CCD/CMOS Cleaning Tutorial
#2 - A Close Look
There are several types of tools you can choose from to clean your sensor. Here's a close look at a couple of the time-proven ones and a few that should be avoided at all costs.
#1 - SensorSwabs are pre-assembled swabs that come in a sealed plastic wrapper. They are designed to have one or two drops of methanol placed on the tip, and then wipe the sensor. A SensorSwipe (opposite sidebar) is a highly pliable swab which is wrapped with a PecPad and then the same fluid is applied to the tip. SensorSwabs must be discarded after one swabbing whereas just the individual PecPad must be discarded. Both of these swabs have been stalwarts in the sensor cleaning business for many years and when used according to the precise instructions, are capable of giving you a 100% dust-bunny free sensor.
#2 - Static-charged Sensor Brush
A sensor brush has a static charge placed on the tips of its bristles and then picks up dust particles as it sweeps across the sensor. The most common way to charge a brush is to rustle the filaments with a blower for about 5 to 10 seconds. Are all sensor brushes on the market the same? The brush pictured above uses filaments imported from India and assembled in the United States. Almost every other sensor brush comes straight from China or Germany, pre-assembled with white nylon bristles. These cheaper brushes will not hold their shape very long and will start to splay outwards after a little use.
The beauty of sensor brushes is that they can be used over and over again as long as the filaments are kept clean. Most of our customers use a brush once a day and then wet-clean every week or two, depending on various factors. Sensor brushes help keep loose dust from taking up residence on your sensor and turning into super-glued specks, which will keep your wet-cleaning to a minimum. They're a one-time purchase and will last for years.
GOOD BLOWERS & BAD BLOWERS
Blowers alone cannot clean sensors by themselves, but they do have a prominent part to play by blowing off loose dust particles.
OK, so when is the right time to use a blower and which ones should be used? You need to have a good look at the sensor before you clean it with any wet or dry tool. If you see any particles with the naked eye, then get a bulb blower like the Giottos Rocket and carefully blow off the sensor. You'll hear this mantra repeated throughout this tutorial that the biggest risk in cleaning a sensor is if there are big chunks of debris sitting on the sensor and the Rocket cannot dislodge and remove them. At this point, it is advisable to try canned-air. If canned-air doesn't budge the speck, then your next step would be to try a sensor brush or a rolled-up micro-fibre cloth with tweeers to dislodge the speck.
WHEN AND HOW TO USE CANNED-AIR
There is a bit of hysteria about how dangerous canned air is but it has recently been disclosed that many Canon technicians depend greatly on it. If you follow these guidelines it is actually very safe:
• The preferred time to use canned air is when a bulb blower cannot dislodge a big, solid particle which can be clearly seen with the naked eye.
• Don't shake the can beforehand; there's nothing to mix.
• When spraying with it, keep it perfectly upright at 90 degrees and move the object you're blowing NOT the can.
• Always let a little air out before spraying an optic. Propellant has a tendency to build up towards the valve and will come right out if the can has been sitting for a while
• Don't let the jet-straw get any closer to the sensor than 1" or 1½" or just inside the lens mount.
• Use very short "staccato" bursts, no more than a one second shot; "freezing" will only occur when you use a prolonged stream of air.
* You will notice with canned-air that the jet-straw moves around as you pull the trigger, that's why it is strongly recommended to have the camera body on a tripod and use both hands to operate the air. IOW, hold the can in one hand and control the direction of the straw with the other; so instead of the air going helter-skelter (great song), you can pinpoint it on the sensor. This is extremely appropo for full-frame sensors where you may need to shoot a jet of air on each of the four quadrants.
Using these guidelines, we have never had any problems with canned air. If by some chance the canned air cannot remove the dastardly stuck-on specks, try ignoring them for a day or two, in many cases, they will pop off on their own. If you can determine that the speck is a dust mote and NOT a big particle of debris or grit which canned air should be able to remove, then it should be safe to proceed with a wet cleaning. If it definitely is an unmovable piece of grit that canned-air, a sensor brush or cloth cannot budge or you're not sure what to do, then, by all means, send it to the manufacturer for cleaning.
What's brown and sounds like a bell? Dung.
Foot-pump. How dirt, silt and contaminant-free is the air at floor-level? This device was used to blow off slides way back in the emulsion days, but there is absolutely NO use for it with today's digital cameras. There was an incident where a guy was using one to blow off his sensor when the tip flew off right into the sensor making a nifty scratch. Avoid at all costs.
