Symptoms. When looking at the images on a computer, the whole image has horizontal lines through it. The lines are approx. 1 px wide and 1 px apart. One line is bright, sometimes near white but mostly still containing image information. The other line contains normal image information. Due to the bright lines, the images make the impression of being overexposed. When looking at the camera's LCD before taking a picture, there are no horizontal lines (but this can be explained with the low zoom level also). However, there are also no bright lines when using the video function of the camera. All of these have been confirmed by me in one case. Other people report that these lines are only present in images taken in bright light conditions, while not present in images taken in darker light conditions.

Tests. In the current case, a Casio Exilim EX-S770 had these symptoms. I first thought that the CCD sensor is bad, so I got a second (working) sensor and a second camera and made some tests. The results were enlightening, as they showed that the error is located in the lens, not the camera's mainboard or CCD sensor. Basically I used the lens of the non-working camera and exchanges everything else in all combinations, and always had the horizontal lines symptoms. Like this:

lens sensor camera body lines? autofocus?
original original original yes working
original original replacement yes non-working
original replacement original yes working
original replacement replacement yes working

On a side note, no changes to the combination of original lens and sensor were made when moving it from the original camera (autofocus works) to the replacement camera (autofocus does not work). Which means that a defective autofocus can have a cause on the mainboard (or maybe in missing adjustment settings to a new lens?).

Diagnosis. The mechanical shutter does not work. This can be recognized  because there is no shutter noise (disable sounds for that), no shutter movement when triggering a photo and looking into the lens, and because there are no bright horizontal lines in videos (where no mechanical shutter is used). Also, the error could not be fixed by exchanging mainboard or CCD (see the test list), so has to be in the rest of the objective (shutter or aperture).

The diagnosis "defective shutter" for these horizontal line symptoms is given in the mydc.tw knowledge database, including example images (note: automated translation to English!). They also gave me the important hints how to diagnose the defective shutter. The most in-depth discussion, including other possible causes like apterture or (rarely) the CCD indeed, is given in monitor.net.ru thread 138505 (English translation). It seems that Russians are really great electronics hackers – just look at the monitor.net.ru digital camera forum index.

Web search notes. The best Google search keywords are: digital camera "horizontal lines". There are many uneducated forum posts about this topic, where people suggest that it is a faulty memory card, faulty card reader, bad USB cable or faulty CCD sensor. Do not listen to them; there are no reports that these tips did help.

7 thoughts on “What can be the reason for horizontal lines on images of a digital camera?

  1. Hi Matt, i am probably reading your post a liitle late but I am having these horizontal lines on the images on my Canon A470 only if I snap in Normal mode. Macro mode is okay. Video shooting is also okay.
    Does this phenomenon point to defective shutter as well?
    Thanksl.

    CY

  2. ertorque: Honestly, I don’t know. But you can test by looking out for shutter noise and shutter movement when taking images in low light conditions resp. with long exposure times (as that will make the shutter movement better visible) and watching straight into the lens.

  3. My camera is showing those lines.
    It shows like what you desscribed here. Live on still images not not on movices. and still images is overexposed.

    I have been doing lots of test and I have notice if I change settings to save image to 03M there are no lines, at 6M there are lines.
    Interestingly at 2M it show “circles”, but if I change zoom level “cicles” gets zoomed too. and eventuly it turned into lines.

    Can you check if your camera has this behaviour too?

  4. iMini1D, I can’t test with my own camera because I repaired it already. But having lines only on high resolution images (and on high zoom levels) is pretty much what I would expect. Because when you set anything lower than your (6 MPx) max. resolution, the image will get scaled down in the camera, which will hide the “every second line” white lines. Or, depending on how much it gets scaled down, it will result in funny patterns (an effect that is probably similar to the Moiré patterns).

    So, if you have the “every second line a white line” phenomenon on the highest resolution images, I believe it is the same symptom that I had.

  5. Great post, enlightened what a problem could be here, and stopped from hunting for replacement CCD on right time.

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