Tuesday, May 20, 2008

Sensor Cleaning

Here's a quick guide on how I clean my camera's digital sensor.

I use the SensorKlear pen by Lenspen. I turn on the camera, go to the menu and select Mirror Lockup, and then press the shutter. Then remove the lens and carefully wipe the SensorKlear pen across the sensor a few times. This is the way to remove dust spots that are stuck on the sensor which won't come off by just using an air puffer.

A Rocket Blaster is a good general way to remove dust from the inside of the camera. Simply turn off the camera, remove the lens, and hold the camera with the front facing down, and then puff the air in to the body. This will stir up the dust, and hopefully make it fall out of the camera. Never use CANNED AIR to blow out the camera, this can destroy your camera. There are chemicals in the air, and it comes out very cold.

The only word of caution I'd provide regarding using the sensor pen is that there is lubricant in the camera for some of the moving parts. If by chance you rub the wrong area of the inside of the camera this could wind up on the pen. Rubbing this on the sensor would then smear the lubricant all over the sensor and wreck your day big time. So be careful when your using the pen inside the camera. Don't get distracted, don't touch anything except for the sensor itself!

Other Cleaning Methods Include:

Sending your camera out to be professionally cleaned. This could take some time, and will cost more than a couple of the pens described above.

This method was discussed on the Tips From The Top Floor podcast, and involves covering the sensor with a load of goop! I'm not brave enough to even consider this method, but thought to mention it.

Dust / Dead Pixel Work-around
For spots that cannot be removed, or if you have a dead pixel on a point and shoot camera or a dSLR, this is one way to post-process it out of photos. If you have a pixel or two that always show up bright red or blue for example, it can be annoying, and tough to fix. If you have 10 of them, you'll be hating your camera. I read this tip a while back and thought to include it here. The method is to take a photo that is pure white, and save it as a reference image. With a dSLR set the exposure so that it is extremely over exposed and stop the lens down to f/22 or so. This might be a 2 second exposure at f/22 that you point to the sky at ISO 200 for example. Then save this image on your computer. Later, when are you processing an image that you want to remove the bad pixel(s) from do the following:

1) Open the image you took that needs fixing (bottom layer).
2) Open the reference over exposed image, and add it as a layer to the image from step 1 (top layer).
2) Then change the top layer's blending mode to SUBTRACT. This should remove the pad pixel(s).

Some newer cameras can record the bad pixels in a reference file on the camera, and this can be used automatically with the camera manufacturer's image processing software.




mon@rch said...

Sensors are a nightmare for me and I have a fused dustspot on my D70s that I need to send it in to be cleaned. I have been extra happy with my D300's shaking sensor!