Hot pixels question! (semi-urgent)

[Val]

In my experience, there will always be hot pixels - if not now, then soon as a sensor ages.

Yes, thats what im very interested in. But how long does it usually take for a hot pixel to appear? If it takes like a year of good use then surely its worth it to replace the camera?

 

[astrostu]

Yes, thats what im very interested in. But how long does it usually take for a hot pixel to appear? If it takes like a year of good use then surely its worth it to replace the camera?

I honestly don't know, and I think it depends upon the quality of the sensor and definitely upon its use.

 

[Sw1tchFX]

why dont you just clone them out?

 

[Garbz]

Err unlike displays such as LCDs, hot pixels on a CCD are not a manufacturing defect. It's simply a function of which pixel dies first when you push it a bit.

If you had a hot pixel at ISO100 at anything faster than 5-10 seconds then it may be a cause to send it back. But if you start upping the ISO then things get worse.

If you want to know what I mean why not crank it up to ISO800 and take a 30 second exposure with long shutter noise reduction off and start counting dead pixels then.

Btw since it is always the same pixels which die at any given shutter speed / ISO / temperature, this is all long exposure NR fixes. It simply takes 2 exposures at the same settings, except one with the shutter closed and then outputs the difference between the two to kill dead pixels.

My advice is not to worry about it. Sending the camera in is more trouble than it's worth in my opinion, and all they will do is map the pixels so that they can't produce that colour again. So when you take a photo of something bright red it'll have a dark spot.

 

[Val]

Bah you guys totally confused me

 

[Sw1tchFX]

Bah you guys totally confused me

basically don't worry about it, it's more trouble than it's worth for something that can easily be cloned out and hardly ever seen anyway.

 

[soylentgreen]

I had an annoying hot-pixel on my 40D about a month or so back. I removed the battery and dishcarged the device over-night and it has not recurrd since. Worth a try. Canon said I could send it in for service, but that will take 2-3 weeks. With no back-up body as of yet, would be quite inconvenient. Though cloning and healing is an option, on a few pics that fine...but batch processing the couple of hundred frames I take everytime out would be a pain in the @$$.

 

[Val]

How do you discharge a camera?

 

[soylentgreen]

Take out the power source for an extended period. I had mine out for about 18 hours though the Canon rep said overnight sould be fine. This removes any electrical impulses in the device and allowed the sensor to discharge completely. Worked in my case anyway.

 

[Val]

Ah ok. I though maybe you need to do something special. I left it over about 10 hours with no effect.

 

[JerryPH]

Not sure about D300s but to completely discharge a D200 takes weeks. I just slapped in my batteries for the first time in about 2 weeks. My custom settings were there and the date/time was accurate.

 

[astrostu]

Not sure about D300s but to completely discharge a D200 takes weeks. I just slapped in my batteries for the first time in about 2 weeks. My custom settings were there and the date/time was accurate.

There's a backup battery.

 

[Val]

Went to the shop. They gave me another camera... it also had 2 dead pixels and also one on the LCD ill keep mine thanks...

 

[Antithesis]

Went to the shop. They gave me another camera... it also had 2 dead pixels and also one on the LCD ill keep mine thanks...

You must have miserable luck. I've never noticed any problems on my d80 but now I'm tempted to shoot a white surface and pore over it for dead pixels.

 

[Garbz]

You must have miserable luck. I've never noticed any problems on my d80 but now I'm tempted to shoot a white surface and pore over it for dead pixels.

If you've never noticed why bother looking? That's a problem in itself. People turn into bean counters. So many "photographers" today (and I'm talking about others, the people in this forum are quite good in this regard most of the time) spend more time looking at the image zoomed at 100% complaining about noise, or lack of sharpness, or some other technical equipment flaw preventing them from being the next Ansell Adams. If you go looking for flaws you'll find them. I would prefer to just keep taking pictures.

Val said it best in another thread. "I don't take pictures of graphs," I'm glad to see Val has chosen to ignore the "problem" and get back to taking photos.