I have the new version R-28mm f2.8 ROM. I bought it in mint condition, though used, and very carefully checked that the glass was perfect. That was about a year ago. Yesterday on a job I noticed quite a lot of cleaning marks on the front and even rear elements, and I'm rather perplexed.

First, I don't clean the lenses very often, I have probably cleaned that one about four times in more than a year. When I do that I use a good cleaning solution with the kodak papers. The first thing I do is with the first tissue, saturate it with the cleaning solution and gently mop up anything on the element, namely dust or whatever. I usually do that twice to be sure all the dust is off--using pretty much no pressure. Then I take a couple dry tissues and slowly work off the solution.

Now, under a loupe, there are cleaning marks ALL OVER the front and rear elements. However on my R-35mm f2.0, which I have cleaned much more and is about 20 years old (also bought second hand) has almost no evidence of cleaning.

What is up with this? I thought the Leica coatings were supposed to be super-tough. I have really babied my glass and I'm rather ticked about it.

-- dave yoder (dave@daveyoder.com), May 31, 2002

Answers

Dave, Are you sure when you bought the lens that you thoroughly checked it over, as in a shop, because its darker, tiny scratches are usually harder to see. Did you check the lens with a torch as well? The best cleaning method I think is to not clean your lenses at all, but when you do, get a blower brush to remove as much surface rubbish and then continue with the method that you are currently using. Also bear in mind that the coatings are different for the various lenses, some may be softer than others.

-- Karl Yik (karl.yik@dk.com), May 31, 2002.

Try using a filter to protect the front element.

-- rob (rob@robertappleby.com), May 31, 2002.

Dave, I learned the hard way about cleaning solutions while trying to clean a B+W MRC Circ Polarizer. No fluid ever completely removed the finger prints that turned into 'smudges'. I called B+W in Bad Kreuznach and they suggested that I only should use alcohol and a microfibre cloth. Sure enough, that worked.

Based on that, the microfibre cloth is always my first, second and third choice. Only when I have stubborn smears will I dampen a small portion of the cloth. (The cloth is washable at 60° C and best to use a non-coloring, non-perfumed detergent.)

FYI Ethanol 70% (V/V) is my solution. I had to have it mixed at my local Apotheke (Pharmacy), but I think that you should be able to find one similar.

The other thing to consider is how much these small foggy, streaks imapct image quality. I do not know of any published reports, but I cannot image that by the time the light travels the distance to the film surface, and is then exposed, then developed, how much if any degradation there is in image quality. That will come as no reassurance to anybody at this forum, if you are like me, and simply enjoy having clean and mint instruments.

-- Reto (redcavereto@yahoo.com), May 31, 2002.

"They" say to breath on the lens, causing condensation to appear on the element then wipe with a micro fiber cloth. The best one seems to be, at least according to "them" again, a Microdear out of Japan.

Who are they anyway and what to they want?

Chad Hahn

-- Chad Hahn (thehahns@cornhusker.net), May 31, 2002.

Before you panic get some microfibre cloths and some household white vinegar cut 1:1 with water. Clean your lens with that and finish off with a moist breath and a final wipe with a clean mf cloth.

I have bought several lenses with marks and this has always removed the marks for me. I always use clean cloths for each stage and wash my cloths (with two complete rinse cycles) frequently.

Using vinegar as a regular lens cleaner is a bad idea as it is an dilute acid but once every couple of years to get off persistant marks is fine.

-- John Collier (jbcollier@shaw.ca), May 31, 2002.

And before you do what John suggested make sure you wash your hands thoroughly! The only time I have ever had that problem, is when the ROR or other solution was pulling the oils from my skin and transferring them to the lens. I use ROR on the corner of a micro- fiber and gently rub it on the lens, and then follow up with a clean dry portion of the micro-fiber. If I wash up first, nothing but crystal clear glass. If I don't wash my hands first, smears...

Cheers,

-- Jack Flesher (jbflesher@msn.com), May 31, 2002.

I've always been told never to use tissue on lenses. I've also always been told to let actual cleaning of lenses to pros. But my pro uses tissue damped in methanol, not ethanol. Go figure. But he never actually rubs the lens with it. In the mean time, UV filters and great care for the back element (put the cap back on as soon as you've dismounted the lens, for one) are recommended. Now, I do use a lenspen from time to time on filters, and once in a while on lenses, with no apparent ill effect. But microfibre cloth? I don't know...

-- Olivier (olreiche@videotron.ca), May 31, 2002.

Another good tip is to store your cleaning cloth in a 35mm film canister and to shake the cloth violently in the air before you use it. This is called the 'Lens clean no stratch ritual' :)

-- Karl Yik (karl.yik@dk.com), May 31, 2002.

