A Little Housekeeping Never Hurts...

I've just been working on a set of pictures I took in the snow of Scotland at about this time last year. The weather was pretty extreme for then - but would probably be considered fairly mild by Decembers standards, with about a metre of snow, temperatures of about -15 and a beautifully crisp light that just lit up the snow, the trees and the hills with a wonderfully warm glow. However, across all the pictures are a series of dark unhealthy looking blobs that can only mean one thing - theres Grot on the sensor.
Now I clean the sensor on the camera on a regular basis - there really is no other way to keep it squeaky clean. Some cameras have vibration systems that remove most of the unstuck Grot from the sensors when you switch them on - but I've always been a little concerned about where that shaken-off stuff goes to as the inner workings of DSLR cameras are fine pieces of engineering. Others offer weather proofed lenses and camera bodies that make it impossible for Grot to get it in the first place - right up to the point that the User changes lenses of course. As the average photographic enthusiast doesn't have dust-free clean rooms available there is always the chance for foreign bodies to turn up in the camera cavity whenever a lens is changed, and then it will adhere to the sensor as soon as you switch on and a charge goes across it. Worse yet is the situation where the camera is accidentally left switched on while the lens is actually being changed - and thats when everything within a radius of 20m is sucked straight past you, into the front of the camera and straight onto the sensor. I guess thats what I had done before taking the Scotland pictures... Doh!
Thankfully, Grot isn't the end of the world even if you have found a really bad dose of it. First priority is to clean the sensor - but this needs a steady hand and a great deal of care - its not a job to tackle without reading the specific instructions for your camera, probably buying some extra kit or even having it done for you by a specialist as getting it wrong can range from simply a muckier result next time you shoot to permanent damage to the camera shutter and other moving parts. You Have Been Warned...! Second job is to clean up the images you've already taken - and thats where my allergy really kicked in.
There were 320 pictures in the Scottish set - and they all needed to have about 120 Grot Blobs delicately, carefully but COMPLETELY removed from each of the them. ARRRGGGGHHHHH!!! I can normally expect to process a single image in a few moments - depending on what needs to be done. A quick tweak of levels and saturation to compensate for the way the camera records the file is a matter of a minute or two. More complex photo joins to merge two or more exposures to avoid horrible blown out highlights or impenetrable shadows can take fifteen minutes per completed image - but these Scottish horrors are taking about twenty minutes FOR EACH SHOT, testing Photoshop's Healing tool and my left mouse button to the max. Even removing the failed shots from the collection, leaving the panoramic sets for another day (and some more software) and only picking the sharpest, most representative, of them will mean a total of about 20 HOURS of work. Its enough to try the patience of a saint - and is certainly the best reason I can think of to do the housekeeping regularly and early to keep the sensor clean BEFORE I shoot.
Happy New Year - and may your pictures in 2011 be Grot free...
Graham