My D70 has a dead pixel

I just noticed my D70 has a dead pixel. I was letting my nephew use

my D70, which is now my backup camera. While explaining the basics of

exposure, we set the camera to manual and deliberately underexposed

some frames by several stops. We were also shooting in JPG normal

since these were just practice exposures and there was no need for

large files. While viewing the underexposed photos on the monitor, I

adjusted the levels on one and was shocked when I saw an obvious

blown pixel and a trailing line below it.

 

I then reviewed some photos I shot with the D70 a few weeks ago that

were properly exposed and shot in NEF. While it took some effort, I

was able to locate the dead pixel in those photos as well.

 

I can live with the dead pixel (and correct for it in PS)if it's not

likely to get worse and is barely noticeable with a properly exposed

image shot in RAW. My questions are:

 

Should I expect this problem to get worse or the sensor to exhibit

more of these in the future?

 

Is there anything that can be done to prevent this problem from

happening with my D2X?

 

If I decide to have the D70 repaired, which is now out of warranty,

any idea what the cost might be?

are you sure is a dead pixel and not dust?

 

just a thought

I'm pretty sure that's what it is. That said, the sensor could use a cleaning. Here's what I'm referring to. This is a crop (obviously) of a section of sky from the image that was at least 2-3 stops underexposed and after a levels adjustment in PS. In another, properly exposed photo, the dead pixel is barely visible and there is no visible trailing line.<div></div>

It seems a definitely as a dead pixel.

Yup, same thing in my D2H, sans the long thin line. It's going back for servicing ... as soon as I can let go of it. I seem to keep needing it. So I keep telling myself "Just one dot with the dust tool ... then 299 more photos to go ..."

 

Apparently it's nearly impossible to guarantee these things won't have a dead pixel or so. Most manufacturers of LCD computer monitors say up to seven dead pixels is acceptable - the *them* - and isn't considered grounds for return, exchange or service under warranty.

 

At least digicam makers seem to be willing to try to tackle the problem. Olympus dSLRs are "self-servicing". They remap the area to work around the dead pixel. Other brands have to be sent into a service facility to have this done. I think Olympus has the right idea.

 

Nikon recently acknowledged unspecified problems with some D70, D2H and N55 bodies and announced it would repair these beyond the warranty period. I don't know whether this is intended to include dead pixels but it's worth asking.

Can anyone explain the line (curiosity)?

Re the line:

 

in semiconductors terms, each bit (a pixel is 3 bits of different color) is accessed through bit and word lines (horizontal and vertical). If a bit is dead, and causes an electrical short, it can change current distribution in the the whole line accessing it (either bit or word line). In this case, it seems the green bit is causing an electrical short for all green bits up to and including the actual failing bit, causing false readings for those bits...

 

The actual physical failing mechanisms are numerous, and can lead to single bits, double bits, single or partial lines, doubles lines... for camera sensor, with 3 or more bits per pixel, and interpolation with neighbour bits for color optimisation, I would expect all sorts of potential image artefacts.

 

I am no expert, just a little familiar with semiconductors.

It is possible that Nikon has that "re-mapping" too as Lex said.

I read the same thing in a KM forum, but I did not think it was true.

Laurie do like this: change you date in your menu, one month ahead.

Turn the camera off and on again it is possible (and with little luck) that Nikopn do re mapping and after one month this work.

Check now if that helps, if not, mmmmm. Service?

 

 

Good luck.

I am just saying this as a matter of pracaticality and as a potential money saver so do not take it otherwise.

 

Wait till your D70 gets BGLOD, send it to Nikon and everything will get fixed at once.

"If I decide to have the D70 repaired, which is now out of warranty..."

 

Perhaps it is covered under the implied warranty of merchantantability under the Uniform Commercial Code which is the law in many states. The warranty applies to all products sold by merchants for a reasonable amount of time absent a conspicuous disclaimer BEFORE the sale is made is made. For something as expensive as a digital SLR, it may be worth pursuing.

