Rocky Mountain Instrument Co.

Tech Notes » Care and Cleaning



All high-quality optics and coatings are delicate devices that are subject to damage if not handled carefully. Below are the recommended common practices for care and cleaning of your optics:

1) Do not touch the effective optical surface with your bare hands. Oil from one's fingers produces stains that are difficult to clean.

2) Do not place any optical surfaces on any hard surfaces such as a work table. Doing so can scratch or otherwise damage the optical surface.

3) To remove dust, canned dusters, bulb-type blowers and anti-static brushes can be used. Dust can be tightly bound by static electricity so it is advised to clean with alcohol or acetone in addition to blowing.

4) To remove any surface contaminants, we recommend using a soft, lint-free lens cleaning paper, soft cotton ball, or cloth. It is advisable to wet these with alcohol or acetone (both evaporate quickly) and gently rub or drag from one surface of the optics to the other. It may be necessary to repeat this process, using a new tissue each time.

Another common final cleaning practice is to put a piece of thin lens cleaning paper over the surface of the optics, wet the far side (about 1/3 of the length or diameter) with alcohol and gently pull across the optic. By the time the tissue is off the surface, alcohol should have evaporated, leaving no stains. Again, you may have to repeat this process; multiple cleanings of this sort will not damage the coating.


Immersion Cleaning

Delicate optics with soft coatings (including bare metal coatings) are best cleaned using the immersion method. Prepare four Petri dishes with a soap solution (neutral soap, 1%), distilled water, alcohol, and acetone. Line the bottom of each dish with a piece of lens cleaning paper to avoid damaging the optic. Immerse the optic in the soap solution and gently agitate. Repeat for each of the next three dishes and then blow dry. Repeat as necesarry, but be sure to replace the solution after eah round to avoid re-contamination. 

Commonly Used Equipment:

• Lens cleaning paper*
• Latex finger cots
• Cleaning swabs
• Canned duster
• Bulb-type blower
• Anti-static brush
• Alcohol
• Acetone

*RMI supplies the recommended lens cleaning paper. Contact us for more info or to order.