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cleaning without harming coating (1 Viewer)
- Thread starter MattMatt
- Start date
Any optical cleaning fluid made for coated camera lenses should be okay. Just make sure that you apply the fluid on the cleaning paper and then apply the paper to the lens. Paper is to be used only wet, never dry (so you cannot dry the lens with it). Don't put drops of fluid directly on the lens itself. The fluid is part solvent, and if it seeps down into the edges of the lens it could loosen the adhesive used to keep the front retaining ring from coming off.
As for other substances, it is imperative to avoid any window cleaner as these are made with ammoniac and might damage the coating. I also avoid methanol, as it behaves like a painting solvent. And finally I avoid ethanol, not because it would damage the coating (it never will), but because it leaves cleaning traces on the glass.
As for other substances, it is imperative to avoid any window cleaner as these are made with ammoniac and might damage the coating. I also avoid methanol, as it behaves like a painting solvent. And finally I avoid ethanol, not because it would damage the coating (it never will), but because it leaves cleaning traces on the glass.
I would be very careful abouot applying ANYTHING to expensive lenses. I went into a "proper" camera dealer to ask about cleaning fluids (just yesterday, in fact!) and when I mentioned that my scope had ED glass was told it would be better NOT to use "normal" camera lense cleaning fluids. I also e-mailed Opticron seeking advice and was told to get rid of dust etc by using a lens brush and then to BREATH on the lens before wiping gently with a good quality lens cloth.
regards
Gordon
regards
Gordon
Michael Frankis
conehead
If you've been seawatching, it is very important to get LOTS of 'breath' on the lens before wiping. The tiny salt crystals that inevitably get on the lens anywhere close to the coast are very hard and scratch the coating easily if wiped off, so it is essential to get enough water on them to dissolve them completely before wiping. Actually, salt crystals are so hard they'll scratch the glass under the coating as well.
When I've been seawatching I usually rinse the lenses off first with plenty of water, before wiping.
Michael
When I've been seawatching I usually rinse the lenses off first with plenty of water, before wiping.
Michael
Doug Greenberg
Well-known member
There is a product called "ROR," or "Residual Oil Remover" that is excellent for that "once in a while" cleaning of delicate optics. I have used it on my ED lenses with great success. The trick is to use it only when absolutely necessary (i.e., rarely) and in very, very tiny amounts.
My alternate suggestion echoes the other posts. A bit of breath, but with a Lens Pen or a microfiber cloth.
My alternate suggestion echoes the other posts. A bit of breath, but with a Lens Pen or a microfiber cloth.
MattMatt said:
I think there's an older thread about this somewhere. Some scopes have hard coatings applied to exposed optical surfaces. I know that Leica use quartz and Swarovski have their own Swarodur, whatever that is. Leica and Swarovski recommend using a lens cloth and breath which probably testifies to the hardness of their protective coatings. The main thing to watch out for is grit. If you clean a lens with grit on, or using a cloth with microscopic grit embedded in the fibres, then you could scratch the coatings.
I take a rather cautious approach. I first blow off grit with a hand blower. Then I clean with a grit free pad and lens solution. I prefer to use sterile cotton swabs and isopropyl alcohol (in the UK obtainable from Maplin), though isopropyl alcohol and distilled water 50:50 would be better. Many supposed glass cleaning fluids such as the stuff sold at opticians have too many impurities. Whatever you use, its best not to apply too much pressure, but rather drag the pad over the lens. Discard the pad after a couple of wipes. I also permanently use a clear Canon Protect filter on the scope so I clean the filter and not the objective.
You could of course take the view that the filter can be treated a bit more roughly, and then just ditched and replaced with a new one after a year or two if need be.
Anyway, whatever you do, it's best to avoid cleaning if you can. A little dirt on the objective is probably of little consequence.
FWIW that's my sixpence worth ...
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Michael Frankis
conehead
Hi Leif,Leif said:
Salt is a lot worse than grit - (1) it is harder than most grit, (2) because it is deposited in solution and then dries to crystals, it doesn't blow off, (3) salt is not soluble in isopropyl alcohol, so it'll still be as hard, sharp crystals, and (4), you often get quite a lot of it on the lens, so not cleaning is simply not an option, after a few hours' seawatch you can't see out of the scope, you can see the white coating of salt crystals on the objective
Michael
Michael Frankis said:
Michael: That's why I suggested 50:50 isopropyl alcohol and distilled water, the salt being soluble in distilled water, though I don't sea watch so it's not an issue for me. Your solution, of washing in fresh water first is probably even better, assuming a waterproof scope, of course. I can't imagine your objective would last long given the conditions you describe!
scampo
Steve Campsall
I am a bit of a clean lens freak and have come to the conclusion that a good blow with a powerful puffer device, possibly follwed by a flick with a clean lens brush if needed then, and only then, followed by isopropanol applied directly via a micro-dose type atomiser (or directly on the cloth) wiped immediately dry with a microfibre cloth is as near to ideal as I can find. Zeiss sell their own solvent that is even more effective, but I cannot find out what it is.MattMatt said:
I rather suspect, though (and am considering trying, but for waterproof scopes / binoculars only), that genuinely distilled water + mild soapless detergent applied with a soft brush then flushed with copious distilled water and followd by a wipe dry with a micro-fibre cloth would be even more effective because the basis of this method is the dissolving of any oil/grease film followed by 'mass dilution' with a residue-free solvent - and this is surely the best basis for any cleaning operation.
