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M8 green streaky lines at ISO 640 - Diagnosis?


wstotler

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These have just started appearing in shots. . . . Ran back through my galleries just to be sure.

 

(1) Searched around on the forum (keywords: streaks, lines, banding, etc.) and couldn't find any exact match for this issue. If I missed a thread on this, sorry in advance.

 

(2) I've provided the original (underexposed) shots and the (overly brightened) post-processed shots so you can see the streaks I'm mentioning.

 

(3) It's not a dead pixel problem because the streaking is different in every shot, really.

 

(4) I've never seen this issue at ISO 640 (or higher). And I've shot plenty of underexposed shots that never looked like this. :D

 

Is this sensor failure or another known issue? It's the fact that I haven't seen these before and they've just started appearing that has me a bit worried.

 

And, yes, the photos are awful. Just posting them here so people can have a look and comment on the STREAKS. :D

 

Thanks!

Will

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There have been two major instances of green streaks in the M8's history. The original "bug" from the introduction in Nov. 2006, which involved green steaks and blobs from bright light sources within the frame (or mirror images of same). And the green streaks that can still emerge if a bright light source falls precisely on the edge of the sensor/frame.

 

Obviously bright light sources aren't involved in your shots - but it is interesting that the streaks themselves look similar in color (dark green) and tone.

 

This may well be the sensor doing a death dance - but it might also be a flaw developing downstream in the image pipeline. A reading error where the signal flows off the sensor, or a glitch in the analog/digital conversion process.

 

The even spacing in the stripes of the first picture, and the fact that they only appear in the lower half of the frame, also make me think there is some kind of interference effect. Nikon and Canon cameras have had repetitive banding like this due to electrical interference from the AF motors cycling in some modes.

 

Regardless, I think this will require a trip to Leica (and probably all the way to Germany), for a scientific tracking of where the bug is, and likely to have some part of the electronics replaced.

 

There is a terrible devil's bargain in silicon semiconductor solid-state devices. They give us incredible power in increasingly small packages and at decreasing prices - but they operate at the level of subatomic particles and are subject to the whims of quantum physics.

 

Maybe we should just go back to cathode tubes and film.... =8^o

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I'd say you've got a sensor problem there, and not a typical "green streak" issue. I'd send it into Leica as soon as you can.

 

There is a small possibility of RF interference. You weren't perhaps shooting with a large microwave transmitter strapped to the camera? :)

 

I think this is a service call.

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Will,

 

How old is your M8?

 

Is it still on warranty?

 

Have you ever sent it in for this 'line' problem?

 

Have you ever had your M8 into a high voltage area, like a trafo station, - or high ampere area, like a aluminium plant?

 

Do you work on any top secret US weapons project involving high voltage lasers? (If so, send me the drawings of this device, and I will see what I can find out).

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Could be interference from, say, a mobile phone or Wireless LAN but the electronics are in a preety effective Faraday cage which improves the immunity to EMI.

 

Your shots are grossly underexposed and pushing them in RAW by the amount you did will simply exagerate any non-linerarities.

 

You may have a sensor/sensor board problem but I'd look critically at correctly exposed images first.

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Hi Will,

 

These don't look so good - hope it's not something that is going to become widespread. One question that I have, what was the condition of the battery? In theory it could be a voltage drop while the camera is writing the info to the SD card. Have you tried a different battery?

 

Andreas

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I agree with the others that you "MAY" have a sensor problem BUT the only time I have seen a green line running across a image, horizontally, is when there was a bright light at the edge of the sensor/image. Otherwise the green/blue/whatever color line caused by a sensor problem has always been in the vertical direction.

Saying that the images you posted look like crops of the full image, and yes they are grossly underexposed. Could be there is a bright point light, bright for the exposure these images were taken at, at the edge of the image.

 

Could we see the full images and then some that are exposed correctly.

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Thanks, everyone, for posting thoughts. I'm feeling like it's a trip to NJ but I'm loathe to ship it. :D

 

Here's a quick follow-up reproducing the problem and with some additional information.

 

(1) About 1 in 3 underexposed shots show this green streak condition. Sometimes, the green streak shots are in a row, other times not.

 

(2) Lens doesn't matter. Cron, older glass, coded, non-coded, no difference.

 

(3) Battery is fresh. Swapped batteries mid-testing to be sure of freshness.

 

(4) Problem does not appear in properly exposed shots. (And, in underexposed shots *in the past* that I've adjusted severely, the problem didn't appear.)

 

(5) Problem will appear at 160ISO, also. Last photo in set was shot at 160.

 

(6) Camera is a chrome M8 (Feb. '07, SN 310xxxx), firmware 2.004 installed (many OK shots on .004 before this developed), little over 34K shots.

 

(7) Spurious radiation in the room is not an issue, nor has the camera been exposed to radiation/high energy situations. Perhaps it's my kids' latent psychic powers manifesting.

 

New shots attached, replicating the issue. Note that *some* of the shots in this series (not posted) had no signs of streaking--even with identical shooting conditions, seconds apart. So, frequency is random, but can be reproduced. :)

 

If you look in the dark areas on the original shots I'm providing, you can see the streak even before I (overly) bump up the exposure/brightness.

 

I guess what I'm getting at is that gross underexposure used to mean just bad noise--not a streak, too.

