Cleaning my camera sensor!
The one major, major flaw in older digital SLR cameras like my Canon Rebel XT (that's a 350D for those outside the US) is that they are dust magnets. Changing lenses or even using the zoom on a telephoto lens seems to positively suck dust and dirt inside the camera, where it sticks to the mirror, the focusing screen, and – worst of all – the sensor array itself.
Newer DLSRs have fancy vibrating ultra-sonic cleaning mechanisms that can shake dust loose from the inner workings of the camera, mine does not. As a result, my nearly 3-and-a-half year old camera was becoming something of an embarrassment... clear blue skies were covered in dust spots that had to be cloned out in Lightroom or Photoshop, and any shot stopped down below ƒ/16 was absolutely covered in horrid little black dots as the dust was brought more into focus. I'm using a tripod, stopping down and doing a lot more long exposure photography these days, all of which are guaranteed to show off those spots in all their unsightly glory. After our trip to Central Oregon last month, these spots crossed the line from "slightly annoying" to "I can't stand these damn dust bunnies!"
So what to do? I could just take my camera into a pro photo store and have them clean the sensor, but there were many reports on the web of cameras returning from service either exactly the same or worse than when they went in. That sounds like $60 poorly spent to me. So I decided to look into self-cleaning solutions, as scary as that sounds! Again and again, the same name kept coming up: Copper Hill Images. Their website posts the most detailed instructions on cleaning the interior of a digital camera I have ever seen, and they sell the kits that give you the tools to do it as well. So, after reading and rereading the site and other people's opinions of the method, I went ahead and ordered a kit. It arrived yesterday, and I have spent the morning giving my camera a thorough, well-overdue cleaning. How did it go? I think pictures tell the story. These are shots of my computer monitor with a sky-blue image filling the whole screen (the dust is always more visible against the sky in real-life, so that's what I set out to simulate on another grey Portland day!). The aperture was set to ƒ/22 for all these shots to bring the dust into focus as much as possible.
First up, a shot taken before any cleaning:
Disgusting, eh? There must be over 100 individual spots here, including some really big ones. This is what comes from changing lenses out in the open and rarely cleaning your camera!
After taking each shot, I brought them into Photoshop and ran Auto Levels (Command-Shift-L) on a duplicate layer of the image. This allowed me to really see each and every dust bunny on the image, which I've circled in red.
My first step was to get the SensorSweep brush, give it a light static charge by blowing air on it from a blower and lightly – oh so lightly! – brush it over the sensor to remove any loose dust particles. This done, I took another test shot:
A huge improvement already! You can see that the large spot has moved because I used a different focal length to take this shot compared to the last shot - indicating that this one is on my lens or filter, not the sensor.
Next, I thoroughly cleaned all my lenses and filters with the brush followed by lens tissue moistened with optics cleaner. Getting there! Now for the final, most daunting step... wet cleaning the sensor itself. This uses lint-free photographic wipes moistened with a drop or two of Eclipse optic fluid, carefully wrapped around a little stylus to do the job. With a steady, light hand, you brush the wipe across the sensor one way and then back the other, using one side for the first stroke, then the other side for the second stroke. Whatever you do, don't go back in and do another wipe after this - you'll just end up depositing all the removed dirt back on the sensor array!
And the result:
Still not perfect, but what an improvement over the "Before" photo! The big spot still seems to be on my lens – I'll have to investigate its exact location further – but we're down to a handful of dust spots on the sensor. Hopefully, with regular cleaning sessions, I can continue to reduce this number even further!
I am already very impressed with this method of cleaning, but it's certainly not for everyone. If you have poor eyesight, unsteady hands or are terrified of damaging your camera, then I would recommend that you look into alternative methods instead!
Posted in: chaosboy, photography on June 6, 2009 at at 12:41:00 PM 1 comments