I have recently purchased a cleaning solution for precision optics which has the following ingredients (amounts were not specified):

  • Ethyl Alcohol
  • Methylethylketon
  • Aqua
  • Diethyl Ether
  • Isopropyl

Typically reagent grade isopropyl alcohol alone is used for cleaning optical elements. So, does the mixture above provide any advantages over using pure isopropyl? (Possible advantages may include a faster dry time, better removal of oils/smudges, and less toxicity)

Any explanations would be greatly appreciated.


1 Answer 1


It might possibly be intended to dissolve an adherent organic film, such as that left by evaporation of plasticizers from foam packaging.

However, it also might well partially dissolve paints and cements used in the lens assembly, leaving yet harder-to-remove dirt on the lens. Unless you have a specific need for those solvents, use distilled water and/or isopropanol, according to B&H.

  • $\begingroup$ According to the manufacturer, the solution is meant to be non-invasive to the thin film coatings on the lenses, so it is suitable for camera lenses as well as laser optics. The performance appears to be similar to pure Isopropyl. So, I wasn't sure if the admixtures really offer any benefits... $\endgroup$
    – Merin
    Commented Oct 3, 2019 at 22:20
  • $\begingroup$ Butanone, also known as methyl ethyl ketone (MEK) (see Wikipedia) is an effective solvent for paints and varnishes. If a bit got on a painted ring around an optical element, it would deposit a film of paint on the edges of the lens. This might not be a problem with black anodized lens rings, but why take a chance? $\endgroup$ Commented Oct 4, 2019 at 4:13
  • $\begingroup$ Thank you so much for the explanation. I see. Do you know of any advantages or disadvantages associated with the other two ingredients (namely, ether and ethyl alcohol)? $\endgroup$
    – Merin
    Commented Oct 4, 2019 at 5:54
  • $\begingroup$ About the same as butanone, though less likely to dissolve paint or cement. $\endgroup$ Commented Oct 6, 2019 at 0:30

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