Just Cleaned my Eyepieces for the First Time...

[pgc hunter]

... and why did I not do this sooner! Wow, what a difference! My eyepiece lenses are now practically showroom quality I had my current set for a few years and in that time, I never actually cleaned them, I was too chicken. But as it turned out it's a simple process that I need not feared.

I started reading posts about eyepiece cleaning on the forums, picking ideas and technique. So I set up with a box of kleenex, Isopropyl Alcohol and some Q-tips and spent the last 2 or so hours this overcast evening cleaning and ended up with a set of gleaming eyepieces! Forecast is ofcourse wall to wall clouds

That's one more primal fear disposed off

[floyd_2 (Dean)]

I remember back 20 or 30 years ago wanting to get my hands on pure isopropyl alcohol to clean eyepieces - what a drama that was. I finally found a chemist who gave me a large dark glass bottle of it. These days you can get the stuff just about anywhere!

[leon]

For some reason people are so afraid of cleaning Lenses, EP's and other optical surfaces.
These surfaces are tougher than the manufacturers make out.
I still do and always have cleaned my Canon 5D sensor filter, and other optical lenses with a good quality lens pen, and it comes up a treat every time.


Leon

[Rick Parrott]

The Lens pens are really good! Use them on my eyepieces, binoculars and even my iPhone camera lens!

[Don Pensack]

Lens pens sound like a good idea until you look at how they work:
there is supposed to be a fine black powder in the reservoir into which the fuzzy rubber pad dips. This fine black powder is supposed to both absorb water and oils and also to allow the fuzzy rubber pad to burnish the surface of the lens.

Alas, this will leave a small residue of powder on the lens that simply does not blow off (look with a loupe if you don't believe me), and it runs a high risk of scratching the optical surface. On top of that (as if that weren't enough), the rubber pad can only be clean once--after that it contains some residue of the contaminants you cleaned off the lens.

It's a bad, and poorly-conceived, method of cleaning a lens.

What is preferable? Well, clean cotton Q-Tips with a cleaning fluid of some sort for one. Or micro-fiber cloths (fresh ones, unused) with a cleaning fluid for another.

First, blow off as much of the dust and solid material on the lens as possible. Do not used canned air, which can blow liquids, but use a blower bulb of some sort. Do not use a brush because a brush, like a lens pen, can only be clean once, and, thereafter, merely smears stuff around.

The wet cleaning device makes a pass or two. The dry cleaning device (Q-tip or cloth) makes a second pass to mop up the fluid and debris from the first pass. The third pass cleans any streaks left by the first two.

If the eyepiece was really dirty, or streaked with mascara, try two cleanings with a wet cleaning device before any dry surface touches the lens.

Cleaning for eyepieces not too dirty can be Nikon or Kodak lens cleaning fluid, ROR, isopropyl alcohol. If the eyepiece is much dirtier, remove the rubber eyecup, make certain there are NO plastic parts near the eyepiece, and use pure acetone on a Q-Tip. It will dissolve stuff the other cleaners won't, but be sure to use it in a well-ventilated area.

It goes without saying that isopropyl alcohol or acetone must be pure and without any additives at all (other than water in the mix), so no "rubbing alcohol" or "fingernail polish remover".

There are stronger solvents, but they are usually unnecessary to use on eyepieces less than a hundred years old (and covered with dirt and mildew).

[MortonH]

Even just breathing on the glass and wiping gently with a Q-tip can make a huge difference (use the blower first, of course).