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Old Nov 27, 2002, 8:15 AM   #1
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Default Hot Pixels - How much of an issue for normal consumer?

I have read about issues with hot pixels, particularly with the higher 4-5 mp cameras?

For the normal consumer user, how big and frequent of an issue is this? What do you do if you get hot pixels? As the camera gets older and more use, does it start getting more hot pixels? Do all high mp cameras eventually get hot pixels?

Are hot pixels an issues with 3 mp cameras?
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Old Nov 27, 2002, 8:38 AM   #2
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I've had 4 digicams sofar. Only one of them had a hot pixel - that was the Coolpix 990 from Nikon. I then knew nothing of digicams so I took it to salesman - he send it to Nikon. 2 Days later I had my digicam back - with no hot pixels.
I called Nikon and asked, what they did. They answered, that they simply installed a new firmware - that it! So if you digicam has a new firmware - just upgrade or get one.

The more the pixels - the bigger the chance for getting a hot pix - I guess.
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Old Nov 27, 2002, 8:54 AM   #3
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The technique used on lower cost broadcast ccd's is to take the failed ones not suited to high end cameras, map the faulty pixels and put error concealment into the software so the clone pixel looks like the average of 2 pix either side, and hope you won't notice the difference.

Consumer digicams are likely to have a number of faulty pixels in chips, dearer cams may get the cream of the chips, the rest get error concealment! So when you can find out how to turn off error concealment you'll see the truth.

Sounds to me, this is just what new firmware did - re-calibrated the ccd!
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Old Nov 27, 2002, 9:05 AM   #4
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You may be right. But I dont consider Nikon to be a lowercost digicam and the technique you described seems a little odd to me.
Often - most often - hot pixel arrives after some time...
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Old Nov 27, 2002, 9:20 AM   #5
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We all like to regard our brand as something special, but production yield is about physical processes and commercial reality. The marginal chips are graded and do end up somewhere!

Specifications and requirements for professional and business use are often very much higher than what you might be used to. The only problem is you couldn't afford the product as a consumer.
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Old Nov 27, 2002, 9:49 AM   #6
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You are right! But I dont regard i.e Nikon as something special.

I mean...Nikon is just the digicam I have right now - maybe another tomorrow.

However I think that some bigtime firms, like canon, nikon, olympus... cant affort to send "broken" products on the street - I would like to think that the will leave those bad chips for other small time firms. Who knows...
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Old Nov 27, 2002, 11:53 AM   #7
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Yes, I think we have the idea now. The products are not really broken, they're just - well- fit for 'consumer' use, with masked pixels in zones you might not notice. The central zone is always most critical, so one might expect better brands to be intolerant of errors here.

If the ccd's are actually deteriating over time, manufacturers will first look at software to error correct, (sorry re-calibrate) when you first switch on. So any problem will remain invisible for a long time. Then, as higher ccd yields are achieved and life issues are understood, the chips will have improved.
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Old Nov 27, 2002, 11:55 AM   #8
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In the "early days" of digital photography, hot pixels were quite prevalent. Nikon 950's were notorious for this. From my understanding, Nikon just "mapped out" the offending pixels. One can easily do this with post processing S/W. I don't think cameras with hot pixels are necessarily "broken", the photos they generate just need a little more post processing. I think many of the new cameras come with firmware that looks for hot pixels and so are able to hide them from view as they appear.

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Old Nov 27, 2002, 12:45 PM   #9
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Quote:
production yield is about physical processes and commercial reality
This is a real world issue: one pixel out of 5Mp is 0.2x10E-6 defect a practical limit... They have QA departments with CPk measurements to optimize theses processeses, but a challenge for most microelectronic manufacturers. Flash cards too have build in defects from the factory and increase with use that are continually masked out by ECC, but most users don't realize this either!

It'll be a magnitude higher when the next generation CCD appear... :lol: :lol: :lol:
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Old Nov 27, 2002, 1:13 PM   #10
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Yes NHL, but after that we're all gonna shift to CMOS - wonder if the problems continues with that!
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