Dead Pixies....MkII N

Not happy.....!! today I found a couple of dead pixels on my CCD. I've only had the camera for around 3 months.... anybody else had this problem ? Will Canon replace the camera or the CCD ?

I also noticed that there is a bit of a front focusing issue with it, I'll get Canon tech to address this issue as well....

Thought I'd just mention that !! let off a bit of steam as well...hope you don't mind.

Regards,

PS, my wife calls them pixies....

Barry Johnston said:

Not happy.....!! today I found a couple of dead pixels on my CCD.

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Define "dead".

Dead=no response despite exposure.
Hot=(very) high even without exposure.

And then there are pixels that are systematically darker/lighter than they should be, given the amount of exposure compared to surrounding pixels in a uniformly exposed area. With the exception of dead/hot pixels (actually it's the sensor elements, usually first visible after Bayer CFA demosaicing), the visibility of them increases with exposure time.

I've only had the camera for around 3 months.... anybody else had this problem ? Will Canon replace the camera or the CCD ?

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Did you check for this when you got the camera, and they where not there then, or did they manifest themselves only recently? Also, are they clustered together, or spread out over the sensor array?

Usually the aberrant sensels get "mapped-out", so they will be treated as having an average response of surrounding sensels.

I also noticed that there is a bit of a front focusing issue with it, I'll get Canon tech to address this issue as well....

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That's what they are there for, although they may be hesitant when the amount is within 1/3rd DOF specifications, so be nice to them.

Thought I'd just mention that !! let off a bit of steam as well...hope you don't mind.

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I feel your pain ..., and it's like they get more prominent as you look, because now you know where to look.

Bart

Dead Pixels....

Hi Bart,

Actually, I did not see them before, probably because I was not looking for them. They are 2 at present, I have not searched the whole CCD, but they are completely white spots in a completely dark surrounding. They are in the same place on every image. One of them is completely white, while the other lacks magenta I think.

Regardless, will take it to Canon as soon as possible and ask them to sort it out.

Thanks or your reponse.

Barry.

The best of luck with it Barry.

The pixels is an easy fix. Canon plugs the camera in to their service computer and map out the offending pixels.
The focus is another thing altogether, could be the camera or lenses. You need to bring both the camera and the lenses in.

PS CMOS not CCD ;-)

Thanks..

Hi Jorgen,
Thanks for the info. I was concerned that they would have to replace the CMOS, but if it is an easy fix, that makes me feel a lot better.

Re. focusing, I will take the lens in as well, but do you know, if they adjust it, will affect my other lenses. I have an 85 1.2, whch seems to be perfect.. I am concerned if they make an adjustment it will affect my other lenses.
Do you think I should do some advanced testing before I take it in, I have not done that yet, but probably a good idea.

Thanks,

Barry.

I've never done any real focustesting myself, but there are several testing charts around the net. And there´s the batterie-method, take 5 AA batteries, put them next to each other, on a 45 degree angle, and focus on the middle one.
I think, that you need to take all your lenses in (Canon lenses), so they can match the camera with all the lenses.

Jörgen Nyberg said:

I've never done any real focustesting myself, but there are several testing charts around the net. And there´s the batterie-method, take 5 AA batteries, put them next to each other, on a 45 degree angle, and focus on the middle one.
I think, that you need to take all your lenses in (Canon lenses), so they can match the camera with all the lenses.

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Actually the lenses are calibrated to a lens specification. Similarly, cameras are calibrated to a camera specification. The cameras and lenses are not adjusted to play with each other.

One thing I'm not certain of is "if" Canon will adjust a lens to a camera (or vice versa) at the request or insistence of the customer; I seriously doubt Canon would do it but a call to a service center would get a quick answer.

Regards,

Joe Kurkjian

No, I know that they aren´t really adjusted to each other. But there is a certain headroom, in both the camera and lens specification, so if one adjust the camera, they can end up at the opposite extreme ends of the scale, and one lens that was fine before can suddenly be sligthly off.

Canon will certainly do it, but maybe not for free. I know several people here in Sweden, who has had their camera and lenses calibrated, but at a cost.