Dave, Microfiber cloths are the only way to go...after using a blower with a camel's hair brust to remove loose particles. Leica gives away microfiber cloths at their sales events...otherwise they are readily avaliable at any camers shop. Nonetheless, BE GENTLE. Good shoot

-- George L. Doolittle (geodoolitt@aol.com), May 31, 2002.

My experience is that Kodak lens tissue can scratch lenses. As odd as that sounds, I never use lens tissue to clean lenses, only micro- fiber cloth.

-- Andrew Schank (aschank@flash.net), May 31, 2002.

you started out wet!!! you should start out with a camel hair brush and compressed air. thatll remove the nappy abrasives b4 pushing them around on your elements with a sopping paper. then, use a soft cotton lens coth and a touch of ROR cleaning fluid. then, lightly buff any streaks left with a dry portion of the cloth. works for me...

-- James (snodoggydogg@hotmail.com), May 31, 2002.

Dave. Either the lens already had cleaning marks and you just didn't notice (Believe me, this can happen, it has happened to me!) or else you put them there. First of all, dust and any particulate materials should FIRST be removed with a camel's hair brush or (carefully) with compressed air (use only if needed). Only then should you wipe the lens surface. And you should only use microfiber cloth, nothing else. In fact, Leica provided a microfiber cloth in the box with my M7. That's a pretty good indication of how they think a lens should be cleaned.

Finally, as I've said before, "it is better to keep your lens clean than to keep cleaning your lens." That's why I would use UVa filters on all expensive lenses regardless of what any one else says about potential image degradation - that just won't happen. I learned all of those things from the school of experience, which is usually a very reliable teacher.

-- Eliot (erosen@lij.edu), May 31, 2002.

Also bear this in mind: while it depends on the focal length, aperture setting, and severity of the marks, much of the coating and glass damage that we obsess over is NOT really going to affect on-film performance. I used to have a 135mm f2.8 Nikkor with a just atrocious-looking front element, and it was a very sharp, contrasty, flare-free lens. Wish I still had it.

Other things equal, though, I think coating and glass defects probably have more effect (if any) on the image when the lens is wider and used at smaller apertures. e.g., a 180mm f2.8 with coating marks will probably work just as well as a perfect one, while a 21mm f4 may show some image degradation.

-- Douglas Kinnear (douglas.kinnear@colostate.edu), May 31, 2002.

Every cleaning cloth I've seen was polyester/blend, and Leica in my Elmar-M instruction booklet recommends cotton hankierchiefs with breath moisture. I just use polyester/cotton handies throughly washed.

-- Glenn Travis (leicaddict@hotmail.com), May 31, 2002.

I first use a blower, then ROR and clean 100% cotton (cut from old BVD's) followed by a breath and more clean cotton. Never scrub with pressure, always with as light a touch as possible. And I use B+W MRC UV filters on my lenses 100% of the time, even if adding another filter like a polarizer (except wide angle lenses where this would cause vignetting). Rear elements are exposed to air as quickly and infrequently as possible. The only lens I've ever gotten wipe marks on was a 180/3.4APO-Telyt which suffers in performance with any kind of filter attached. Leica coatings are strong. But sand and grit are stronger.

-- Jay (infinitydt@aol.com), May 31, 2002.

There's more to drinking a fine Single Malt Scotch than the mere enjoyment of its consumption. It renders ones breath perfect for the cleansing of ones Leica lenses when used with a soft cotton cloth!

-- Tony Rowlett (rowlett@mail.com), May 31, 2002.

Here here!

-- Charles (cbarcellona@telocity.com), May 31, 2002.

For the cheaper Russian lenses; Beer breath works fine...

-- Kelly Flanigan (Zorki3c@netscape.net), May 31, 2002.

Okay, Kelly, point noted.

Glenn: The American Cinematographer Manual, Seventh Edition, Recommends fogging the lens with breath before wiping. So, you're in good company.

-- Bob Fleischman (RFXMAIL@prodigy.net), May 31, 2002.

BOB; In college I would read the small black American Cinematographer Manual during lunch on Sundays at out Cafeteria........I would read it cover to cover religiously....It is a great book...My prime movie camera was a Beaulieu MR-8 reflex 8mm camera with variable shutter and frame rates.....My friend had a 16mm Bolex..

The next semster I ordered a cameramans manual that showed how to load all the Hollywood 16mm. 35mm & 70mm movie cameras..it was a dark green covered book...When I was reading it religiously one sunday in the cafeteria; and old lady worker came to my table to see what the new Bible edition I was reading...............Kelly

-- Kelly Flanigan (zorki3c@netscape.net), May 31, 2002.