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M8 effects


bernardofeio

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Hello to all

 

Is this normal?

 

It’s an over exposed photo but it happens quite often when I have a strong light source.

 

The camera already went several times to repair (other things) and it always returned like this...

 

always the vertical line in the midle of the CCD

 

thnks

regards from portugal

bernardo feio

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No, it's not.

 

The green banding is normal (Leica said it will be corrected with firmware) but the vertical line in the middle means sensor fault.

 

You need to send your camera to Solms. If you have just bought it, ask your dealer to be replaced.

 

If you can live with this for a few weeks, send you camera to Solms in a few weeks (end of October). They will probably replace also the CCD board card for the new type.

 

Good luck

.

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Can you post some other example ? The line seems exactly at the middle, and is notorious that M8 CCD is composed by two "halves" that transfer data separately... this problem has arisen other times in this forum... you are a newbie, I see, and you can try to search through the "SEARCH" menu (try keywords like "vertical" "line" "vertical band" "CCD"... sorry but I cannot post directly a link... I had to search for it like you... I didn't suffer this problem in my M8, so don't remember which was the trick, but anyway was CCD-related and remember of having red of fixing at the factory.

Were your pics RAW or JPG shot ? Seem to remember also it's related to this, and to ASA setting...

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I think this is "normal" for the current cameras. There is no central vertical band that extends for the complete height of the picture. It only appears at the end of the green stripe. The green stripe is caused by stray light getting to black level reference cells at the edge of the imager. There are two columns of reference cells one at the left and the other at the right hand side. There's one for each half of the image, that's why the green stripe ends abruptly in the center giving the impression of a vertical line. In the Bayer matrix there are more green pixels than blue or red which is why the stripe is always green.

 

I don't think your camera has a problem other than the green stripe, which all M8s have.

 

Bob.

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I don't think your camera has a problem other than the green stripe, which all M8s have.

 

Bob.

 

Bob, maybe I'm lucky but I don't have the green band in any of my two cameras. I tried to reproduce this effect many, many, times. It simply doesn't happens... Well, maybe one day it comes out when I don't expect it (hope not!)

.

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Bob, maybe I'm lucky but I don't have the green band in any of my two cameras. I tried to reproduce this effect many, many, times. It simply doesn't happens... Well, maybe one day it comes out when I don't expect it (hope not!)

.

I think you're lucky :D I've used two M8s and both have shown this effect - once, in many thousands of shots. Under normal picture taking conditions it's most unlikely to occur. The light source has to hit the edge of the frame in exactly the right place to get the stripe to appear. In both examples I had it was caused by a bright horizontal flourescent tube, half in and half out of the frame. I think that's the key to getting the effect - it needs an extended light source which overlaps the edge of the frame. I've tried to reproduce this with a point light source without success, the positioning must be very critical.

 

Bob.

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I think you're lucky :D I've used two M8s and both have shown this effect - once, in many thousands of shots. Under normal picture taking conditions it's most unlikely to occur. The bright light source has to hit the edge of the frame in exactly the right place to get the stripe to appear. In both examples I had it was caused by a bright horizontal flourescent tube, half in and half out of the frame. I think that's the key to getting the effect - it needs a very bright extended light source which overlaps the edge of the frame. I've tried to reproduce this with a point light source without success, the positioning must be very critical.

 

Bob.

 

Yes, I know. It was a thread here few weeks ago showing how to reproduce this effect. I tried with my first body at the time. Using a flourescent tube, low comsummation bulbs, normal bulbs... I think I shoted at least 50 pictures following the instructions on the thread. Nothing! I tried two days ago with th new body (you know I'm rather upset with this CCD board upgrade, don't you? :o ) and no green banding.

 

Yes, I think I must be happy... I'm lucky at least with this issue ;)

.

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same thing, another example

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Guest guy_mancuso

Unfortunetly this is normal as Bob mentions but very hard to induce also. You have to hit the light just exactly right for it to happen. 5 M8's and i still never got it . What happens is the outside the visable sensor area it is surrounded by black and light gets on the very side of it and that stray light causes the issue. it only happens when the light is on the very edge and also at a very precise certain angle. There still working on the fix for it . Now the sensor is split in two so the reason it ends in the middle is normal.

