By
Tim Thumb on 04-12-2010
They say you should learn something new every day. And if you're a photographer, learning new things about the tools and techniques of picture taking ultimately manifests itself in the form of better pictures. That goes for pros and amateurs alike. A trick here, a bit of common sense there, and before long your pictures start taking on quality characteristics they might not have had earlier on. And that's what 'Rules of Thumb' is all about.
The thing about rules is that sometimes they're so basic, so obvious, just saying them can cock an eyebrow or two. An example? How about "Is your lens clean?'. Now before you raise your eyebrow and click to the next post on this site, go get your camera and look at your lens. I'm pretty fastidious about keeping my lenses dust and smudge-free even I'm surprised at how often I discover a smudge or fingerprint on my lens. And if you own a camera that tucks the lens safely away behind those thin, look-at-me-too-hard-and-I'll-break 'protection' blades, I'll bet there's a smudge or hunk of lint lurking there as we speak.
And how would you know? The lens is always facing away from you. You turn the camera on, fuss with the menus, and compose and edit your pictures while staring at the back of the camera. Chances are the only times you look at the front of your camera is when you take it in and out of its pouch. And unless you take the time to actually look at the front lens element, you're clueless as to how spotless your lens may or may not be.
As for the ramifications of smudges and rogue lint, they vary. Dust, while far from catastrophic, is the tamer of the two, and in the real world a few specs of dust won't affect the quality of your imagery much at all. Unlike dust that settles on your imaging sensor and manifests itself in the form of shadowy, fuzzy-edged blobs on each and every picture you take, the visual effects of random dust particles on the front of your lens are all but nullified in the final image. If you have enough of it, you might lose sharpness, but a few specs won't cost you a Pulitzer Prize.
Smudges are another story. Smudges affect the sharpness of your imagery, and the larger smudge, the greater the damage. Depending on the viscosity of the smudge, e.g. , standard finger smudges versus cheese-fry smudges, smudges degrade the color saturation levels of your images too. If you've ever cleaned a dirty window you know how much more vibrant the outside landscape suddenly appears after a round or two of Windex and a soft, clean cloth.
If your camera has interchangeable lenses, always make sure you examine the rear element of your lens each time you put it on; and examine it again before recapping it and putting it away. Smudges on the rear element are worse than smudges on the front element because the rear element is the one that projects the image onto the camera's sensor (or film). Unlike the front lens element, the rear element is only visible when mounting or removing the lens from the camera body. And when you're juggling a body and 1 or 2 lenses simultaneously you're more likely to leave a smudge on the rear element and never even know.
You have several options for keeping your lens surfaces clean starting with lens tissue, which depending on the brand come in packs of 25, 50, or 100. Lens tissue should be used 1 at a time, and folded over several times to create a cushy, pad-like surface. Unlike facial tissue (which should never, ever be used on a lens surface), lens tissue is lint and fiber-free and won't leave particles behind. Before cleaning a lens you should always breathe lightly onto the lens surface, which makes the tissue more effective at removing smudges. The tiny drops of moisture also serve to protect the lens coatings from scratches. To clean your lens simply breathe on it and polish it gently in short circular motions.
A second option (and one I personally prefer) are lens cleaning cloths, which are typically made of cotton micro-fiber or chamois material. Like lens tissue, lens cloths are lint-free and leave nothing behind when you use them. Unlike lens tissue, which you dispose of after using them, cloths can be folded away and used repeatedly. They should also be cleaned regularly otherwise you end up spreading whatever goop you cleaned off your last lens onto the new one. Cleaning is easy, and consists of thoroughly rinsing the cloth under warm water and a bit of liquid dish detergent. Rinse the cloth until there's no trace of soap bubbles, hang it up to air-dry, and you're good to go.
Lens cloths are available in a variety of easily-pocketable sizes including a few that fold away into tiny stuff-bags that can be attached to your camera or bag strap, or simply tucked away in your pocket. Lens cloths and lens tissue are equally useful for cleaning eyeglass and sunglasses, which like your favorite lenses, should never ever be cleaned with facial tissue, regardless of what Uncle Ted says.
For those of you who were raised in households that discouraged breathing directly onto polished glass surfaces, there are a variety of spray solutions available that accomplish the same goal. These sprays should not be sprayed directly onto the lens surface, but rather onto to your cloth or folded lens tissue. We (B&H) also offer lens cleaning kits containing everything you need to keep your lenses - for lack of better words - picture perfect.
One rule about lens cleaning you should never break concerns canned, compressed air, which along with removing dust particles can also severely - and irreparably - damage lens coatings.
