Is this dust or sensor corrosion?

[willie_901]

As others said, these do not appear to be deamination defects due to corrosion.

I think they are a combination of dust and oil/grease debris. In any case this is a very mild case of contamination. The sensor corners can be the most difficult to clean. I think the larger areas may be traces of oil or grease from lenses or the shutter mechanism.

There are two kinds of sensor debris:

- Solid objects (dust, hair, etc) that are not bound to the cover glass. These usually blow off with little effort. Before cleaning be sure to cycle your blower a few times to make sure it does not spit out debris.

- Solid objects that are bound to the sensor glass. These may be inherently sticky or they may be attached by evaporation after incomplete cleaning. Some are easily removed by hydrophylic-based cleaning methods. Some are small amounts of residue from oil or grease. These are removed by hydrophylic-based cleaning methods. Sometimes oil based residue just smears if the cleaning solution can not completely dissolve the reside. You will never clean the sensor if the cleaing fluid does not completely dissolve bound debris and residue.


I try hydrophilic cleaning solvent first. When needed I finish with a hydrophobic solvent.

Of course the solvents have to be designed for sensor cleaning. For instance, many common, off the shelf isopropyl alcohol solvents have a small amount of lotion to minimize skin drying. Other general solvents can damage sensor assembly surfaces other internal components.

My cameras have vibration based sensor cleaning. I have not had to manually clean them for some time.

 

[raid]

Thanks for the feedback Willie. I hope that my camera sensor has no oil/grease debris.

 

[Darthfeeble]

I've had good luck with Eclipse solution and Sensor Swabs. The handle of the swab makes it difficult to put too much pressure on the sensor yet is able to put enough to get the job done. A few drops of the Eclipse on the swab and swab one way, turn it over and swab the other. Toss after that, don't try to reuse.

 

[raid]

I've had good luck with Eclipse solution and Sensor Swabs. The handle of the swab makes it difficult to put too much pressure on the sensor yet is able to put enough to get the job done. A few drops of the Eclipse on the swab and swab one way, turn it over and swab the other. Toss after that, don't try to reuse.

I have the same set. Thanks!

 

[Darthfeeble]

Do you put a little flex in the handle when you swab? I make it bend about ⅜ to ½ inch. Usually just one swab gets it done.

 

[raid]

Yes, I also push gently and swipe across.

 

[571514m3]

Yes, I also push gently and swipe across.

I seem to be lucky as I have always got away with just the arctic butterfly brush and using the loupe. And with the M-P 240 now e years old it seems to have settled and dust is rarely a problem. The M-D has had almost no problems.

BUT.....and I think I am highjacking this post a little 🙂

Whenever I read about 'dust removal' I am reminded of optical resolution when recommendations are about f8....+

This is what I refer to, and to be honest since reading it first I have checked myself and rarely go over f5.6, with better results.

Quote: "The lens opening or aperture is the deciding factor for the resolution capabilities of any optical system. The larger the diameter in relation to the focal length, the larger is the theoretical resolution. Each subsequent smaller aperture will half the visible resolution.

Unfortunately, the performance of most lenses is usually less wide open than when moderately stopped down. The theoretical values at f/1.4 can hardly be reached in the real world. Optimum performance usually is not reached until stopping down to a range of f/2.8 (at best) to f/5.6 or f/8. Please note that due to diffusion within the emulsion these figures extend to f/11 with most color and black and white films.

This is especially important with smaller sensor sizes. While a 35mm full frame sensor is capable of a theoretical resolution of 60 megapixels at f/5.6, a 2/3 sensor is reduced to just 4.4 megapixels at the same aperture."

From this:
https://gmpphoto.blogspot.com/2014/11/the-pixel-race-does-it-really-make-sense.html

What do you think, is it right to dumb down the resolution in exchange for not having evidence of dust?

 

[raid]

Leica optical designers always recommend using lenses wide open.

 

[Bill Blackwell]

... And what's that vertical line down the entire middle of the sensor, causing the left and right sides to have different shades? ... Edit: just realized that line may not be on the sensor but on the subject -- a corner or wall?

Leica sensors are stitched, so over processing can reveal the "seam" separating the two sides. Normal processing of files in PS is rarely, if ever, an issue.