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5d mark II strange black dots?


ivan_gunduli_

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I have seen few of high ISO night shots with new 5D mark II from various sources and it seams to me that there

some very strange picture quality issues.

 

On night cityscape shots strange black dots appear around light sources. That thing would not bother me if the

problem is specific for high ISO values but you can see those black dots even at 100 ISO.

 

Can anyone confirm that issue. I think no matter what camera settings are, those kind of things should not happen.

 

I have provided link bellow where you can see

 

<url=http://glubsch.wordpress.com/>http://glubsch.wordpress.com/</url> (scroll down on night city shots)

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Seems very obvious to me, totally bizarre, and totally unacceptable. I wouldn't expect that it would show up so much more prominently at higher ISOs if it was a RAW converter issue, but I guess it's possible. If the same thing showed up in camera JPEGs, I'd say it's got to be a hardware problem.
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If it's in the camera, hopefully it's a firmware problem, not a hardware problem... Since the black dots appear right after the bright areas I would guess that there is a bug in some compression/decompression code somewhere. Did you have highlight recovery turned on? It's conceivable that there is an interaction.
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"Ronald Moravec

Maybe my eyes are failing, but I checked 100 & 1600 and do not see black dots. I do hope the fog had rolled in

before you took those."

 

Scroll down and look at night city shots.

 

Blog is not mine I stumbled on it. I just noticed that error and have same informations as you guys.Thing is that

I have seen few other shoots from other people (some of them on dpreview but I can't find them now) in similar

shot conditions and they all show that kind of errors.

 

I think it's some kind of in camera processing glitch but I'm not sure.

Since I'm planing to by 5d mark II myself I was wandering has anyone else encountered same problems and maybe

somebody knows why is that happening?

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At the risk of telling the Emperor he has no clothes on but where I come from they are called windows.......

 

Now we all knew this stupidity would start but listen guys, you are pixel peeping other peoples stuff at web resolutions, for goodness sake at least talk about your own pictures and any issues you might have with them.

 

This is just crazy. Take care, Scott.

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Normally I find that your opinions tend to gel with mine, but I'm afraid I disagree with you here.<br><Br>

 

The small images on that page link to full sized versions - <a

href="http://glubsch.files.wordpress.com/2008/11/_mg_0166.jpg"><b>here</b></a>, for instance - and the black dots

along

the edges of the buildings are clearly <i>unacceptable...</i>

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Funny how it only appears in a series of what seem to be city street lighting, mainly in the area of the provided crop. I wonder if

there might be something physical about the lights that is being represented by that black pixel. I live in SF, have no real desire

to go to work on time tomorrow, so will take the train downtown and check out the lights. I've scanned the photo at almost all

ISO's and only found this in the presented crop, another area with similar lighting, and a few isolated places after that. I am

sure everyone will be eagerly anticipating my report.

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Daniel- If you're talking about the crop above, you've got to take another look at the full pictures. It's all

over the place, especially where the lights are running up the building edges. It's hard *not* to see it

everywhere. And like I said earlier, it's also in the bridge photos, both ISO's (worse as ISO goes higher, but

still there at 100). Look to the side of any of the lights- it's there.

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"Upon further examination", you're right. I see it in the bridge lights. Seems to be mainly on the right hand side. So, as a 30D

portrait shooter, how much difference does this make? I wouldn't crop this far on shots this big without expecting something.

BTW, I really did think it could have been something physically about the lights. The Embarcadero in SF has some pretty artsy

architechture.

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"I don't see the problem in these night shots, which were JPEG encoded in the camera:

 

(link)

 

That leads me to suspect a problem in the RAW converter used in this example."

 

They are all over that picture: on the left bottom corner you can see stripes of black pixels. They are harder to notice because of in camera noise reduction but they are still visible. On the lights in the restaurant (right from the entrance)

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I didn't realize my photos would create such an interest. I signed up with Photo.net just to participate in this thread :-)

 

Let me answer some of the questions here, even if they were already answered in my blog or somewhere else. The shots were taken in RAW format only. These spots show up even at ISO 100, though not as black holes. I've turned off all in-camera post-processing operations (though I don't think they apply on RAW shots anyway). My picture settings were set to "neutral" and Highlight Recovery was turned off. I Used ACR 5.2 in PhotoShop CS4 (trial version). I can see the same black spots using DPP (version 3.5.1.0) that came along with the camera.

 

Scott, I'm happy for others to pixel peep in my photos. That's why I posted them, albeit for demonstrating the camera's great noise performance, not to talk about the black dots :-)

 

I took a shot of the Golden Gate Bridge last Saturday during the golden hour. The photos were taken at ISO 100. Unfortunately the black holes are quite visible in that photo. It's early in the morning right now, but I hope to add another blog entry with an example later today. Since I set the camera to save RAW+JPG, I will be able to see if the spots occur there too.

 

I wish I knew who to contact at Canon to make them aware of this camera behavior. Not just an email that will get absorbed in the bowls of the corporate monster, but really to someone who's a subject expert. So if you know the right person, post it here. If you are hesitant to leave the contact info here in this thread, leave me a comment on my blog at glubsch.wordpress.com. I won't publish it (I have to approve all comments before they become public).

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Stephan,

Sorry I didn't realize it was your photos, do you have the long exposure NR set to ON or auto by any chance (this is different from high ISO NR)? There might be a bug with dark frame subtraction...set this option to OFF and try taking a 30+ sec exposure with the lens cap on and see what happens.

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