Keeping Your Sensor Clean

While the advent of digital sensors, in many ways,  is the rebirth of photography it also brings some new challenges that film shooters didn't have to worry about as much.  The biggest one is photo sensor cleanliness on Digital SLRs.  With film, if there was a small spec, it usually got carried off when the film advanced.  Occasionally there was a big enough chunk of foreign mater that would scratch an entire roll of film but this was rare.  In today's digital world, when a small speck of dust gets on the sensor, it can stay in that spot indefinitely resulting in a spot on each and every photograph.  While this is typically easy to get rid of on every photo, it is tedious and lengthens an already complex workflow.

Prevention of sensor contamination becomes important.  Here are some tips for keeping your sensors as clean as possible:

1.  Try to change lenses in a clean environment

2.  Change lenses only when necessary

3.  When changing lenses, make sure the camera mount is pointing downward

4.  Minimize the time that the body spends without a lens attached

5.  Make sure that rear lens caps and body caps are clean.  I recommend washing them once a month.  I just throw them in the dishwasher.

6.  Make sure rear lens elements and mounts on the rear of the lens are clean

7.  Do not put rear lens and body caps in your pockets - this is a haven for lint that gets on the caps and in turn are transferred to your sensor

8.  Do not trip the shutter with a body cap on - even after cleaning, these are dirty and shed particles

If your sensor does get dirty, you will need to clean it or have it cleaned.  Before using any commercial or homemade product that physically cleans the sensor, put your camera in sensor cleaning mode.  This locks up the mirror and opens the shutter.  Take a blower bulb that is clean and has had a few shots of air blown through it to clear out any accumulated dust and put the tip of the blower to the edge of the lens mount and blow all around the sensor.  Then turn off sensor cleaning mode to close the shutter curtain and drop the mirror.  Make sure you do this before you put a body cap or lens on to prevent from stirring up any dust on them and redepositing them on the sensor.  At this point you should test your sensor cleanliness by mounting a wide angle lens, setting it to a small aperture such as f/16 or f/22 and taking a photo of the sky or some other solid and bright area.  Analyze this photo on your computer screen to look for sensor dirt.  If dirt is still present, you may need to go to a physical contact  cleaning procedure.  There are several available.  I use Sensor Swabs with Eclipse Fluid from Photographic Solutions (www.photosol.com).  A new product called the Sensor Brush (www.visibledust.com) is gaining popularity.  I have some personal reservations about this product but those that use it swear by it.  Others make their own out of spatulas and pec pads coupled with Eclipse.  Whichever method you use, the procedure for cleaning is to again put the camera in sensor cleaning mode and then use a smooth single stroke from left to right.  If using one of the Eclipse Fluid techniques, this should be followed followed by a counter stroke from right to left.

An ounce of prevention goes a long way in keeping your sensor clean.  By following the steps above, you can minimize the need to clean sensors but when you do need to clean them, proper cleaning is important.  The camera manufacturers will be happy to clean your sensor for you for a small fee but this means not having your camera for two to four weeks and they use techniques very similar to those described above.  Any time that you send your camera in for service, request a sensor clean as part of the service.  Canon does this as a matter of routine but not all manufacturers do.

Wildflowers Running Rampant

December through February was the rainiest period in southern Arizona in over 30 years.  January and February produced more rain than the entire 2002 and 2003 years combined.  Southern California received even more rain.  When this happens, southwestern photographers start thinking about wildflowers and there certainly have been areas of dramatic color this late winter and heading into spring.  Much of Arizona and the southernmost parts of California are already past their peak but there will still be many areas with great blooms.  If you are in these areas or are visiting the area, don't let this opportunity pass you by.

Tilt and Shift Lenses

While browsing the classifieds this winter on www.NatureScapes.net, I ran across an advertisement for a use Canon 90mm Tilt/Shift lens.  After contacting the seller, I decided to try the lens, especially since he was willing to give me a full refund if I didn't like it.  I got the lens just in time for the initial wildflower bloom in the Sonoran desert and it has opened up a whole new world of photography for me - one that large format photographers have experienced since the dawn of photography.  By being able to tilt the front element downward, you can "lay-down" the plane of focus through some physics called the Scheimpflug effect.  So instead of the plane of focus being parallel to the film/sensor plane, it can now diverge from that.  The boon to photographers is depth of field.  Since I can make the critical focus plane to be the flowers in a field of flowers, I now do not need to shoot at f/16 or f/22 to get adequate depth of field and am not susceptible to the resulting slow shutter speeds that can cause motion blur due to wind.  Aperture still works the same way - stopping down the lens makes more of the area in front of and behind the critical plane of focus sharp but if the plane of focus is the flower field, now I only need to stop down enough to gain a few inches of focus depth to get the stems beneath the flower pods sharp instead of having to stop down so much to get everything from inches in front of the lens to infinity sharp.  A photo that might be impossible with a regular 90mm lens even at f/32 is now possible at f/5.6 - see the photo immediately above.  Similarly if you have two objects that are a different distance from the camera and offset from each other, you can tilt the lens left or right to move the focus plane at a vertical angle resulting in both objects being sharp.   For example, if you have two people standing next to each other, one slightly behind the other, you can get them both sharp without having to use such a small aperture that the background comes into focus.  These lenses also can shift their front element left to right or up and down.  This is useful in two ways to the outdoor photographer.  By moving the front element up or down, you can keep the camera's sensor/film plane parallel to the subject you are photographing resulting in no perspective distortion.  As an example of this, when shooting a tree (or any vertical object such as a building) with a wide angle lens, since you have to point the lens up, it looks as if the tree is falling away from you.  By shifting the lens, you can keep the back of the camera parallel to the object and shift the front element up and can correct this phenomenon.  Another use is for perfectly stitched panoramas.  By shifting from side to side, you can create panoramas where you never have to swivel the camera making stitching a breeze.  This also negates the need to have the tripod head, and camera perfectly level for easy stitching.  Needless to say, I kept the TS-E 90mm lens.  I liked it so much that I bought the TS-E 45mm lens as well.  Canon also makes a 24mm lens that I am starting to think about!  A warning to those that do not want to manually focus - these lenses are not for you.  Due to the nature of tilt/shift lenses and the fact that focus occurs in 3 dimensions relative to the film/sensor plane, autofocus is not possible with these lenses.

DuckShop 2005 Another Success

Spring has arrived and our feathered quacking friends have once again left the warm southwestern climate for points north.  Between the beginning of December and the end of February, Southern Arizona has only had 4 weekends without rain as record rainfalls have swept through California and Arizona.  DuckShop participants were extremely lucky this year because the 4 weekends that the DuckShops were held, were the same four weekends that did not have rain.  The abundance of rain this year filled many areas with water that have been drought ridden over the last several years which spread out the waterfowl significantly.  This year's DuckShops had a lower density of ducks but in some ways that made photography easier as isolating individuals was easier this year than in previous years.  All of the groups were still treated with at least 9 species of ducks to photograph in each workshop.  A heartfelt thank you to all of those that participated.  We had some great times this year and everyone went away with some stunning photographs.  Stay tuned for DuckShop 2006 dates - those on this newsletters distribution list will be the first to know.

Waterfowl Essay Series

For those that are www.NatureScapes.net members (those that aren't, what are you waiting for?), I have started a weekly Waterfowl Species Essay in the Photo Essays Forum.  Each week I will profile a waterfowl species along with several photographs.  The series promises to be very informative with information about the various species and tips on how to best photograph them.