I tried to destroy the sensor, I really did!

Discussion in 'Open Discussion' started by lenshoarder, Apr 24, 2012.

  1. lenshoarder

    lenshoarder Mu-43 All-Pro

    Nov 7, 2010
    I bought a display camera. It had been the display for about a year, out in the open, but without the lens mounted. I think people mistook it for a fingerprint scanner since the sensor was a full of fingerprints, dust and general gunk. It was cheap and the lens was worth more than the purchase price so why not?

    I cleaned the sensor last night. Yes, I could have gotten it professionally cleaned but at the price I paid for it, it just wasn't worth it. Yes, I could have gotten some of those clean room made sensor swabs but they cost almost $1 each. Once again, not worth it. The way I looked at it, nothing I do to it could be worse than a year of people putting their fingers all over it. I had q-tips (cotton swabs), 99% isopropyl alchohol and and baggy full of pec pads. What more do you need? I made a "sensor swab" by cutting up a credit card and affixing a pec pad to it. I then dipped it lightly in alcohol and swabbed away like you are supposed to with a sensor swab. This turned out to be a major mistake. It ended up pushing the grease from the fingerprints onto the edges of the sensor which ended up being a major hassle. Also, contrary to what some people say, 99% alcohol does leave streaks. I knew that before from prior experience. I then broke out the cotton swabs, dipped them in alcohol and started to scrub. This clean up a lot of the gunk on the sensor, but left a lot of streaky residue as well as the gunk that got left on the edges when I tried to swab. Thinking back, I should have started with the swabs and worked my way in from the edges. There was also this one speck that refused to move. I scrubbed and scrubbed to no avail. I was afraid it was permanent. So I did way I would do if I was out and about and had a stubborn speck on a lens. I got a plush microfiber cloth, like what I use to dry off my car. I then huffed on the sensor and polished it using the microfiber cloth. That got rid of the stubborn speck. It also got rid of a lot of the residue and gunk along the edges. It was looking pretty good. To finish it off I made a micro swab using a further cut up credit card and the pec pads. I use this to swab down the sensor with alcohol again. I then boiled a cup of water in the microwave and use the steam from that as a source of distilled water. I moisted up my micro swab with this steam to rinse off any of the alcohol residue. In the end, it turned out pretty good. I wish I had taken a before picture of the sensor.

    It's not my first time playing with sensors. Yes, I know it's not the sensor but the AA filter over the sensor. Contrary to popular wisdom that says that the "sensor" is so delicate that a flea fart will permanently damage it, I know that the glass covering a sensor is more or less the same as the material used to make a filter or a lens. It's a lot tougher than many people think. I ended up doing pretty much everything the "professionals" tell you not to do. I did forego the scotch tape though. That's just crazy.

    The proof is in the pudding. Here's the pudding. A couple of shots from the backyard.


    I don't know why I was surprised, but the camera had never taken a shot before. It started out at number 1. Considering that the camera was displayed without lens, no memory card and most importantly, no power, that should have been expected.

    As for how clean the sensor is, here are some dust maps.

    Here's one taken at F22. This shows the dust most clearly. There will be a original shot where it's hard to see the dust and then an enhanced shot which makes it easy to see the dust.



    Enhanced to show the dust.


    I know that it looks like a lot of dust, but I've seen worst even from clean cameras. You might not think your camera has dust, but I can guarantee you that your camera has dust.

    Here's a shot at F8.





    Much less visible.
  2. Promit

    Promit Mu-43 All-Pro

    Jun 6, 2011
    Baltimore, MD
    Real Name:
    Promit Roy
    Can you elaborate on how to "enhance" to get a feel for the dust level on the camera? I can't find the CSI button in Lightroom 4.0.
    • Like Like x 1
  3. sprinke

    sprinke Mu-43 All-Pro

    Apr 5, 2011
    Pasadena, CA
    Real Name:
  4. MartinOcando

    MartinOcando Mu-43 Regular

    Apr 3, 2012
    I'm also interested in your technique to enhance the dust.
  5. GaryAyala

    GaryAyala Mu-43 Legend

    Jan 2, 2011
    I'm impressed you cut up a credit card.

  6. RobWatson

    RobWatson Mu-43 Hall of Famer

    I don't know what was done but things that are good for 'dust enhancement' are a simple adjustment of the black and white levels. More exotic things like unsharp masking + contrast adjustments will really bring up the dust.

    A really strong 'dust' enhancement is to create a blurred image from the original and use it as a flat field correction back onto the original. Then use a very aggressive contrast setting or histogram equalization and you will see things you never believed could be there!
  7. Luckypenguin

    Luckypenguin .

    Oct 9, 2010
    Brisbane, Australia
    Real Name:
    In Photoshop I think that you select "Auto Levels" to enhance the dust. Lightroom may have something similar.
  8. lenshoarder

    lenshoarder Mu-43 All-Pro

    Nov 7, 2010
    To enhance the dust, I did the simple thing, an auto level. By it's nature, the image to see dust on the sensor is very uniform unless you have really really bad dust. So as the previous poster said, the black and white levels just need to be adjusted. Auto level takes care of that nicely.
  9. rdearth53

    rdearth53 Mu-43 Regular

    Feb 4, 2012
    Wadsworth, Ohio
    Haha! I love the subtle humor there. For some reason, it really got me. Thanks!

    Sent from my Galaxy Nexus using Tapatalk
  10. phrenic

    phrenic Mu-43 All-Pro

    Sep 13, 2010
    Nice..I'm not sure I would be so brave with my cameras, but good to see they can hold up to a good scrubbing.
  11. thearne3

    thearne3 Mu-43 Top Veteran

    Jan 28, 2010
    Redding, CT USA
    ...and dust really shows up in pictures when you venture above f11 - that's when I make the decision to break out the cleaning equipment! Dust becomes fairly large grey spots when the aperture is small (high f-stop).
  12. lenshoarder

    lenshoarder Mu-43 All-Pro

    Nov 7, 2010
    Here's an update. I cleaned the sensor some more. I've come to the conclusion that pec pads aren't that good for cleaning sensors. I know many websites sing their praises but I didn't find them very effective at removing anything. They just pushed everything around.

    The tool I've settled on is squares cut from a plush microfiber cloth rubberbanded/taped onto the end of a Japanese chopstick. These chopsticks taper at the end which makes it easy to reach the edge of the sensor.

    Here's the result of the first try at another cleaning. Once again, F22, long exposure and auto leveled to show the dust.


    Much cleaner than it was.

    I tried again and got this.


    I don't think it was any more clean. At a certain point, I'm just moving the dust about. I can't even see any of this dust on the sensor. So it's hard to track down and try to wipe it away.
  13. TDP

    TDP Guest