Cleaning a lens?

Dave Dawson · Feb 22, 2009

Hi All, I have done a search on this site about cleaning a lens and to my suprise didn't find any advice (mind you my eyes are going )

Using a lens cleaning kit from a photographic store...the pack of tissues and plastic bottle of 'squirt' often make marks on the front or rear element surface worse rather than better.

Any suggestions on what to get from the chemist to shift those stuborn stains? I geuss pure alcohol will be in there somewhere??

Cheers Dave

paul ron · Feb 22, 2009

Denatured alcohol, micro cloth n a can of air.

keithwms · Feb 22, 2009

I blow first (dry air or N2), then use a lens cloth or lens pen (first a soft brush then the felt end) and as a last resort use lens tissue plus spectral grade methanol. If the solvent is not high grade or if there is a good deal of oil on the lens to begin with, then you can have marks.

I'd definitely not use acetone or rubbing alcohol or low grade ethanol... or water

keithwms · Feb 22, 2009

P.S. If you do have a lot of finger oil on the lens, you might try one of those oil-removing skin wipe things. In my area you get a pack of 10-20 blue, thin sheets in a little pocket pack, they are meant to be used for wiping the oily parts of your face. Anyway they "grab" oil fantastically well and what minor powdery stuff is left can easily be brushed or blown off. These sheets can take oil off lenses and rc prints too. I don't know what's on those pads but my suspicion is that it is forensic technology- you can lift fingerprints very easily with them!

Dave Dawson · Feb 22, 2009

Thanks....No oil, just years of grimme

Ed Sukach · Feb 22, 2009

My best advice: DON'T!!

A lens can have an amazing amount of crap on its surfaces with NO apparent effect on the quality of the image. Every attempt - EVERY attempt - at cleaning will have a detrimental effect on the surface of the lens - the first to be damaged will be the coating, then the glass itself.

The saddest sight in all of photography is to me the once beautiful Leica or Hasselbled lens with a large translucent spot in the center of the firrst element, the result of "knee-jerk" cleaning.

Keep a "plain" (Skylight, UV, etc,) filter on the lens. Then, if you MUST clean anything, every time (read: anally) you can watch the translucent spot grow on the filter, and know you have preserved your "good" glass.

IF I decide that there is no other alternative - every year or two, or three -and I MUST clean the lens itself, I will use clean water, and surgical cotton, being careful to use as little pressure (read: awfully close to "none") as possible.

keithwms · Feb 22, 2009

Ed, water is just about the very worst thing you can use on any lens. First of all, the lens surface will be hydrophobic, so water will not spread evenly, and moreover the [inevitable] contaminants in the water will immediately precipitate out onto the lens. Also, some of the AR coatings make this issue even more important. Finally, the most deleterious substance on your lens would be oil, against which water will do no good at all. If you must use water then you must also add surfactant or you will probably make matters worse.

That's why geek optics folks like me use spectral grade MeOH or EtOH with as much water removed as possible

Since I am already being a contrarian in this post, permit me to also disagree with your assessment that a damaged Leicablad lens is the saddest sight in all of photography. To me the saddest sight in all of photography is a fantastic lens with a UV filter on it. IMHO a person who is willing to pay the bucks for fantastic lens should also be willing to take the risk of letting the lens do what it can, in all its naked splendour.... as the lens engineers (and indeed, God Himself) intended for it to be used.

I will now dismount my soapbox

Alexander Ghaffari · Feb 22, 2009

I have been amazed with the power of graphite. I use those Lens Pens (name brand, do not trust knock-offs). Here is my procedure. Use brush on pen to brush away dust particles (if necessary). Breathe on lens, twist cap of Lens Pen, open cap, and use the graphite pad to clean going in a circular motion from the outside inward. You can have a lens coated in finger oil and the graphite takes it right off without leaving cleaning marks or scratches. The pens need to be replaced after 100 normal uses or so. If anyone knows a better way to clean a lens (besides doing nothing at all), please let me know.

I also use methyl alcohol to clean glass (like quartz cuvettes), but never my optical lenses (the less liquids that could get inside the lens, the better). Also, I agree that UV filters for "protection" defeat the point in obtaining a quality lens.

