EF Lens Cleaning

Discussion in 'Canon EOS' started by c._h._h., Aug 10, 2003.

  1. Hello,

    Can someone please tell me if cleaning a Canon EF lens to often will
    damage the coating on the lens? What type of coatings are Canon EF
    lenses made with anyways? I am currently using lens paper with lens
    cleaning fluid, and then lens paper with condensation from hot
    breath to finish the job. Is this the right way to clean these
    lenses?, or should I be doing it a different way? It seems to work
    great this way. What is more abrasive for cleaning Canon EF lenses,
    lens paper or lens cleaning cloth?

    Thank you,
  2. Good question, CHH. I've heard of people damaging their lenses by cleaning too roughly, but I'm not sure if they can be damaged by cleaning too often or not. I would bet that you get at least five different answers. There are some folks who hate lens tissue and others that abhor microfiber cloths. I use them both.

    I almost never clean my lenses, but then I keep UV filters on them for protection. I don't clean the filters very often either. When I do, I usually start with a little blow brush, then a half piece of lens tissue with one drop of cleaning fluid (on the tissue), followed by a soft wipe of a microfiber cloth (which I've thoroughly shook before using).
  3. Sounds fine, but you shouldn't be cleaning them very often. I've had lenses for 5 years or more that I haven't cleaned and which still look clean. If you're getting them dirty enough to require frequent cleaning you are doing something wrong or working under conditions where you should be using a filter.

    People do a lot more damage by cleaning lenses than by leaving them alone. Ever see those old cameras and lenses which are perfect except for "cleaning marks"! Lens tissue or a lens cloth is just fine as long as they are CLEAN and contain no dirt or grit.
  4. My understanding is that fluid is to be used as a last resort, and that lens paper is to be avoided altogether because it can be too abrasive.

    The two pros at my local store recommend a blower brush for dust, a clean microfine cloth (they're washable) for smudges, and a Lens Pen for specks.

    This drill has worked to keep my lenses clean, without apparent damage to the coatings, but I'll be interested in hearing about the lens cleaning techniques others use.
  5. There's nothing wrong with lens tissue. I used it professionally to clean laser optics which had to be *much* cleaner than any lens needs to be and which have delicate coatings and which are EXPENSIVE. The optics had to be rubbed quite hard with lens tissue to remove the final monolayer of grease or oil, as well as treated with methanol and acetone solvents. No damage occured, in fact standard laser manufacturer's instructions call for the use of lens tissue for cleaning optics.

    One advantage of lens tissue is that you use (or should use) a brand new tissue every time you clean a lens. You wipe the lens, then throw it away. If you need more cleaning, you get more tissue. Cloths work great if they are clean, but people tend to throw them in a camera bag and wash them once in a while, so they accumulate crap. It only takes one spec of grit too small to see to put a scratch in your lens.
  6. I was told by B+H photo to use a blower brush, and/or a microfiber cloth (not lens
    cleaning paper since it is more abrasive) You can pick up microfiber cloths for $4 at

  7. Bob- I'm curious what do you do with the laser optics? Is this for laser shows?

    On topic- I clean my lens surfaces maybe every few months at most, I usually have a UV or slight warming filter on. Getting to a recessed 50mm lens isn't fun. ;)
  8. Those fluids for lens cleaning are pretty much same as some of fluids used to clean contact lenses, but you should watch out which one since there's quite few different ones and some of them are quite agressive. Personally I try to stay away from that, and try to keep my lens clean, but if I do need to clean it I just use micro-fiber cloth and for now it works fine. Canon's suggestion about cleaning lens is on http://www.usa.canon.com/html/eflenses/lens101/lenscare/index.html.
  9. Lol, this guy has the same question 3/4 the way down this page, oh well, i post a lot of topics about what camera to buy, haha.

    Personally, I use a soft cloth, just like a cotton or fleece or whatever it is, and just rub gently from top to bottom. Like my science teacher said about microscopes, NEVER rub in circles.

    I also have an air brush thing, it's like a little pump with a brush on the end, this seems to get the lens surprisingly clean. Also, I have my goggle bag from my Oakley's that is very soft so I've been using it lately.

