D7100 'streaking'

Started Apr 7, 2013 | Discussions thread
mosswings
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Streaking is one of several image-dependent sensor artifact mechanisms
In reply to Horshack, Apr 12, 2013

Unfortunately, it is rather ill-understood or part of the most closely held technological know how of the sensor manufacturers, as it is one of the key differentiating features of their products.  I was able to find a few general articles on the subject, but the pictures in this otherwise useless blog article from a machine-vision camera manufacturer are very interesting as they look a lot like what we're seeing:

http://info.adimec.com/blogposts/bid/88624/CCD-vs-CMOS-Image-Artifacts-to-Consider-with-CMOS-Image-Sensors

Column noise, line noise (streaking), and black level shift stem from imperfections in the dynamic bias and cell reset circuitry, it seems.

This article from the 2009 Intl. Image Sensor Society Conference discuss other such dynamic pattern noise mechanisms. In particular, what the authors call "smearing" can be traced to a cell biasing voltage that is slow to settle:

http://www.imagesensors.org/Past%20Workshops/2009%20Workshop/2009%20Papers/073_paper_purcell_invited.pdf

The next article is pretty fabrication technology geeky, but shows just what incredibly complex dynamic adjustments are going on at the pixel level to yield the ultra low noise levels we are enjoying.

http://cdn.intechopen.com/pdfs/17221/InTech-Image_artifacts_by_charge_pocket_in_floating_diffusion_region_on_cmos_image_sensors.pdf

imagesensors.org, the website of the IISS, has a wealth of papers on low level electrical and fabrication design and measurement.  It rather boggles my mind what imaging engineers are doing these days.

However, what this suggests to me is that the effect we're seeing is happening at the lowest levels of the sensor circuitry...and because its geometry dependent, it is not amenable to postprocessing tricks.

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