Wednesday, July 28, 2010

Cleaning Precision Optics

You probably already know that UniqueTek has a great selection of shooting and reloading supplies. But, what you may not know is that their site is a great resource for shooting and reloading info.

When you visit the
UniqueTek site, go to their "Free Tips Files" page. Simply enter your email address and they will send you their current "tip" file. You can also browse other tip files. If you see one you want, send them an email and they will send it your way. In other words, they only send you the info you want! If you email volume is like mine, you will appreciate this!

To give you an example of the quality and detail of their tip files, check out the following. This is their "Cleaning Precision Optics" file. Great info!

Cleaning a lens, whether it is eyeglasses, camera, binoculars or a rifle or pistol scope, is a delicate matter. It is VERY easy to do more harm than good. But if you follow a few simple rules, and use the right tools, your optics can be maintained in perfect condition.

The “Rules” for Lens Cleaning

Rule #1: Don’t get your lenses dirty!

It seems like a snide thing to say, but it is true. If you protect your lenses from getting dirty, you won’t have to clean them. And lens cleaning often causes more damage than anything else you do to your optics. In fact, this is such an important point, it should be the first 3 Rules!

Rule #2: Less is more.

When you do need to clean your lens, less is more. The less cleaning you do, the less likely you are going to cause some kind of damage. So, if it only needs to have a few dust articles blown off, do only that.

Rule #3: Use only specialized lens-cleaning products and use them only for lens cleaning.

There are many specialty lens-cleaning products on the market. The cost is negligible compared to the cost of replacing a scratched lens. Keep them all together in a small zipper lock bag or similar dustproof container and use them only for cleaning your lenses.

use household products for lens cleaning! It is just begging for problems. Window cleaner (e.g. Windex) has very strong chemicals that can damage or even remove certain lens coatings. Never use Kleenex, toilet tissue, paper towels, a handkerchief, the tail of your shirt, etc. to clean a lens as they can scratch or add contaminants.

Rule #4: Clean a Dirty Lens ASAP!

When anything does get on a lens, you should clean it off immediately. This is especially true with liquids as, once they have dried, any residues they left behind will be more difficult to remove. The only exception to this rule is if cleaning the lens immediately could potentially expose the lens to more contamination or damage. If you are in the middle of a dust storm, you better wait and clean the lens later.

Keeping Lenses Clean

OK. So, in accordance the Rule #1, just what do you need to do the keep your lenses clean? Well, that depends on what the lens is on.

Camera Lenses:
Of course you should always keep the lens cap on any time you are not actually taking a picture. But, as an extra layer of protection, you should screw on a 1A Skylight filter. They are only $10 to $30, depending on size, and are cheap insurance. Just buy one at the same time you buy the lens, install it immediately (before the lens ever has a chance to get dirty) and leave it on for the life of the lens. Any cleaning will be done to the filter and you may never have to clean the actual camera lens. And, if you ever do scratch the filter, it is easily (and more importantly) cheaply replaced.

A collapsible rubber sunshade also works well on a rainy day to minimize the number or raindrops that hit the lens. Plus it adds a bit of extra protection against accidental impacts to the lens.

Binoculars and Scopes:
Keep the lens caps on any time you are not actually using binoculars and scopes. Some come with flip-up lens covers that flick open in an instant and close just as easily. The best thing about these is that they can’t be dropped in the dirt or lost. If your binoculars or scope didn’t come with these, you can also buy them separately. Earlier versions were just black plastic but new versions are available with polarizing and/or contrast enhancing filters, so you get the equivalent effect of the 1A Skylight filter mentioned above. You don’t even have to flip them open to use the scope so you won’t miss that quick shot. Plus, if the filter gets dusty or raindrops on it, you can just flip it up in an instant. These run about $10 a set so, once again, are cheap insurance.

Not much can be done to prevent eyeglasses from getting dirty as you are wearing them or handling them constantly and will need to clean them much more frequently than any other type of lenses. If you have the option for “hard coat” when they are being made, it will help them survive the frequent cleanings.

Tools of the Trade

OK. So you reach a point where you absolutely must clean a lens. First you need the correct tools for the job.

Lens Blower:
A lens blower is the best way to remove loose dust particles. It is the first, and often the only step you need to clean a lens. I find the small blowers with a brush attached are too small to make much of a puff. Larger blowers work much better (e.g. the Promaster Hurricane Blower, about $8.00). Give it a few squeezes each time
before you use it to ensure there are no particles inside. Lastly, keep in mind that the rubber can dry up with age and eventually start releasing particles, so plan on replacing it every year or so.

