article on lens cleaning. Thanks!

    However, I’m surprised you claim that a clean lens is unimportant. I similarly hate the “dirty lens article” that claims even post-it note blobs will go unnoticed. Why do you perpetuate this myth?

    The fact is that dust and dirt diminishes contrast and introduces flare with frontal light. More conspicuous blobs, scratches, etc. can become somewhat visible in a photo when using small apertures. Of course, if you only use relatively large apertures, and if you never get bright light on the front element of the lens, I suppose there would never be a problem. My own photography is more varied than that.

    I think there’s a case to be made for keeping a moderately clean lens (particularly clean of residues/films) and getting it relatively much cleaner (usually with a blower and soft brush) for any shots into bright light. Chasing every last speck is better left to someone with OCD. Photography is one pursuit in which all the little details add up, either for the better or for the worse.

  • Pete S

    Great article!

    My solution for compressed air is to use scuba air, nitrox compatible to be precise. It’s very clean – much cleaner than the air around you – because both water vapor and dust and other contaminents are filtered out through several active carbon filters. So I guess it’s even better than the datavac. One regular sized scuba tank holds 80 cuft of compressed air (about 10000 puffs with the large rocket blower). When it’s empty you need a refill.

    I use it for cleaning the sensor (with great care – not to destroy the shutter curtains), the lenses, caps, bags and cleaning film when scanning.

  • Colin

    Good advice. I spent five years working in a camera store that specialized in used equipment, and we cleaned a lot of lenses and equipment. We used essentially the same procedures you guys do. Blow, brush, (we used natural hair brushes from a artist supply store-not man-made material) and stopping there will do the job 98% of the time,

    My little hint: If you ever get some corrosion on a battery contact, mix a lot of baking baking soda and a little warm water (saturate the solution) and apply small amounts with a Q-tip, while holding the device so that all drips will fall out of the device. Messy, but it will remove the corrosion. Rinse with plain water, of course, and let dry for a day or two before use.

  • Andreas Helke

    Even relatively minor dirt particles on the front element will show up as a shadow at the wide angle setting of an 17-55 or 18-55 lens, Dust particles on the back element will show on tele lens photos too. Fortunately its rare that the back element aquires them. Real lenses seem to work a lot different than the simplified theoretical models used in a physics course.

    Fortunately the dust particles on inside elments of your lens usually obey the simplified laws of optics and don´t produce visible shadows.

    Here is a test photo from my 17-55 f2-8 at 17mm f22. The one dust particle on the front element produces a very noticeable shadow. The several similar sized dust particles inside the lens don´t show up in the test photo. http://www.flickr.com/photos/andreas_helke/2533361729/

  • Edwin Herdman

    I just got linked this article. Great stuff!

    The only lenses I’ve actually cleaned so far have been my poor Canon 50mm f/1.4, and since then I haven’t touched it again, and my TS-E 17mm (but not in a long while). So far, I have stayed simple: An old fine hair brush at the end of a rubber blower (a bit like the rocket, but with a brush at the end) that was in a cleaning kit with some stuff I would never use (an unopened bottle of cleaning fluid from the 1980s, at best, some q-tips, some thin yellow cloth that again I wouldn’t use on a lens). The fluid I used is 99% isopropyl alcohol. I already had a yellow 3M microfiber cloth that I had to try to clean off the bed of a scanner. If I had to do things over again, I wouldn’t do half this stuff now.

    I haven’t needed to clean the 50mm in a long time because I simply left the cap off and left the lens hood affixed instead. It’s a good lens hood and serves the purpose well of keeping stuff away from the lens. When I was constantly putting the lens cap on and off, I occasionally hit the front element with my fingers, oops!

    I also learned not to blow on the lens because it’s extraordinarily hard to keep tiny dots of spit from coming out. Also bad!

    So, right now all I do is use the blower to jet little bits of dust off the front as necessary. If it doesn’t want to move, I hit it some more with that air. I flick out bits of dust on the recessed ring around the front element with the brush part.

    So far, I haven’t ever had to clean my Sigma telephoto zoom or my TS-E 90mm. Perfect shape, dust just flicks off of them. Haven’t used them in rain though.

    Also worth mentioning that for the clueless amateur, aside from cleaning as infrequently as possible, it makes a lot of sense to only clean the actual spots that need cleaning. Just dripping some isopropyl alcohol on and tapping the 3M cloth more or less does it.

  • michael

    i’d worry about acetone removing lens coatings, and it would almost definitely harm any paint finish/plastic parts on the barrel if it got on accidentally.

    this blog post more or less follows how i’ve cleaned lenses for the past 5 years or so. has always worked well for me!

  • Jon

    By far the best liquid cleaner I have used is 100% acetone (no lanolin content). Just be aware that this is what is used for finger nail polish (paint) remover and I ONLY use it on the glass surfaces. It removes any oil or gunk and leaves no residue. It also dries so fast, you literally can not see a wet surface. I have seen lens manufacturers use acetone during lens assembly, so I would assume it is safe for most lenses – however proceed at your own risk.

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