Telescope Reviews: How often do you clean your bino lenses?

Jeronimo,

First I want to apologize to you and to everyone else for the length of this reply: it's long, and hopefully not too boring!

This is an interesting topic (as is obvious by the number of replies!). It is one that never concerned me until last year. I've owned binoculars since 1969. I recall that I hardly ever cleaned any of them (optics). Over the past few years I've used my 1984-vintage Celestron Nova 10x50s quite extensively, mostly "out in the field" (I do a lot of railroad photography). I haven't exactly treated them with "kid gloves". I almost never use the lens caps (too inconvenient and too much risk of losing them). So yes, they get dirty. I've frequently resorted to the hot-breath blow/wipe the lenses with my shirt, etc. Yet I've apparently done no damage to the lenses. These binos are built like the proverbial tank. After discovering CN in late 2006 and reading up on binos I realized how dumb and potentially dangerous my lens-cleaning process was. Now I'm much more careful with the Celestrons.

I clean them fairly frequently, with my camera shop's lens fluid and Kodak lens-cleaning paper. These do a fine job. I first take one piece of lens paper, wet it with a few drops of the fluid, then clean each lens with a circular motion, starting from the center and working outward. Next I take a dry piece of lens paper, blow warm air on the lens, and repeat the circular cleaning motion. The only glitch is that this doesn't get the (now dried) fluid off the lens. So I repeat with a third lens tissue - blowing warm air and the circular wiping. This results in a nicely cleaned lens. I use the same equipment and technique on my camera lenses, producing the same result. As far as I can tell there is no damage to any of these lenses.

However, this was/is not the case with my Vixen ARK 16x80 binos. I bought these in early 2007, and they're delightful. But last Summer I noticed that, when viewing Jupiter, the image seemed a bit "smeared", and there was an increased amount of CA - twice what I'd seen when looking a Jupiter the previous Summer. My conclusion was that the lenses had gotten dirty - though I had no idea how. I am a smoker, and even though I keep the Vixens in their case in my bedroom (wherein I never smoke) and treat them like gold, I assumed that cigarette residue had nonetheless found its way into the case an onto the lenses (even though they were capped).

So I decided that they definitely needed a cleaning. As I described, my standard cleaning process works fine on my Celestron binos and my camera lenses. Not so with the Vixen lenses[!]. For the life of me I could not figure out why. What would happen was that when I did the warm-air blow/dry-tissue phase the lenses would begin to look "greasy". Something seemed to be putting some kind of residue on them. I could be wrong, but I suspected that it was skin oil from my finger "bleeding" through the lens tissue. Why wan't this occurring on my other equipment?

I tried twice to clean the Vixens and then gave up, not wanting to increase the risk of damaging the optical surfaces. Later it dawned on me (duh) that one thing I didn't own was a lens-cleaning cloth. I bought one from my camera shop, pulled out the Vixens, and did my usual cleaning routine on them, this time finishing up with the lens cloth. Suddenly the lenses once again appeared pristine, essentially the same as brand new. I was very pleased by this, and even more relieved. I had the Vixens out one night this August, and noticed a bit of CA on Jupiter, but different from what I'd seen previously (a kind of orange-ish fringe at the 4-5 o'clock and 7-8 o'clock positions). My conclusion was that my cleaning had really helped but that the lenses still weren't completely clean. Hmm. Yet when I swung the Vixens over about 30 degrees to view the just-past-half-full Moon I was very impressed. "Stunned" may be too strong of a word, but the view definitely gave me pause. Now, 16x isn't a heck of a lot, but I could clearly see the mountains, "seas", and craters. And I mean craters! A multitude of them. And absolutely no CA visible anywhere. The best word I can think of to describe the view is "stark". And "razor sharp". The detail was simply amazing. It was the most rewarding view of Luna I've ever had in my life; not just through the Vixens alone. This was when I took the seeing conditions much more into context as far as the view of Jupiter was concerned. I agree with many here on this forum: Jupiter is one of the most difficult objects to view satisfactorily. One reason (probably the main one) is that it is so darned bright! I can understand why folks recommend filters.

So, this is my detailed (probably too much) commentary on binocular optics cleaning. To me the most important event in years optics-wise was the purchase of the lens-cleaning cloth. A minor miracle, IMO.

Yet I still cannot fathom why my standard lens-cleaning process works fine for my other equipment but not for the Vixens.

Any ideas/suggestions are greatly appreciated.

All the best,

Mike Rapchak Jr.