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As Guy says, this problem occurs when black reference pixels are affected by bright incident light; the firmware assumes the pixels are in the dark and tries to adjust the data in these rows on that basis.

 

The solution I proposed to Stefan Daniel earlier this year was to recognise the situation by looking at the variance in the reference pixel values and then do another closed shutter exposure to obtain correct reference pixel values which would replace the ones in doubt, or more probably, the complete set.

 

That may or may not be how they tackle the problem but as Guy says, most of the time it only occurs if you go looking for it.

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Extreme lighting condition. I am not too concerned as my expectation for M8 (for extreme situations) is low while I am enjoying the supreme image qty of the M8.

 

My expectations shot up considerably :)

 

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Hello

 

Thanks to all

 

I bought the camera in January or February and it already went 3 times to solms to repair other problems.

 

This problem occurs in DNG and JPG and it’s not 1 in a million shot. It’s a “regular” problem.

 

I don’t think that this should be normal….

 

it's not a banding situation but instead a situation were the left and right part of the CCD react in different ways..

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Hello

 

Thanks to all

 

I bought the camera in January or February and it already went 3 times to solms to repair other problems.

 

This problem occurs in DNG and JPG and it’s not 1 in a million shot. It’s a “regular” problem.

 

I don’t think that this should be normal….

 

it's not a banding situation but instead a situation were the left and right part of the CCD react in different ways..

 

That may be an misunderstanding. The CCD is read out in two halves and goes through two seperate amplifiers. On some digital backs (and a few faulty M8's this leads to the problem where there is ALWAYS a division in the middle of the image, the socalled centrefold problem. On the MF backs it seems to be incurable, on the M8 it is a correctable fault. In this case it explains why the green band stops in the middle,and in that sense it is anormale aspect. i agree the green band should not happen often (in fact should not happen at all) and if it is a regu;ar occurence on your camera it must be repaired. In fact, if the camera has already been repaired several times under garantee, you are entitled, imo, to demand a replacement or at least a speedy repair.

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I think this is "normal" for the current cameras. There is no central vertical band that extends for the complete height of the picture. It only appears at the end of the green stripe. The green stripe is caused by stray light getting to black level reference cells at the edge of the imager. There are two columns of reference cells one at the left and the other at the right hand side. There's one for each half of the image, that's why the green stripe ends abruptly in the center giving the impression of a vertical line. In the Bayer matrix there are more green pixels than blue or red which is why the stripe is always green.

 

I don't think your camera has a problem other than the green stripe, which all M8s have.

 

Bob.

 

Green Stripe Normal? Not in my experience. I have had none of this what so ever. Looks like a sensor problem to me. I have not experienced anything like this at all.

 

Gene

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Yes, I know. It was a thread here few weeks ago showing how to reproduce this effect. I tried with my first body at the time. Using a flourescent tube, low comsummation bulbs, normal bulbs... I think I shoted at least 50 pictures following the instructions on the thread. Nothing! I tried two days ago with th new body (you know I'm rather upset with this CCD board upgrade, don't you? :o ) and no green banding.

 

Yes, I think I must be happy... I'm lucky at least with this issue ;)

.

 

Manuel,

You really need to get over the parts change. It is simply a change due to parts unavailability. This happens all the time in the electronics industry. Manufacturers of parts drop parts availability or change specs almost daily. I'm surprised Leica even mentioned it at all. It means nothing to the rest of us M8 owners, as it has no effect on operation at all.

Gene

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Gene, the green stripes are uncommon but do happen. Leica acknowledge this.

 

Go to this page...

 

Leica Camera AG - Photography - M8

 

...select 'KNOW-HOW' and then the FAQ at the bottom of the pop-up. Then read paragraph 5.5.

 

To quote...

 

"5.5 Bright sources of light near the image edges occasionally lead to a green stripe

reaching all the way to the centre of the image.

 

Leica is aware of this effect and its cause and is working on a firmware solution. This calls for

extensive programming and testing, so we cannot say exactly when the firmware will be ready. "

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