X type spots, on the sensor?

[emipuscas]

Hi guys,

I have an issue with my EOS 6D, beside some spots on the sensor, the ones that give dar areas on the image, of diffrent sizes, I have several X type dots, like the two attached and am very curious if you ever saw anything like it.

I will get my sensor cleaned at a professional center but from my logic these look like things that don't get solved by a cleaning procedure, and are rather some electronic faults.

I have some pixels that are turned on on some specific colours, like blue or purple, but these X pixels are something I never saw before.

So, if you know, please tell me if there is another sollution, other than replacing the sensor - wich might not be worth the money for this camera.

Thanks in advance.

[Waddizzle]

The 6D is a nice camera.  I would advise you to pass on the “professional cleaning center.”  I would only let Canon check it out.

[tmc784]

Yeah, let the pro check and clean.

[MikeSowsun]

What ISO were you shooting at? How long was the exposure?

Those are called "hot pixels" and are quite common with most cameras when shooting at high ISO or long exposures. (sensor gets hot)

Cleaning  your camera won't get rid of them. Some people say you can get rid of them by taking the lens off, and doing a manual sensor clean for about 30-60 seconds with the body cap on. 

[govindvkumar]

This looks like a interconnecting cable issue. Tou cacn get it to the service centre and get repaired.

[Peter]

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@emipuscas wrote:

Hi guys,

I have an issue with my EOS 6D, beside some spots on the sensor, the ones that give dar areas on the image, of diffrent sizes, I have several X type dots, like the two attached and am very curious if you ever saw anything like it.

I will get my sensor cleaned at a professional center but from my logic these look like things that don't get solved by a cleaning procedure, and are rather some electronic faults.

I have some pixels that are turned on on some specific colours, like blue or purple, but these X pixels are something I never saw before.

So, if you know, please tell me if there is another sollution, other than replacing the sensor - wich might not be worth the money for this camera.

Thanks in advance.

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Those are dead, hot or stuck pixels and easy, if you shoot in raw, to fix in post.

[Ray-uk · Accepted solution]

As has been stated these are hot, dead or stuck pixels. The centre of the mark is the pixel with a problem, the reason they look star shaped is because during the conversion to JPG the software is trying (and failing) to average out the effect by adusting the brightness of the surrounding pixels. If you shoot in raw then you will see they are just a single pixel and not a cross.

[emipuscas]

Hi. The ISO of the affected shots varries between 1000 and 5000, but the problem is the same.

The answer that I accepted as sollution said that that is a center pixel, but in jpg conversion it tryes to solve it out, and as a result I have the X marks on the photo.

I will get the sensor cleaned, for some other dirt spots, and will keep solving these in post, until I get another camera.

I have another identical 6D, a rather younger sibling, and that one has no such issues 🙂 - this is my backup camera.

Thank you, and thank all for the help.

[kvbarkley]

I am not sure about that, it could also be a de-mosaicing artifact.

[Ray-uk]

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@kvbarkley wrote:

I am not sure about that, it could also be a de-mosaicing artifact.

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I would have thought if the X effect was due to to de-mosaicing it would appear in raw files also. I beliieved the de-mosaicing was carried out before the data was put into the raw file but I must admit that I don't know enough about the format of the raw data so could well be wrong.

On reading my original reply it suggests that the conversion to jpg actually aims to lose the faulty pixel. I didn't really mean to imply that.

What I should have said was that the conversion to jpg involves compressing the data to a smaller file size and in doing so it averages out adjacent pixel values and one individual bright pixel will have the surrounding pixels adjusted to blend in, this causes the pattern that the OP is seeing.

To the OP,

All digital cameras will show faulty pixels at some time, even new cameras. It is not worth replacing a perfectly good camera for this problem unless the number of faulty is pixels is so severe that it is really troublesome. A lot of cameras have the facility to map out these problem pixels so that they don't appear.