    Experiment with it on an old filter or something to find out which technique works the best for you.
  10. Yes, it'seasier to damage a lens by cleaning than to take less-than-perfect pictures through a dirty lens. While modern coatings (multiple ones, in Canon's case) are rather hard, they still can be scratched easily. As the surface of the front lens is far from the plane of focus under virtually all circumstances (exception: super wides at closest focusing distances), dirt on it doesn't affect image quality unless it's really large.
    How to clean?
    1. Use a blower brush to remove loose dirt. Do not use the brush for anything but photo lenses. Never touch the brush fibres with your fingers.
    2. Take a piece of cleaning tissue (or a micro fibre cloth), put a small drop of cleaning fluid on it, and gently wipe the lens surface in round movements, starting at the lens' centre.
    Skip #2 unless the lens shows smudges or other greasy dirt!
    3. Gently wipe the lens surface in round movements, starting at the lens centre, with lens paper or a microfibre cloth. Repeat as often as necessary. Do not use the tissue you used in #2.
    This should take care of virtually all dirt.
    Which products? For a blower brush, choose one you like. Wrt to microfibre cloth, avoid at all costs those for cleaning spectacles and/or binoculars; they're impregnated, i.e. heavily smear the photo lenses! Personally, I've made good experiences with Kodak Lens Paper. Cleaning fluid... oh well. In the end, I simply got isopropanol from my pharmacist. It works great.
    Labour-saving alternative: use protective filters and exchange them once a year.
    Those fluids for lens cleaning are pretty much same as some of fluids used to clean contact lenses.
    Huh? Some contact lens cleaners contact hydrogen peroxide, and some optics cleaners include ethanol or ammonia. Using isopropanol for my contacts would blind me, and when I study the label of my contact lens fluid, I detect some other substances I wouldn't like to have on my optics. Is that just because my cleaner is of the single step type (i.e. one fluid for cleaning and storage), or am I missing something?
  11. A photog prof told us that fluid should never be used on a filter as it will remove the coating. Anyone else heard this??
  12. Usual BS from people who don't know what they are talking about.

    Unless your lens cleaning fluid is hydrofluoric acid, or your lens has been coated with plastic to make it appear to be multicoated, lens cleaning fluids don't dissolve coatings. Now I'm sure that it's possible that sometime, somewhere, someone bought a bottle of something called "lens cleaning fluid" and used it on some lens that had some sort of cheap/defective coating on it and noticed sometime later that the coating appeared to be damaged. However that doesn't mean lens cleaning fluid damages lenses any more than someone, somewhere being stuck by lightning means you should never leave your house!

    I would use lens cleaning fluid if there was something really nasty stuck to the lens. Even then the technique is to wet the lens tissue and GENTLY wipe the lens, not to pour the fluid onto the glass. Lens cleaning fluids should be water based and neither do any damage nor leave any residue.

    Personally I sometimes use alcohol or acetone - BUT - you have to be very, very careful as acetone will dissolve most plastics. Alcohol is safer but it's still possible it could dissolve paint used on cheap lenses. If you don't know what you are doing and lack lens cleaning experince, I'd totally avoid such solvents and stick with "lens cleaning fluid" from some reputable source like Kodak.

    Breathing on the lens and wiping off the condensed moisture is also an excellent way to cleana lens. The condensed moisture should be very pure water and it will leave no residue.

    Lens coatings are vacuum deposited materials such as Magnesium Fluoride. MgF is used almost exclusively for single coated lenses, but multicoating uses other materials too. Coatings are fairly hard and not soluble in things like water or alcohol. They are applied by high temperature sputtering or evaporation of the materials in a vacuum, where they condense on the lens surface in a very thin (but well controlled) film.

    I cleaned laser optics because I ran a laser and optics lab at Bell Labs. That was my job. I have a Ph.D. in spectroscopy and spent 20+ years in optical materials research.
  13. In addition to Bob's answer: Most if not all lens cleaner fluids smell like isopropylalcohol which is probably a bit safer than ethanol. I don't know whether they contain other ingredients as well. It probably makes no difference on the lens coating but it's a bit safer on plastics.

    By the way, how about the lens pen? I bought one and was very reluctant to use it untill I saw it demonstrated at Photokina 2002. Seems to be safe and works well.

    Just my 2c,
  14. I clean my lenses all the time, both with lens tissue, and sometimes with a clean t-shirt when I am in a pinch. I have to clean them often because I like to shoot things close to the action, like mt biking and stuff. I was just in Alaska shooting the commercial fishing industry and had to clean them multiple times daily to get off salt water and fish scales and other junk. Call me lucky, but I have never scratched any of my lenses(visibly) through careful cleaning, and I only use filters on my big guns....
    I wouldn't worry too much about it.
    my 2 bits.

  15. You're lucky!

    Seriously, I'd probably use filters in those conditions. I was once shooting in geysers in Yellowstone and a gust of wind blew spray onto my (filtered) lens. Whatever that stuff is, it actually etched the glass of the filter in about 15 seconds.

    I don't normaly use filters unless I actually need a filter, but when there's crap flying around (dust, grit, stones, sea spray), I'll stick A UV or similar filter on the lens.

    I'll second the use of T-shirts to clean lenses though. They seem to do a good job and I more often have a T-shirt with me than a pack of lens tissues or a microfiber cloth!
  16. I just wipe with my T-shirt too, or use the lens paper. But lens papers leaves behind some of its "loose ends"(i dont know what to called it). But i always have the UV filter on, use my ts-shirt to clean in too. Of course, just be careful, not to have dirt or anything hard on it, you dont want have your name carved on the lens.
  17. I use a solution called Lensclens and it works superbly. Never streaks and does not damage coated lenses. You can read about it on Moose Peterson's website. It is made for coated lenses. Check it out at lensclens.com. I used it with very soft cotton fabric and a once over leaves the lens spotless and streak-free. I learned about it from other photographers.

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