Wednesday, August 23, 2006

Sensor Cleaning - No Guts No Glory

The technology of digital photography is advancing and manufacturers are developing systems to fight dust build-up in your camera's imaging sensor. Olympus introduced it first and now Sony's Alpha DSLR has one. But these two are still exceptions and until anti-dust feature becomes standard in the majority of DSLR's here's a small guide to cleaning your DSLR's imaging sensor.

Since the camera I have is a Canon EOS 20D, most of the descriptions I made here are based on that. But I suppose the principle of executing the job is universal.

1. Check for dust in your sensor. This is fairly easy to do. Switch your lens to manual focus and then focus to infinity. Set your aperture to f/22 (or f/32 if your lens has it) and shoot a light colored plain surface (or a perfectly clear blue sky). Now check the resulting image in your computer monitor (Never trust your camera's LCD screen.) and see how much dust you have.

2. Decide whether the dust problem is minimal or otherwise. If it's something that can be easily blurred out at wider apertures or something that can be easily cloned out in post processing then you're fine. Don't sweat on it. To clean or not to clean depends on your judgment, of course. If you decide to clean it . . .

3. Have your cleaning kit ready. There are sensor cleaning kits available in photographic supplies shops and each kit should include a cleaning solution and some swabs. Other inclusions will vary. Some may include a dust blower, some lint-free paper, brush, etc.

4. Clean the whole camera first. This will minimize the dust you have to clean out of your sensor. A dirty camera body increases the risk of more dust falling or flying into your sensor when you open the lens mount, the pelical mirror and the shutter. The sensor is the last one you should clean.

5. This is important. HAVE PLENTY OF POWER SUPPLY FOR YOUR CAMERA. You should do your cleaning with the camera plugged in to an A/C adaptor or, at least, have your battery fully charged. That's the manufacturer's recommendation. I'm not sure how much power the camera consumes to hold that shutter up and open but you wouldn't want that shutter to suddenly close down when the power runs out and while your cleaning swab is inserted in there. That would simply cause a major, major damage to your shutter.

6. Don't worry about scratching the sensor. They're tougher than you think. I myself use a DIY swab - a couple of dental sticks (toothpick) taped together with a folded lint-free paper at both ends. But I'd rather recommend the commercially available ones. They're just not available here in Doha that is why I'm using DIY versions.

7. Now, put a couple of drops of the cleaning solution on the cleaning swab.

8. Sweep, don't wipe. Next, put the tip of the cleaning swab at the upper left side (we'll call this the starting side) of the sensor and gently sweep to the other side (this will be our ending side). Lift the swab and go back to the next line on the starting side and repeat the action. Do this until you've swept the sensor’s entire surface. Don't sweep back and forth. You're just sliding dust all over your sensors. THAT may cause some scratches. Then, sweep once from the top of the ending side to the bottom and you're almost done.

9. Remove excess solution. Using the dry tip/end of the swab repeat the actions described previously to clean the sensor dry.

10. Close the shutter. Just make sure that there are no obstructions there.

And you're done! Start from no. 1 again to see if there are any dusts left. You may need to repeat the entire process once or twice more. Yeah, I know, it's a tedious and repetitive process.

Time was when I would clean my camera's sensor on a weekly basis - regularly and without fail. Until I found it too troublesome so I learned to live with a few speckles on the image that can be easily cloned or blurred out.

I remember writing about the same topic in litratista.org ('Can't find the link now. It must be buried down to the bottom of its long list of articles now.) And I remember receiving some objections to it. The system works for me. If you're dubious about it or just simply not up to it, then don't do it. It's your sensor not mine.

But if you feel that cleaning the sensor is something that you can do on your own, I hope you find this article helpful.

Cheers,
alexdpx

3 comments:

Andrew Villasis said...

Thanks Alex

Hocchuan said...

No Guts No Glory talaga alex hehe.. hmmm.. I'll think about this when I need to clean my sensor. :p Thanks Alex.

alexdpx said...

No problem Andrew and no rush Pat :) Clean only when necessary but when you have to - don't be scared.