Thanks for the responses! Vivek, Before I read your post, I was already on the Nikon site reading their policy on service for GBLOD. You now have me hoping for something I've dreaded. Is there anything I can do to hasten it? Just my luck, I have the one and only D70 that will never suffer from that problem.

 

Seriously, as I said, on a number of properly exposed images shot just a few weeks ago, I had to look pretty hard to find the spot. While I'm not happy it's there, I can just get rid of it along with all the sensor dust etc. in post processing. My concern is that this is a sign of things to come.

 

Does one bad pixel necessarily mean more are to come?

 

Will the evidence of this bad pixel become more apparent with time?

Laurie, I really do not see any straight connection between the dead pixel and the BGLOD. That has different symptoms. Do not know if your camera will succumb to it either. Since Nikon does not say which batches of their D70 are prone to BGLOD categorically, every camera is suspect. If it happens sooner than later, you are in luck, in a strange way!

Vasilis - The bright line is actually caused by the 'hot' pixel: Since the signal of every pixel located below the hot pixel must be transferred across the defective pixel, their values are contaminated by the extra charge that they pick up when they cross the bad pixel, and as a result, they appear brighter.

 

Laurie - The bright pixel in your D70 has been in the sensor since it left the factory, and the defect level must be within the manufacturer's tolerance specs. Since these defects are not caused by normal use and typically do not get worse over time, I wouldn't worry about it.

Vivek, My D70 is a fairly early model. I've used and abused it. Since it hasn't suffered GBLOD yet, it probably won't. And that's fine with me. While my D2X gets most of my attention these days, it would seem odd to send the D70 out for repair and not have it available. I know that sounds weird but I really do like that camera. It has served me well.

 

Berg, Thanks for explaining the line. I hope you're right that the problem won't get worse. I'm not so sure it was there from the time it left the factory. I've looked back on some older images and can't find the dead pixel. I'll see if I have any underexposed frames that escaped deletion and have a look at those.

 

I'll take the camera out this weekend and shoot it at extremes (under/overexposure, long shutter speeds, different quality settings, etc.) and see what happens. If the results are interesting or shed any light on this pixel problem, I'll post them.

Laurie, if my experience with my older Olympus P&S digicams is indicative of what we can expect, yup, dSLRs are likely to develop more dead pixels as they age.

 

My Olympus C-3040Z (about four years old, maybe five) has quite a few dead pixels, most of which show up only on underexposed photos. It started out with only one or two but now has a liberal sprinkling of 'em.

 

I'm just hoping that dSLR makers don't take the attitude of makers of some LCD monitors and TVs that dead pixels are, to put it bluntly, tough luck for consumers.

Laurie - The 'hot' pixel that bothers you will be more noticeable in shots taken under dim light, at warmer temperatures, higher ISO settings, and longer exposure times. Unless you take these conditions into account, it will be hard to tell if the defect was always present in the photo.

The person who suggested changing the clock one month ahead did not state whether to leave the clock ome month ahead forever. I don't understand how his could do anything. Could they please leave more detailed instructions? Thanks for suggesting a solution.

Laurie - When I crank up my D70 to ISO1600, I get three red blobs. I know they're not there during lower ISO shooting but it's something I've had to watch for. I never noticed it until a year later and I don't shoot at that speed much, so I blow it off. I'll test more comprehensively next time. Dead LCD pixels are different than CMOS/CCD because LCD display has no impact on the stored image and that's why it's acceptable to have some dead. I have a stuck red on my $2400 laptop. I don't care. But dead pixels on the capture device is a whole different story. One isn't acceptable to me there.

Test at low & high ISO before your basic return period is over and you should be good.

Hi Laurie,

 

Was this problem resolved?

 

I have an exact same problem with my D70. Nikon Svc says my camera is out of warrant (more than a year) and they are asking for good amount of money to repair this..

 

Any information on how to get it fixed or how to live with this using photoshop or any other software will be greatly appreciated.

 

thanks

Keviv