Testing an M8 - Hot Pixels

[2Ms]

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I bought a used M8 recently and I am currently checking it to see if it is all working properly. However, I'm not entirely sure how to check if the sensor has any hot pixels.

 

I've done a search and one piece of advice i've come across is to take a photo with the lens cap on, with the ISO set to 1250, the shutter set to 1/30 and shooting DNG files.

 

The resulting image appears to show two bright blue hot pixels, but they disappear after a few seconds and are replaced with what appears to be noise (smaller and duller blue and white dots which cover the entire image). I think I read that this is the camera processing the image but I'm not sure.

 

I don't seem to be able to see the hot pixels in Capture One either. Nor do I appear to have any vertical lines at the moment.

 

Do I have hot pixels?

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[GeebeeWien]

Every sensor has hot pixels when use for long time exposures...

 

What you see on the display initially is the "primary exposure", so the actual photo you took. What you see after a few seconds and in lightroom is a combination of the actual exposure + one dark frame, which helps to reduce noise and pixel errors of long time exposures.

 

Gekrg

[jippiejee]

That's quite normal and not something to worry about. Lightroom automagically removes them in the develop mode.

[2Ms]

Thanks for the replies.

 

I should have made the question more specific.

 

What I wanted to know is whether the existence of these hot pixels is going to cause problems later on, namely, a remap or in a worst case scanrio, a sensor swap.

 

I'm aware editing programmes can remove these but my concern is that an expensive bill is on the horizon; or at least that is what I have read.

 

Posts on this topic often say software can remove the defects but then in the same thread people say a remap or sensor swap is required.

 

Are these people saying there will come a point when software will no oonger correct these defects?

[Dougg]

1/30 sec exposure is not long enough to cause the camera to make a dark frame subtraction. So your procedure was fine in that respect.

 

As mentioned, it can be a problem to view the resulting file with overhelpful software that "fixes" the problem before you can study it! My M8 came with an older version of Capture One which did nothing to hot/dead pixels or vertical lines, so I was able to discover the line on my camera once I was aware others had found it on theirs. The image has to be examined at 100% scale to see this.

 

I don't now recall if the defects are visible in out-of-camera JPEG files, but certainly in TIFFs. I still use a catalogging/editing shareware program on my Mac called GraphicConverter, which will open raw/DNG files (which are TIFF internally) as TIFFs for examination without any processing intervention that would obscure the defects.

[The Gent.]

I had the same thing and sent the camera to Leica for a service and they fixed it. Something to do with the mapping.

[2Ms]

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I had the same thing and sent the camera to Leica for a service and they fixed it. Something to do with the mapping.

 

May I ask how much it cost?

[Dougg]

May I ask how much it cost?

In my case it was $0 charge by Leica about a year and a half after purchase, handled smoothly by my dealer, PopFlash, fine service. I understand that Leica was then (and perhaps still) regarding this as a camera defect to be addressed outside of the warranty.

 

However, I took that "opportunity" to have Leica install the upgraded shutter and framelines, so they did get some of my money!