Applied Color Science compares "black sun" effect between Omnivision OV5610 and Micron MT9P401, both 5MP. It occurs when a camera is pointed at a scene with a very bright, very concentrated source of light like the disk of the sun. Some CMOS sensors show these super-bright areas as dark, rather than saturated bright.
The result of the comparison is that MT9P401 sensor is free from bright image inversion, while OV5610 suffers from it. One needs to note that Omnivision's sensor belongs to 2.8um pixel generation while Micron's is 2.2um. The newer Omnivision sensors might behave differently. The site also has a simplistic explanation of why "black sun" happens.
It IS surprising that Omnivision has not fixed this ancient problem in their sensors. The problem was identified and solutions proposed over a decade ago. It really has little to do with process technology or generation.
ReplyDeleteApplied Color Science needs to work on their explanation some more, that is for sure.
-EF
Actually, 1.75um generation of Omnivision sensors, such as OV5630/33, is said to have "support for black sun cancellation". I don't know what it means.
ReplyDeleteOmnivision not able to cope with full-well when decreasing pixel size and reset/sensing node issues? Well, time to go back to silicon science and forget about pure business and communication.
ReplyDeleteFirst, the article talks about Omnivision's 2.8um pixel sensor. I think Omnivision addressed this problem in its more recent designs. Second, Omnivision is one of the biggest image sensor companies. It's among a few having positive cash flow. I would not neglect its skills and knowledge accumulated over many years.
ReplyDeleteOV5610(1/1.8") is a really old product, elder than MT9P401(1/2.5") <<-- the 4th generation.
ReplyDeleteSo... it is a weird report - not apple to apple.
From Omnivision website, we can't find OV5610 any more, science this product was so old.
ReplyDeleteIt is so mean to do this comparison.
has anyone seen a circuit suggestion to solve this problem?
ReplyDelete