What is the proper/recommended way to clean a lens?

[Frank Raia]

What is the recommended way to clean lenses to avoid scratches? What cleaning solutions and cloths do you use? What methods and cleaning supplies are bad, and why?

[Ryan Gallagher]

My cursory knowledge/preferences, this is one of those topics you’ll find lots of answers to depending on the individual.

As a general rule, if it can be cleaned without contact do it that way, air bulb or duster (careful not to spray the liquid by accident). This is more doable in routine cleaning.

Also avoid alcohol/acetone and commercial glass cleaning products like the plague. Some have ammonia in them too.

If it is beyond a simple dusting, the same principles apply as with camera lenses/filters and other optics. Either distilled water only, or specific lens cleaning solutions and gentle use of disposable lens cleaning clothes (changing them frequently).

Rubbing, even with correct cloth is considered bad form as you can drag particles and cause scratches, but lots of advice speaks of small circular motion, the key is almost zero pressure and changing cloth constantly. Dab method or soaking and lifting a cloth is preferred, especially in the initial dirtier passes.

”Fogging” a lens with your breath is one way to get distilled water, but use with caution, can always spittle bacteria onto it too!

I have found even with some cleaning solutions you still need a distilled water rinse at the end to avoid streaking.

If the optics are of extremely high value to you and you are very risk averse, there are “paint and peel” products specifically for scientific optics, but you’d want to check with manufacturer about compatibility with the various lens coatings.

Our booth has bulbs, brushes, and dusters. I can share what liquids and cloth products next time I’m there. We are in need of the paint and peel stuff for our 1st surface optical mirrors “soon”, unless we dismount them for submersion cleaning, which I’d like to avoid.

[Frank Raia]

Thank you Ryan, I have clothes in the picture. I do not have any cleaning solution. I ask the question because even with cloth and solution I have seen scratching happen, as you mentioned. I will have to find out about the "paint & pull". I definitely would like to know what products you use. IMG_20250913_110946.jpg

[Ryan Gallagher]

be careful with kimwipes... they can be fairly abrasive (especially if not fully wetted).... they are marketed as lint free... but that does not mean optics suitable. Think of them like lint free kleenex or paper towels for a clean-room environment, for other cleaning purposes... but not suitable for lenses/optics.

A google AI result on the topic:

Yes, Kimwipes can be dangerous for cleaning lenses because they can scratch the lens surface, especially delicate camera or microscope optics, by containing natural crystals from plant cells that act as abrasives. While Kimwipes are designed to be low-lint and are used for other delicate lab equipment, specialized, soft lens paper or microfiber cloths are specifically made to clean optical surfaces without causing damage.
Why Kimwipes are Risky

• Abrasive Particles:
  Plant-based materials like those used in Kimwipes can contain microscopic crystals from plant cells that are abrasive and can scratch glass and coatings, according to this Google Groups thread.
• Pressure:
  Using a dry Kimwipe with pressure, or with debris already on the lens, can exacerbate the risk of scratching.
• Lens Coatings:
  The abrasive nature of Kimwipes can damage the delicate coatings on camera and microscope lenses.

I also picked up a bunch before I knew better... so don't feel bad. Thankfully cleaned old junk lenses we do not use first and decided they were not the ticket.

[Frank Raia]

Ah, thank you for the insight! No kimtech !!! Would photography lens cloths work?

If Brad Miller is listening... Are the kimtech cloths in the picture suitable for hand cleaning film with film guard?

[Ryan Gallagher]

Ah, thank you for the insight! No kimtech !!! Would photography lens cloths work?

If Brad Miller is listening... Are the kimtech cloths in the picture suitable for hand cleaning film with film guard?

I would speculate that if they are too abrasive for lenses, they are too abrasive for film emulsion too. But I am eager to be corrected if they are suitable for that purpose. I got plenty of them.

For spot cleaning film stock during inspection we use high quality q-tips or cosmetic cotton pads. But they are kinda annoying in that their fibers will get caught and can get left behind.