Disclaimer: I do not work or have investments with Lens Pen or any of its subsidiaries, assuming there are any.

John Koehrer · Feb 23, 2009

Lens cleaning solution, Kodak or Leland. Apply one drop to a wadded up tissue as per the instructions.
Ammonia used in the same manner all work well.
First rule: Don't apply liquid drops or spray directly to the elements. Apply it to the tissue.

Chazzy · Feb 23, 2009

It might be interesting to run a poll asking whether people leave a protective filter on their lenses or not. I think there only need to be the two choices, so setting up the poll would be easy. Maybe I will do it myself, if I can figure out how to do it!

DaveOttawa · Feb 23, 2009

Dave Dawson said:
Any suggestions on what to get from the chemist to shift those stuborn stains? I geuss pure alcohol will be in there somewhere??

Cheers Dave

If there is a "stubborn" stain it may in fact already be a cleaning mark, i.e. damage to the AR coating.
I would agree with the injunction not to clean unnecessarily, even if your cleaning cloth isn't abrasive it might pick up something that is and cause damage.
I find the microfibre cloths sold for optics cleaning are effective and safe on modern camera lens coatings (which are harder and more durable than ones from decades ago).
Blow off any dust with canned air or a blower brush first (read the instructions on canned air carefully).
If you want to use anything liquid you might start with "windex" window cleaner (vers slightly dampen your cleaning cloth only) since this will remove polar, non-polar and mixed soils. You may need to follow up with the highest purity isopropanol you can obtain since windex itself can leave stains.
Wipe from the centre to the edge of the surface.
(BTW I would vote for the no-filter-but-use-a-lens-hood-option)

BobNewYork · Feb 23, 2009

With the possible exception of B&W, filters don't meet the quality of good optics. Try two same-time photos - one with and one without. I have and there is a difference' albeit subtle. I do put filters on my lenses from transportation, but remove them before shooting.

Agree with DaveO re cleaning. As seldom as possible, (always blow off the lens after use) but whenever necessary.

Ed Sukach · Feb 23, 2009

keithwms said:
Ed, water is just about the very worst thing you can use on any lens. First of all, the lens surface will be hydrophobic, so water will not spread evenly, and moreover the [inevitable] contaminants in the water will immediately precipitate out onto the lens. Also, some of the AR coatings make this issue even more important. Finally, the most deleterious substance on your lens would be oil, against which water will do no good at all. If you must use water then you must also add surfactant or you will probably make matters worse.

... And the first raindrop falling on your hydrophobic lens (not protected by a UV ... or... barrier) will render it ... what? Useless? Let me redirect you to what I wrote - the important part is DON'T!! if at all possible.

Since I am already being a contrarian in this post, permit me to also disagree with your assessment that a damaged Leicablad lens is the saddest sight in all of photography.

Go ahead - disagree!! You are perfectly entitled to do so.

To me the saddest sight in all of photography is a fantastic lens with a UV filter on it. IMHO a person who is willing to pay the bucks for fantastic lens should also be willing to take the risk of letting the lens do what it can, in all its naked splendour.... as the lens engineers (and indeed, God Himself) intended for it to be used.

??? - WHO intended what??? I'll agree that the Optical Engineers were involved - I've known and worked with a few.
.
Uh ... Permit me to say that it somewhat presumptuous to assume the intent of the Great Creator. Possibly, in some grotto, on some Chapel ceiling ... we might discover a painting of the GREAT ZOT ripping a filter from a lens amid flashes of lightning and thunderous peals of thunder - so far I know of none even remotely applicable. Until I do, I'll limit any discussion to the engineers.

While I'm at it - I have never encountered ANY optical engineer with such a negative evaluation of filters. Period. As long as the geometry of the filter is reasonably sound there is/ can be - VERY little effect on the ray tracing and finally, image. Way back, I was presented with the idea that the thickness of a filter had a negative effect on image quality. As an experiment, I set up a lens on the optical bench, observed its characteristics - and introduced what would be an unreasonably thick filter, in the form of a double surfaced fused quartz optical flat. Fused quartz, with a HIGH refractive index, complete with "seeds" (small), and -- ~ 40 - 50mm thick. End result? No ... NO significant degradation of image quality.