 

It might be OK to say "just don't underexpose your shots" but sometimes underexposure/bumping in post is needed to grab shots in bad light (or with f/4 glass in marginal light).

 

I'll be contacting Leica today to see what, if anything, they can do.

 

Thanks,

Will

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I agree with the others that you "MAY" have a sensor problem BUT the only time I have seen a green line running across a image, horizontally, is when there was a bright light at the edge of the sensor/image. Otherwise the green/blue/whatever color line caused by a sensor problem has always been in the vertical direction.

Saying that the images you posted look like crops of the full image, and yes they are grossly underexposed. Could be there is a bright point light, bright for the exposure these images were taken at, at the edge of the image.

 

Could we see the full images and then some that are exposed correctly.

 

Shootist--they aren't crops. There was no point of bright light at the edge. :) I know what that problem is and I've seen it two or three times.

 

Correctly exposed images do not exhibit this issue--just those taken in low light. The streaks *do appear* in the original images (very darkly) but become very apparent when pushed in post.

 

My concern stems from the fact that in the past I've shot in low light, bumped up the exposure in post, and have gotten noise--but never streaks. This is a new problem (for me, at least.)

 

I chucked together a gallery for Leica Technical Service of underexposed images that have been bumped in post and you can have a look at that over here:

Streaking - Page 1

 

Note that some of the shots have been labeled "Expected Condition."

 

The "Expected Condition" shots demonstrate the expected appearance for when I would bump underexposed shots (since February 2007). Crappy with a lot of noise and some "lineyness", yes, but no streaks. Shots like this could be converted to B&W photos and pass for "OK."

 

Adan--based on your post's comment "Nikon and Canon cameras have had repetitive banding like this due to electrical interference from the AF motors cycling in some modes." I ran a series of tests (not shown), shooting in Discrete, Regular, and Continuous shooting modes. No difference in behavior. Streaking appeared in all three modes, shooting fast, slow, etc. Just trying it out. Thanks.

 

Thanks,

Will

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These have just started appearing in shots. . . . Ran back through my galleries just to be sure.

 

(1) Searched around on the forum (keywords: streaks, lines, banding, etc.) and couldn't find any exact match for this issue. If I missed a thread on this, sorry in advance.

 

(2) I've provided the original (underexposed) shots and the (overly brightened) post-processed shots so you can see the streaks I'm mentioning.

 

(3) It's not a dead pixel problem because the streaking is different in every shot, really.

 

(4) I've never seen this issue at ISO 640 (or higher). And I've shot plenty of underexposed shots that never looked like this. :D

 

Is this sensor failure or another known issue? It's the fact that I haven't seen these before and they've just started appearing that has me a bit worried.

 

And, yes, the photos are awful. Just posting them here so people can have a look and comment on the STREAKS. :D

 

Thanks!

Will

 

Hi Will,

send the original DNG photo to the Leica Service. They can tell you exactly what it is.

 

regards

philipp

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My M8 is now at Leica where they are telling me that they will be replacing the sensor. I am beginning to have doubts to the reliability of the camera after shooting some 500+ images at a wedding reception and seeing fluorescing pixels of red, blue,green flare spots and a faint vertical line stemming from a dead (white) pixel. I was shooting at ISO640 at f2-2.8 I've spent hours trying to correct for some 100+ occurances in more than a third of my images. I don't know when my M8 was produced but I just wish they just replace it in it's entirety.

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I know it feels like a camera quality problem but at least part of the responsibility must rest with Kodak. It would be interesting to know how many of the sensors go back to Kodak for analysis and whether they are doing anything to clean up their fabrication process.

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I had my sensor replaced too for a dead pixel-line issue recently. the new sensor produces much smoother noise at high iso, and also does not have the blooming characteristics of the old sensor which would produce maze artifacts around over exposed blooming edges.

 

I think not all sensors are created equal is the answer. there is sample variation. now we'll see how long this one lasts.

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I know it feels like a camera quality problem but at least part of the responsibility must rest with Kodak. It would be interesting to know how many of the sensors go back to Kodak for analysis and whether they are doing anything to clean up their fabrication process.

 

Come on, Mark. Leica has to turn to Kodak for relief on something like this but it's Leica's baby. The buck stops there. Fact is, it IS a camera problem and the camera label says, "Leica" inside a red dot.

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My M8 is now at Leica where they are telling me that they will be replacing the sensor.

I don't know when my M8 was produced but I just wish they just replace it in it's entirety.

 

Don't be so quick to ask for a replacement. I did for a black M8 that Leica couldn't fix the rangefinder on and the NEW replacement camera had a line in the sensor.

4+ weeks later, and 2 (TWO) trips to Leica NJ I finally had a black M8 that worked.

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I'm not understanding. You get really weird results when you try to post process underexposed images; isn't the solution to expose correctly?

 

Honestly - is this sort of response intentionally obtuse?

 

The OP has very clearly stated the specific and very precise conditions under which he gets these lines and banding, with exhaustive examples on his website to show the expected result together with the faulty response. He really couldn't be more careful in documenting the problem - which is obviously (and worryingly) a dying sensor. I'm genuinely hoping that something can be done about it - as someone who's getting impatient to get my hands on my M8 after it's (initial?) sojourn in Solms.

 

Then this type of post. For goodness sake.

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