Disposable photography lens cloths are what we use when wet cleaning optics. I would avoid re-usable dry microfiber type ones... unless you plan to only use them once. They will trap dibris and be a scratch risk on subsequent uses. Wet is always better if you have to touch the lens during cleaning.

Will share products when I get to work tonight.

[Ryan Gallagher]

The marketing confusion with Kimwipes is that they are suitable for uncoated optics and substrates, and get used in labs for that purpose all the time... it's the more delicate coatings they are incompatible with.

[Ryan Gallagher]

Here is my booth supplies:
- Dry Tiffen lens “paper” (extremely thin stuff)
- pre wetted individual Zeiss lens cleaning pads
- Tiffen lens cleaning fluid
- air bulb / canned air
- lens cleaning kit brush

Not all are needed for routine cleaning.

IMG_6539.jpg

[Christos Gartaganis]

I have been using the Rosco Film Cleaner for many years and am satisfied with its performance. It is safe for coated lenses and teams up perfectly with the Kinetronics Tiger Cloth. I prefer the spray bottle version because it allows precise control over the amount of liquid applied to the cleaning cloth.

[Chris Wehrman]

I agree with Ryan's advice. Use air first, then a gentle "blotting" with dampened tissue. New tissues often. Then gentle circular wiping with extremely low pressure. Wipe till clean and dry.

Ryan, do you use the zeiss wipes on your lenses often? Dose anyone know if they are safe for projection lenses?

I noticed that film-tech is now selling lense cleaning fluid. Has anyone tried it yet?

I find, if you run film-guard, you don't have to clean your lenses very often at all.

I still have a big bottle of rosco fluid as well as lense tissue that will last me a very long time. When that runs out I'll move to the film-tech brand.

[Ryan Gallagher]

I agree with Ryan's advice. Use air first, then a gentle "blotting" with dampened tissue. New tissues often. Then gentle circular wiping with extremely low pressure. Wipe till clean and dry.

Ryan, do you use the zeiss wipes on your lenses often? Dose anyone know if they are safe for projection lenses?

To be honest those individual zeiss wipes pre-existed my time, but our TD bought another giant box, they seem potentially less gentle than the Tiffen papers, so I’ve stuck with those. They run haze in our building so wet cleaning is sometimes required, maybe only once a year though.

i cannot testify if they are totally safe, but as they are also for multi-coated camera lenses and glasses I expect they are fine. The trick I expect is being willing to use more than one per cleaning (or being careful not to re-use the same section of the wipe.

[Chris Wehrman]

As long as you have "the real stuff" I'd hide the box of Zeiss. They work wonders for my glasses, but like you say, they seem a bit rough for projection lenses.

Haze, that's a different story. Hope it stays out of the booth!

[Ryan Gallagher]

As long as you have "the real stuff" I'd hide the box of Zeiss. They work wonders for my glasses, but like you say, they seem a bit rough for projection lenses.

Haze, that's a different story. Hope it stays out of the booth!

A little reading reveals the Zeiss pre-moistened wipes are in fact non-abrasive fibers (despite feeling coarser to the touch) , but the catch is they contain alcohol, so certainly not a first choice for wet cleaning where worries about breaking down the coatings exist.

[Frank Raia]

I found this film tech discussion

https://www.film-tech.com/ubb/f1/t008858.html

[Frank Raia]

Roscoe lens cleaner is listed as ethanol Rosco_Lens_Cleaner_SDS_020323_V3.pdf

So that is an alcohol also. So I guess that's a no go?

Formula mc, has alcohol.
The Formula MC lens cleaner contains a blend of ingredients designed for effective cleaning without damaging lens coatings. The primary components include:

• 100% distilled water: Acts as the main solvent to dissolve dirt and oils.
• Isopropyl alcohol: A mild solvent that aids in removing stubborn residues.
• Surfactants: Help break down grease and oils for better cleaning.
  This formulation is specifically designed to clean multi-coated filters and lenses without leaving a residue