Sensor Cleaning

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Cleaning the sensor of the M8 is a basic process and required of all owners.

There are a number of web resources which will be listed at the end of this article, however we will go over the basics here. Although there are a number of different techniques that many would recommend, this page is intended to describe a basic process which seems to work. Remember that there is no specific method recommended by Leica and they endorse no specific set of tools or materials. A note on nomenclature. We will be using the word "sensor" within this article to mean the cleanable surface of the thin transparent cover affixed over the active surface of the sensor itself.


How do I know that my sensor is dirty?

Dust leaves sharper shadows when imaged at small apertures, so add a lens to your camera and set it to its minimum aperture. Take a picture of the sky, a piece of paper held over the lens, an expodisc, or of a white lcd screen. Really, almost anything will do as long as it is reasonably bright, a uniform color and has little if any detail. The technique is to set the lens aperture at its minimum and the shutter for a "normal" exposure or perhaps one ev more. Set the focus so that there is no possibility that the article being shot might be in focus, lest one attempt to clean off distant fuzzy birds. If the shutter takes an appreciable length of time, move the camera around for good measure. Examine your test image at 1:1 and look for any hints of cast shadows. Since there is some distance between the surface of the sensor's cover glass where any dust that might be removed by the owner and the active sensor itself, small dust particles will leave a somewhat fuzzy cast shadow. The contrast can be boosted to emphasize the little devils.

If you are having trouble finding your sensor dust, try loading your test image into Photoshop and adjust with autolevels.

Dirtysensor.jpg

©2007 Marius A. Eriksen used with permission of the artist

Where on the sensor surface is the dust located?

If the camera is held with the sensor facing you and with its top up, then the dust particle you are chasing is located on the same side as it appears on your test shot but flipped vertically. This is not as weird as it sounds since a lens turns an image both upside down and left to right, but since you are facing the sensor you have flipped it left to right once more. This is as one might view the ground glass of a view camera from a point inside the bellows.

Level one - the huff and puff

Materials Recommended 
Rubber bulb blower such as Giotto's Rocket Blower

Point the tip of the blower close to but away from the sensor surface then squeeze sharply. Be careful not to touch the surface of the sensor with the tip of the blower as it may transfer contaminants onto the sensor surface. Although some owners have reported good results with "canned air", it is not recommended by this author since its contents are not necessarily clean or dry. If someone might be able to recommend a specific type that produces consistently good results, that might be appreciated. Meanwhile, I would not attempt such a stunt at home for fear of creating a worse mess than that which I started or worse.

Level two - dry cleaning

Materials Recommended 
Sensor brush


Level three - wet cleaning

Materials Recommended
Visible Dust Ultra MXD-100 (green) 1.3x sensor swabs
Eclipse E2

Links to other sources

Links to vendor web sites

The vendors below are referenced in this article but are not endorsed in any particular way.

--Rwfreund 02:22, 31 August 2007 (CEST)