primary method,

If it's poorly assembled now, it's not going to be better after a year of use.

filter 67mm
RM 4500

filter 77mm
RM 8400
announced: 1/5/2010
1.5kg

Here's where an extra couple of steps will further aid in keeping the sensor clean. I've just removed a lens but before I put the cap on it I'm going to give the back element of the lens AND the protective lens cap a quick cleaning with my rocket blower. These extra steps help keep me from transferring dust from a dirty lens to the sensor in future lens changes!

RM5600 filter 82mm

google keywords : autofocus micro-adjustment

And stop looking at 100% images on your monitor: not only will it make you go blind, 50% screen resolution is more resolution than your printer can reproduce anyway.

77mm filter

EF lenses can be mounted on EF-S bodies, albeit with cropped image,

RM 6500
filter size 77mm

RM 2800
filter size 77mm

RM 3300
filter size 72mm

RM 8500
filter size 72mm

77mm filters
USD 2200

77mm filters
USD 1700
announced: 8/19/2010
600g

Here's a cleaning tip I learned years ago and assumed everybody else already knew, but apparently it's no longer a matter of common knowledge: before you use the brush, blow air through it a few times, using the blower (in the direction of the bristles, so as not to fray them). This puts a small static charge on the bristles themselves, and after doing this they will lift dust off the lens very easily, without any real effort and without just moving them around on its surface.

Only after dust is blown and then brushed off the lens, and only if necessary, should you use a wet cleaner and cleaning tissue on the lens: cleaning is the single most common cause of lens damage. Even then, most people recommend that a microfiber cloth should NOT be used to clean the glass area of a lens. The cloth is nice for cleaning the lens body and other camera gear, but because it traps dust each time it's used, it shouldn't be rubbed on the lens surface itself. The only thing most experts recommend for safe cleaning of the lens itself is lens tissue designed for the task: a fresh piece every time guarantees that you will not be grinding your cloth's supply of old dust back into the lens' coating when you clean it. The lens tissue itself will leave a little residue, but that's not a problem: just blow it away with the blower, and you're done.

In fact, it's better to leave something dirty than to try to clean it badly.

Moisture is the key to growth, and it can come from humid air, especially with low circulation.

hair dryer example

it will affect your other gear, take necessary precaution to separate them

take off the UV filter before leaving it to dry under the sun

As a chemist, I have also thought of poisonous gases, but (1) they may kill you before they kill the the fungus, and (2) they may corrode the mechanics of the lens, so better do not try this.

is widely considered the reference ultra wide lens

certainly slower than high end f/2.8 professional zooms,

advocate of 50mm lenses