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There does not seem to be a consensus here. Why should breath be ok but lens cleaning fluid is not ok? I don't know about you all, but I have all kinds of nasty stuff in my mouth.
Also, some poeple have suggested cotton swabs. I would think cotton would be very abrasive on the lens, much more so than a lens cleaning cloth. Is cotton ok?
And what about lens brushes? They also seem harsher than cleaning cloths.
Also, some poeple have suggested cotton swabs. I would think cotton would be very abrasive on the lens, much more so than a lens cleaning cloth. Is cotton ok?
And what about lens brushes? They also seem harsher than cleaning cloths.
Gordon said:
scampo
Steve Campsall
Your breath is distilled water and is entirely pure (but saliva is not, of course)... I think that some non-specialist lens fluids might contain silicones to help prevent misting. That might be okay for spectacles, but not optics.
Absolute isopropanol, methanol or ethanol (if it is available) is surely the best - or distilled water.
Absolute isopropanol, methanol or ethanol (if it is available) is surely the best - or distilled water.
MattMatt said:
I would have thought that breath would be water vapour with lots of impurities. I'm sure an amateur astronomer would know for sure.
I would be careful with these microfibre cloths as they can pick up fine grit that will scratch the objective. I once once in Jessops on New Oxford Street and watched open mouthed as a salesman pulled a cloth from his pocket, breathed on a camera lens he was holding, and then wiped the lens with the cloth. I'm sure the coatings squealed audibly as the dirt from his pocket was smeared on the lens.
Cotton wool seems fine to me. After cleaning a lens it looks perfect when I examine it using glancing light. I have heard mention that it is not guaranteed free of grit, but I have not had problems. I always keep the bag well sealed, and use a fresh piece for every two or three wipes. I noticed that the bloke at Kay Optical used a cotton bud for removing a patch of dirt from a binocular lens.
My own method is to avoid constant cleaning of the glassware, just a soft blower brush when things get particularly bad...albeit that my glass rarely spends much time near salt water. I wonder what the main cause of damage to coatings/glass is? cleaning?
Watch out for certain insect repellant sprays (can't remember the precise chemical)..they can kill any coatings.
Watch out for certain insect repellant sprays (can't remember the precise chemical)..they can kill any coatings.
scampo said:
Well plenty of water vapour, various micro organisms including bacteria and fungi, and various chemicals dissolved therein including small concentrations of alcohol (?), and ammonia ...
Small particles of food dislodged from the teeth and mouth ... Have you never spoken with someone only to find your vision slowly disappearing as a layer of food particles slowly cover your eyeglasses?
Small particulates, perhaps inhaled as a result of being in a polluted environment ...
I expect some small drops of saliva will be in the exhaled aerosol, and that is slightly acidic ...
CO2 exhaled by us dissolves in water to give a weak acid which might attack glass ...
I've met one or two people whose breath could eat through steel never mind damage thin coatings.
So all in all breath might not be entirely benign ...
That's the one, thanks Sean. I know that product has eaten a number of camera lenses worldwide.dogfish said:
Jay Turberville
Well-known member
I'm in the infrequent cleaning camp. My understanding is that you can have quite a bit of dust accumulate and the effects are simply not visible. When I clean it is because there is either grit or a smudge on the surface.
I don't trust brushes. How do you ensure the brush is clean after a few uses?
I use a can of that compressed air before cleaning. I'm careful to test spray first to make sure it does not spray fluid and I keep the can vertical for that same reason. A hand blower of some sort is probably better. I'm told that spraying cold fluid on a lens objective could potentially crack the lens. I'm careful though, and this is my concession to laziness. I spray from at least 6 inches away and usually further to provide a somewhat gentle blast. I sometimes first use my ZeroStat anti-static gun to help neutralize static charges.
I then visually inspect to make sure there is no grit. If there is grit that air will not remove, then I'll try to gently lift it away with a dry cotton ball. If that does not work, then a cotton ball wet with isopropyl alcohol (the drugstore dilution) on the assumption that there is something that needs to be dissolved to break the adhesion.
I try to avoid cleaning in the field.
There is a ton of information on the web about cleaning optics. Lots of it from amateur astronomers.
I don't trust brushes. How do you ensure the brush is clean after a few uses?
I use a can of that compressed air before cleaning. I'm careful to test spray first to make sure it does not spray fluid and I keep the can vertical for that same reason. A hand blower of some sort is probably better. I'm told that spraying cold fluid on a lens objective could potentially crack the lens. I'm careful though, and this is my concession to laziness. I spray from at least 6 inches away and usually further to provide a somewhat gentle blast. I sometimes first use my ZeroStat anti-static gun to help neutralize static charges.
I then visually inspect to make sure there is no grit. If there is grit that air will not remove, then I'll try to gently lift it away with a dry cotton ball. If that does not work, then a cotton ball wet with isopropyl alcohol (the drugstore dilution) on the assumption that there is something that needs to be dissolved to break the adhesion.
I try to avoid cleaning in the field.
There is a ton of information on the web about cleaning optics. Lots of it from amateur astronomers.