On the next page, we will complete our list of dangerous sensor cleaning tools.
NOTE: From the customer feedback we have received, including up to the present, we can tell you that ALL major camera companies are hit-or-miss with sensor cleaning. We'll take it one step further and estimate that for every person whose sensor is cleaned "pretty well", there are at least 2, 3 or 4 others whose send-in was a total waste of time. EXAMPLE Some cameras come back even worse. Also, most camera manufacturers will clean your D-SLR for free one time within the first 12 months. After that 1st cleaning, Canon USA, for example, now charges $60.00 for every succeeding sensor cleaning. Just think of the sensor cleaning kit you can buy for $60.00 if you could do it yourself, and that kit will probably last you 3 or 4 years.
What all of this tells us is that using the proper tools, even the ones that seem so easy to use, is no guarantee of obtaining an immaculate sensor. So while one Canon, Nikon or Fuji technician really knows what he's doing, the techie sitting next to him doesn't have a clue. When you send your camera in for cleaning, you're playing "sensor roulette". That's why the veterans choose to do it themselves and have total control over the process.
A guy is playing golf and duck-hooks a ball out of bounds and into the woods. He looks for it and finds that it has hit a little Leprechaun on the forehead, making a good-sized knot. "Little man, are you OK?" "A little sore, sir, but you are so kind for caring about me, I am going to give you 3 gifts. One - you will always have as much money as you need. Two - you will always be in the best of health. And three - you will have the most fulfilling sex-life of any man." The guy finds all of that hard to believe, but he thanks the little man and leaves.
A couple of months later, he hits another ball into the woods and finds it has hit the same Leprechaun in the forehead. "Little man, are you OK?" "Yes, fine sir, I'll be OK, but how have you been doing since we last met?" The man replies: "Well, I always have money in my pocket, no matter how much I spend, there's always money in my pocket. And I have been feeling great, running 20 miles a day, the doctor says I have the body of an 18-year old. And I have been having incredible sex with 25 gorgeous women a week, but that isn't so good." "But why not, sir?" says the little man. The guy replies "Because I'm a priest!".
You are here >#2 - A Close Look
#3 - Preparing a Copperhill Swab
#4 - Swabbing Illustration
#5 - Important Points
#6 - Tips & Links
A SensorSwipe is wrapped with a QuikStrip as shown in this photo. You should be able to see the tapered head of the 'Swipe and how the QuikStrip takes the exact same shape when applied properly. Most sensors have sidewalls and a tapered head allows you to get right up against those walls and even into the four corners. We will show you how to prepare a swab like this on the next page.
Pictured - a PecPad wrapped SensorSwipe (left), a bare SensorSwipe (right)
This is a shot of a battery-operated blower charging a sensor brush.
Must-read review of the CopperHill SensorSweep - HERE
Another use of canned-air is charging a sensor brush. We also use it on bodies and lenses and it is invaluable when it's time to clean our computers' internal components. Every digital photographer should have a can in his studio or office and know how to use it properly.
Good blowers as discussed on this page are your first line of defense against dust. What is left on the sensor is then approached by other dry tools like a sensor brush and a sensor pen.
But even after all of this, your sensor WILL eventually get the dreaded stuck-on dust-bunnies. That's when a wet cleaning is demanded. Sensor swabbing uses what the CCD and CMOS do BEST:
ATTRACTING AND HOLDING DUST PARTICLES IN ONE FLAT PLANE - THE SURFACE OF THE AA FILTER!
Swabbing takes a moistened swab and with a double-swipe cuts through chamber lube, dislodges stuck-on dust, collects all of the debris into the cloth-covered tip and REMOVES it all.
IMPORTANT: As you compare the wet tools discussed in this tutorial with other methods, keep in mind that each side of the swab's tip touches the sensor surface only once and then the pad is discarded. Some of the tools on the market have you dabbing the sensor several times with the same tip, and, generally these should be avoided.
Comprehensive sensor cleaning involves blowers, brushes, swabs and, nowadays, a sensor magnifier. When used with all of the guidelines presented in this tutorial, you will most certainly be able to get your sensor 100% dust-free. Some people will have a comfort zone using the wet tools, but others may not for various reasons. This is quite understandable. Only YOU can determine which way to go, so we urge you to read as much of this tutorial as you can before making up your mind.
"The world we've made, as a result of the level of thinking we have done thus far, creates problems we cannot solve at the same level of thinking."
"This brings us to the definition of insanity: doing the same thing over and over and expecting a different result."
....................Rita Mae Brown