An ear syringe works great. They are inexpensive, come is several sizes, and available at any drug store. If nothing else, they make a great emergency backup of you loose your Hurricane Blower. Before you use it for the first time, squeeze it repeatedly to eject any particles that may be inside. There is often a powder inside that helped release it from the mold when it was manufactured. This can also be true for puffers made specifically for cameras, so don’t think you are safe just because it says “for camera lenses” on the package.

Canned Air:
Instead of a lens blower, you can use one of the many “canned air” products. But you must be very careful! If any comes out as a liquid the extreme cold can instantly damage lens coatings. To prevent this from happening, always keep the can upright and use only short puffs, never a long blast.

You may want to also keep a lens blower in your kit, as it will never run out just when you need it the most.

Never blow particles off with your mouth!
Even if you can’t see it, you will always blow micro-droplets of saliva onto the lens. The chemicals naturally in your saliva can do nasty things to lens coatings.

Lens Brush:
Lens brushes are simple camel hair or synthetic fiber brushes. The handiest type is called a “lipstick” brush because the brush can be retracted into the housing and a cap placed over it. The cap protects the brush from getting dirty or the bristles getting bent. My favorite is the Ultra Brush, which has synthetic bristles and runs about $6.

Lens-Cleaning Solution:
There are many quality lens-cleaning solutions available. The instruction manual that came with the optics will usually tell you the manufacturer’s recommendation. If there is no recommendation, or if that product is not readily available, any lens-cleaning solution manufactured by a reputable company should fit the ticket. Just make sure to read the ingredients list and avoid any lens-cleaning solutions that contain Ammonia or Silicones (an anti-fog). The best lens cleaning solution I have found is Ultra Clarity® by Nanofilm, Inc.

Never exhale on a lens to fog it over for cleaning!
The chemicals naturally in your exhaled breath can do nasty things to lens coatings.

One-shot Lens Wipes:
These are individually packaged, disposable lens wipes, pre-saturated with lens-cleaning solution and packaged in a tear-open foil pack. The big advantage is that they are much more compact than carrying a bottle of lens-cleaning solution and microfiber cloth. Let’s face it, there are times when it just isn’t convenient to carry your full lens-cleaning kit, like when you are out hunting for the day. Tuck a few of these in your pocket and you can survive for the day. But on a rainy day, you should still keep a microfiber cloth on hand just to soak up raindrops.

Lens wipes are handy, especially for eyeglasses, but I recommend that you use the lens-cleaning solution and microfiber cloth for serious cleaning and the lens wipes just for a “quickie” in the field. Also, keep in mind that you should still try to blow off or brush off any particles before using any type of lens wipe.

You can use a disposable lens wipe to remove dust particles by rolling it into a wand or twisting it up into a flower shape and using just the edge of the material to gently sweep any particles off the lens. Then use another disposable lens wipe for final cleaning.

Most manufacturers of lens-cleaning solutions (including Nanofilm) now offer these individual lens wipes.

Lens-Cleaning Cloth:
In the old days, the only choices in this department were a high-quality cotton cloth (which often came with the binoculars or scope), or lens tissue. The new “microfiber” lens cloths are now the best way to go. They are often included with the bottle of lens-cleaning solution. But once it gets too dirty, don’t bother trying to wash it. Just toss it out and get a new one. Again, this may seem wasteful and expensive, but it is a whole lot cheaper than replacing scratched optics. You may be able to get a deal from the seller if you buy several at a time.

Carry more than one microfiber cloth. I’ve dropped mine on the ground more times than I care to admit, so a spare is handy.

On rainy days, you may want to keep an extra microfiber cloth just for drying water off the lens and reserve the other just for use with lens cleaning solution.

use paper towels, napkins, toilet tissue or facial tissue as they are likely to scratch the lens.

Cotton Swabs:
A small supply of cotton swabs (e.g. the proverbial Q-Tip swab) is very handy.
Don’t ever use one directly on a lens, but you can use them to clean areas adjacent to the lens
rather than get your lens cloth dirty.


If you have fat fingers, you can wrap the tip of a cotton swab in a microfiber cloth to reach into small spots that are difficult to get to with a finger.

There are ultra-clean, scratch free synthetic tipped swabs that can be used directly on lenses. They tend to be expensive and difficult to find, but can be a valuable tool. Make absolutely certain that they are rated for use on lenses and compatible with lens cleaning solutions.

