MP240 white pixels / hot pixels

[jev_dk]

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Hi all

I recently purchased a mint MP240 and in some situations I see white pixels in my jpg files - in the corresponding pixels I see dark red pixels.

In normal photos I never see them. To see them I set the camera around ISO 640 then shoot a scene with strong light in the left and a white wall (that becomes dark) to the right. Like the image attached.

There will be several white spots even viewing 1:1

Leica took it back and serviced it and may and may not have mapped out some pixels but problem is still there.

I borrowed another MP which exhibits almost the same behavior although different place in the dark area.  

Anyone here that can recognize this?

 

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[adan]

Have you tried shooting in .DNG? or .jpg + .DNG?

I rarely use .jpg, but it seems to me I have seen a few hot pixels in those (or in the .jpg preview images for DNG files), that are not present in the full .DNG version of the same picture.

[tom.w.bn]

vor 2 Stunden schrieb adan:

Have you tried shooting in .DNG? or .jpg + .DNG?

I rarely use .jpg, but it seems to me I have seen a few hot pixels in those (or in the .jpg preview images for DNG files), that are not present in the full .DNG version of the same picture.

Most DNG converters take care of pixel issues like this. I don't think that there are cameras without at least 1 pixel that is not operating optimal.

[jev_dk]

17 hours ago, adan said:

Have you tried shooting in .DNG? or .jpg + .DNG?

I rarely use .jpg, but it seems to me I have seen a few hot pixels in those (or in the .jpg preview images for DNG files), that are not present in the full .DNG version of the same picture.

It happens when shooting DNG + JPG and is very visible in JPG files, then if you look for them they are present in the DNG as well.
It's not a big issue I am just curious why this happens in such an expensive camera - never seen anything like it in Nikon, Canon, Fuji etc. 

[adan]

To avoid a lot of repitition, this thread covers the subject of hot or dead pixels to the nth degree:

Key point is that silicon is silicon, and at the level of quantum physics, new pixel defects will be created throughout the working life of a sensor simply by existing in a universe filled with cosmic radiation (or heat/infrared - I've had an M9 acquire a new stuck pixel just by leaving it in a hot car at 45°C for an hour). The M(240) manual, along with every other Leica digital manual, specifically warns that a certain number of defective pixels (out of 18 million or 24 million) are normal, even brand-new from the factory.

There is no "expensive Leica silicon" nor "cheap Nikon silicon" as far as the raw material is concerned. It is all 99.9999999% pure when the chip fabrication begins.

BTW - if you see 10 such pixels, that is a failure rate of 0.0000004166667% (10/24000000).

Another key point is that unless one has used a statistically-significant sample of Leicas, Canons, and Nikons (at least 1000 Leicas, and 10000 Canons or Nikons), saying one has "never seen" stuck pixels on a Canon or Nikon is not serious evidence.

I've had seven digital Ms, M8 through M10. One acquired a couple of stuck pixels, two showed evidence of mapped-out stuck pixels, four never showed anything. But even seven cameras do not make a statistically-significant sample - it was pure chance that I happened to get those particular seven cameras out of the tens of thousands made.

The good news is that one no longer has to physically send in a digital Leica to have hot/stuck pixels mapped out. Simply email Leica service with a complete .DNG file showing the bad pixels, and Leica can email you back a new personalized copy of the current firmware, with an updated "bad pixel map" - the camera will then ignore the data from each hot (or dead) pixel and fill it in by interpolation from the next-door pixels.

[jev_dk]

@adan thanks for this summary (I did my research prior to posting though) This topic is not about dead og stuck pixels as they do not appear in the same place. It’s meerly about the JPG processing combined with some pixels behaving differently than they should (?)

Only from M10 remote pixel mapping can be done so my MP needs another trip to Wetzlar but as pixels seem to be random in their behaviour I can’t see how they can be mapped out

I suspect this is more to do with ISO combined with certain lighting and I am still asking for other M owners that have experienced this.

[EdricBF]

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My M9 shows two red pixels every time I shoot RAW+JPEG, in both files. If I set for just RAW, the DNG file shows nothing... Weird behaviour, IMHO... No more DNG+JPEG for me... lol