Now ... Water is not appropriate for removing oils. True.
In trying to remember, I can't think of any instance where I have encountered oil contamination, Must be that my (demon) UV filters are woring well.

But then - there are those who would advocate the use of Drano and a grinding wheel...

We did have one techni ... uh, well not quite ... who decided to clean a lot of 20 specially coated (20 layers) lenses... his choice of cleaning media was a common pencil eraser.

He never got a second chance.

BTW ... Surfactant? Wouldn't that decrease the surface tension and increase the possibilty of accidental incursion ito the innards of the lens?

Anscojohn · Feb 23, 2009

[
Any suggestions on what to get from the chemist to shift those stuborn stains? I geuss pure alcohol will be in there somewhere??
*******
Canned air; camel's hair brush. Look at surface obliquely to make sure all grit is off. Breathe on lens; use a brand new cotton swab. If this does not work. a drop of Vodka on another brand new cotton swab. Drink remainder of vodka AFTER cleaning lens.

I have IA-type filters on almost all of my lenses. And I remove them whenever I intend to take pictures.

keithwms · Feb 23, 2009

Well :rolleyes: it's up to me to decide what "significant degradation" is when I use my lenses. Right? And to me any unnecessary degradation... and anything in the light path that increases the likelihood of flare etc.... is unacceptable.

Once I bought a really nice lens; the seller boasted that the thing had always been protected by a UV filter! Wonderful, right? Wrong. Turned out the damn filter -which had fingerprints on it- was stuck on there. I had to dremel it off, and it was basically impossible not to damage the lens threads while doing so (took much longer than an ordinary circumcision). Mind you, this is even more of an issue now with the plasticky lenses that easily crossthread. Buyers of "protective" filters beware: the solution can easily become the problem, and then what? Lenscaps are for when the lens isn't pointing at a subject; when the cap is off, just use a hood and be happy.

Anyway, back to glass cleaning theory...; ) surfactants micellize crud. That's why soap works in the shower. Water alone does not take off oil, and oil is what causes crud to stick so strongly that you cannot simply blow it off, so....

Accidental incursion of fluid into a lens is not an issue with MeOH and EtOH, assuming of course that it's done properly (by applying the solvent to a microfiber cloth, as people have suggested). These clean solvents have high vapour pressure and are gone almost instantly. They are readily available in purity levels high enough to leave no residue.

Dan Dozer · Feb 23, 2009

I use a product from Freestyle called Eclipse Optical Cleaning System along with PEC Pads, and it's far and away the best I've ever used. This stuff is amazing for getting all the final marks, film, oil, whatever off the glass. I've cleaned old Cooke and Dagor lenses that I thought were fogged and they turned out looking like new.

I used to think Kodak lens cleaner was good, but this stuff makes Kodak lens cleaner look like crap. It contains Methanol which is a nasty very flammable solvent - don't smoke around it. However, you're only using a couple of drops at a time so it shouldn't be at all hazardous (just be careful not to get it in your eyes or drink it).

Now - I'm assuming that since this is made for optical cleaning that it won't harm the coatings on modern day lenses. I've used it on old uncoated lenses and new coated ones with equal results. I highly recommend it.

Poohblah · Feb 24, 2009

I've tried many of the suggestions above and I've never achieved satisfactory results. I prefer simply replacing the lens cap as often as possible.

23mjm · Feb 24, 2009

For me it is the Eclipse Optical System and PEC pads. This works the best IMHO. One thing I have found is that if the lens has finger prints/oil you need to use a few pads, don't keep using the same pad. Wet it wipe it replace it and repeat.

I to try to keep the hood and cap on as much as possible, but there are always the times like---looking at a scene and reaching to take the lens cap off only to realize that it is already off and now you have a few nice finger prints on your filter. Oh yea I always use filters--good ones.