This is the one tip that you never hear mentioned in any discussion of lens cleaning. Often we are out and about when we need to clean a lens and our hands are covered with particles and, as always, coated with natural skin oils. The last thing you want to do is accidentally touch a lens with your finger while cleaning. If you are wearing gloves, this can’t happen and you will also be less likely to transfer particles from your hands to the lens. Any disposable latex or nitrile glove will work, but make absolutely certain you are buying “powder free” gloves. I don’t recommend vinyl or poly gloves as they are slippery and tend to hold a static charge that attracts particles. My favorite is the nitrile gloves. Keep several pairs in your lens cleaning kit and dispose of used gloves after EVERY cleaning session.

A few years ago, a new lens-cleaning product hit the market … the “LensPen”. The LensPen contains very fine particles of activated carbon. The activated carbon is capable of adsorbing fingerprints and other oily substances from the lens surface. You must still be diligent about first removing any particles that might scratch the lens before using a Lens Pen. In fact, use of a lens brush is recommended in the LensPen instructions.

Due to the cupped shape of the LensPen tip, it works best on convex lens surfaces like those commonly found on scopes, binoculars, cameras and the front face of eyeglass lenses. It doesn’t work quite so well on flat or concave lenses (such as the backside of eyeglass lenses). In the case of eyeglasses, this is not only because of the shape of the LensPen tip, but also because the back side of eyeglasses get very dirty, very quickly. You may get better results, faster with conventional lens cleaning techniques (e.g. the disposable lens towelettes described earlier). Finally, the LensPen comes in two different sizes for different diameter lenses. So you may need to carry two of them to cover the various lens sizes of your optics.

At the 2009 Shot Show, LensPen was demonstrating new products designed for cleaning small flat LCD displays (e.g. digital camera view screens, cell phones and PDAs), large CRT and LCD displays (e.g. desktop and laptop computers) and even the CCD and CMOS sensors inside digital cameras. Definitely worth taking a look at!

Cleaning the Lens

Step 1:
Blow off any particles (or water droplets) with the blower or canned air. If you use canned air, make sure to hold the can upright and only use short puffs

Step 2:
Use a lens brush to gently dislodge any particles that didn’t come off with the blower. When using the brush, start in the center of the lens and work in a spiral pattern toward the edge. DON’T use the brush if the lens is still wet, as you will just contaminate the brush.

Step 3:
Blow off the loosened particles with the blower or canned air.

Use the blower or canned air to blow particles off the lipstick brush before putting it away.

Step 4:
Use a few drops of lens cleaning solution on a microfiber cloth. Wipe the lens
gently. You don’t need to scrub hard. Work from the center of the lens to the edge.

If you are removing a fingerprint or other localized spot of contamination, use an isolated corner of the microfiber cloth just for that spot, and then switch to a clean part of the cloth to clean the rest of the lens. This way you are less likely to spread the contamination around the lens.

Don’t apply lens-cleaning solution directly to the lens. You can easily over apply lens-cleaning solution and it can become trapped around the outer diameter of the lens and lens retaining ring and possibly seep into the lens housing. If you apply it to the microfiber cloth, the possibility of this is virtually eliminated.

The one exception to this rule is for cleaning eyeglasses (including sunglasses and safety glasses), since there isn’t really any damage that excess lens cleaning solution can do (there is no place for it to seep into). Many lens-cleaning solutions come in a metered spray bottle. You can take advantage of the spray to help dislodge any remaining particles and float them off the lens surface. Give each lens surface a couple of squirts making sure that the entire lens surface is wetted. Then let the lens-cleaning solution work for several seconds. Allow the excess to drip off … taking most of the particles and grunge with it … before using the microfiber cloth. Allowing the excess to drip off also means less solution and dirt will be soaking into the microfiber cloth, so it will stay cleaner longer and dry faster to be ready for the next use.

This is often to most overlooked part of the lens cleaning procedure. I can’t tell you how many times I’ve watched photographers spend a lot of time to clean a lens, then waste all their effort by putting on a dirty lens cap. The lens cap must also be cleaned or it will transfer particles to the lens. Since the lens cap isn’t sensitive, you can resort to more extreme measures, including washing it under running water if needed. But the same basic cleaning tools and techniques described above can also be applied.

Step 6: Put All Your Lens Cleaning Tools Away!
Now that you are done cleaning the lens, place all lens cleaning tools and materials neatly away in your zipper-lock bag so they are ready for the next time. Don’t include any waste materials! Remember that this bag is only for clean materials or materials that can be used multiple times before discarding.

Keep an extra zipper-seal bag in your kit that can be used to hold trash.
When possible, let your microfiber cloth(s) dry. This may mean waiting until you get home and then taking them back out for a while. This is especially important on rainy days, as a soaking wet microfiber cloth will be of little help on the next day of your hunt or shooting match.

A paperclip kept in your bag of tricks can be used as a clothespin to hang up the microfiber cloth while it dries.

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