Wednesday 22nd February 2012 – Clubnight

One of my objectives tonight was to show Angus and others how to clean the camera sensor.   Some of Angus’ photos displayed a large dust bunny in the frame.

Whilst doing the cleaning I explained the process with those present.

The extent of dust spotting can be determined by setting the camera to F16 or above and focus to manual.  Now take a photo of clear blue sky or a plain white surface.   Zooming in all the way on the finished image on the LCD screen and methodically inspecting the whole surface will reveal the extent of spotting.   Remember that dust spots at the top of the frame are actually at the bottom of the sensor.

Firstly, I explained that whilst most modern DSLRs have a special sensor vibration system built in which operates at either startup and/or shutdown, this doesn’t always remove persistent dust.

If you don’t change lenses then it’s unlikely that dust will be attracted to the sensor.  The sensor is electrically charged during its operation and this is what attracts dust when you change lenses, particularly in dusty environments.

The process involves switching off the camera before removing the lens.  By the way, please don’t attempt sensor cleaning unless your batteries are well charges.  Indeed some cameras will not permit you to expose the sensor if there is not enough charge left in the battery.

On the camera menu system there is an option to clean the sensor manually (Canon) or lock up the mirror (on Nikon).

I see sensor cleaning having a number of options depending on the stubbornness of the dust spots.

1. With the lens off and the camera facing the ground, use a Rocket Airblast puffer to blow surface dust away, letting it fall out vertically.

2. If this fails, I then use a Visible Dust brush which is a little battery powered rotating brush which statically charges by rotation.  With the brush stopped a gentle brush across the sensor surface should attract the dist to the charged brush.

3.  If stubborn spots remain, then I resort to using a Pec-Pad on a spatula dampened slightly with a drop of Eclipse Optical Fluid and carefully wipe across the surface.  The fluid will evaporate quickly.

4. Switch off the camera to drop the mirror into place.

Angus’ sensor was checked using an illuminated sensor magnifier.   Alli also got her camera sensor cleaned this way.

I had spent a while during the week creating a Pictures to Exe AV of the Panama Canal Transit in HD and displayed it during the evening.

Real thanks must go to Mike who supplied a large platter aof cake and goodies for tea-break.

After this, we ran our usual photo critique and saw Angus’, William, Edward photos.   William’s photos showed some unusual exposure issues which we discussed and played with using FastStone Image Viewer.  Some of them worked well in mono.

Edward has been experimenting with square cropped format and Angus, with mono.

Again time beat us and it was well after 10pm when we finished.   Congratulations to Jack Thompson for obtaining a Commendation at the recent AV Festival.


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