Ed Sukach · Feb 24, 2009

keithwms said:
Well :rolleyes: it's up to me to decide what "significant degradation" is when I use my lenses. Right?

Absolutely correct!!

... And it is up to ME ... when I use mine ... etc., etc.

... And to me any unnecessary degradation... and anything in the light path that increases the likelihood of flare etc.... is unacceptable.

Zounds!! This PROVES that you and I are different!! - Although it seems apparent that no proof was necessary in the first place.

... the damn filter -which had fingerprints on it- was stuck on there. I had to dremel it off, and it was basically impossible not to damage the lens threads while doing so ...

Sad!! There is a method with a prick (not attempting to be funny re: the "circumcision" reference) or center punch and a jewelers hammer - envision the mechanics of an impact driven screwdriver. A very gently driven impact screwdriver. MUCH gentleness!!!
With patience, that has never failed me.

As to the Dremeled filter threads - Are they a great loss? I don't suppose you would use them anyway.

Anyway, back to glass cleaning theory...; ) surfactants micellize crud. That's why soap works in the shower. Water alone does not take off oil, and oil is what causes crud to stick so strongly that you cannot simply blow it off, so...

An interesting observation - but a solution for a problem I don't have ...

Steve Roberts · Feb 24, 2009

At the Earl's Court Broadcast Video Expo last week, I came across a firm (True Lens Services) who specialise in repair and maintenance of lenses. In an FAQ on a handout, one question was of course "How do I clean the glass?" Answer: "Better still, don't get it dirty in the first place! But if you do, start by using a puffer bulb to blow away as much debris as possible without touching the glass. Then gently use a camel-hair brush, starting in the centre moving in circles towards the outer edge. When there is no evidence of dust or dirt, use a lens cleaning tissue with an appropriate cleaning chemical."

I'd add to that a) as has already been said, a lot of surface debris can accumulate before becoming a problem, and usually then only when shooting into the light. b) when brushing the lens, hold it upside down so that debris falls away from the surface rather than just being distributed over it. c) lens tissues have never impressed me - they are usually too hard and crinkly to follow the surface of the lens without excessive pressure. I prefer Tomosy's approach of using a plain soft, facial tissue, with just a bit of heavy breathing (!) on the lens unless any grease was involved.

Steve

Dave Dawson · Feb 24, 2009

I certainly seem to have started a debate on the virtues of 'lens care' in the form of lens caps, filters and lens hoods BUT what I was more interested in how to remove smudges on a second hand lens that already has marks on it.

I remember buying a second hand Rollieflex e3 tlr with f2.8 Xenor taking lens from a local photographic store. When I first looked at it both the viewing and the taking lens looked grubby. When I mentioned this to the man behind the counter he said "No problem sir I'll get our repairer to clean them" When I returned a few days later to buy it, both lenses looked like new...I have wondered to this day what the repairer used????

Thanks for all your suggestions. Cheers Dave
ps....All spelling mistakes are deliberate !!!!!!!!!

Philippe-Georges · Feb 24, 2009

Dave, he might have used this : https://photo-shop.zeiss.com/epages/cz.sf/en_GB/?ObjectPath=/Shops/CZ/Categories/Zubehoer/Cleaning

Philippe

Jeff Kubach · Feb 24, 2009

I sandblast my lenses!

Jeff

keithwms · Feb 24, 2009

Ed Sukach said:
... And it is up to ME ... when I use mine ... etc., etc.

Agreed.

The debate (if any) should be: why do you do what you do. Generally, those people who are attempting to be helpful to newcomers will offer clear explanations.

Fotoguy20d · Feb 24, 2009

I was in a Walmart once and picked up a box of Zeiss branded optics cleaners for around $3 for a pack of something like 50. Basically, similar to the hand wipe pads. Some sort of alcohol on them and a soft "cloth". That being said, I won't use them on my lenses. I use them on the "cheap" filters that protect my lenses (already contributed my thoughts to the poll).

I've gotten some really ugly vintage lenses on ebay (optars, steinheils, tessars) and Windex and a soft cloth has done wonders.

Dan

Cleaning a lens?

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