Lens Tube Cleaning for ETC Source 4 ERS

DO NOT use ammonia based cleaning products, like Windex, it will severely degrade the optical coating on the lenses.

Vacuum with a dusting attachment first, to remove as much dust as possible before I go in with anything liquid.

Use a mixture of isopropyl alcohol and distilled water. 50/50 works, more alcohol if there is a residue which is hard to remove. Tou can use straight isopropyl alcohol, however, it may dry too quickly and leave streaks.

Use a soft cloth for cleaning, like T-Shirt material, NEVER any paper products, as paper is abrasive. Move to a clean section of cloth for each half to avoid smearing around what you have previously removed while cleaning.

Use a microfiber cloth to polish the lenses. The goal is to have the lens sparkle with no smears or smudges.

Standard 19º, 26º and 50º, all but 36º, can be cleaned without disassembly, however, you will need to crack the 36º open. If you have EDLT lenses, these will need to be opened as well.

Depending on the age of your lens tubes, the four Phillips head screws holding the lens halves together may have Ny-lok nuts on the other side.

Be mindful of the Color Frame Retainer Clip, it has a spring that will try to escape when you separate the two halves..

Since the lens tube is apart, I find it easier to remove the lens cushions from the lens for through cleaning.

The lens cushions can be tricky to reinstall. When reassembling, place the lens half with three cushions on a flat surface, insert the three or six cushions and lenses, paying attention to the orientation of the dots on the lenses, they face the color frame side of the lens.

Install the other four cushions in the other lens half, insert the CF retainer clip and spring, then carefully work it all back together.

Once everything is seated correctly, install screws and nuts if applicable