5d mark II strange black dots?

<p>and here's a screen shot with RGB reading<br /> </p>

<p>looks like new photo.net interface is buggier than what it was before! I can't attach the photo because is larger than 700 pixels! any ways, the reading for the black spot is (2,4,16) also this photo was taken in portrait orientation so the black spots are now on top</p>

<p>and here is a conversion with ACR.</p><div></div>

<p>Whilst at massive enlargements there is obviously an issue here, on a note of sanity, has anybody seen a picture at normal viewing magnifications where this is obvious and detracts from the image?<br>

Seems to me another storm in a tea cup so far. People seem happy with their camera and pictures until they are being told they aren't! Yes it would obviously be better if this didn't happen but come on, lets start seeing some pictures at normal viewing conditions where image quality is degraded by this, at the level being studied so far the black dots don't equate to much difference to individual grain particles when using film.<br>

As an academic pursuit to establish why this is happening then it has some merit, maybe, but so far, as an image quality issue there is nothing.<br>

Take care, Scott.</p>

<p>Scott- I would say that architectural photographers will have a really rough time of it. Very detail-oriented, lots of point sources of light. I would guarantee that some of the folks i have worked for in that industry would return the camera immediately if this were a hardware issue and not a firmware fix.</p>

<p>(of course, they're already shooting on the 1dsmkIII, but still. It wouldn't become a backup body.)</p>

<p>As someone who is looking to the 5dmkII to replace my hasselblad, I'm really disappointed. I don't need a perfect camera or ueber resolution, but I do need no obvious defects and the ability to print 20x24, and these dots would mean i was constantly worrying about missing something in the retouching process. It also is a bit of a confidence-buster, making one worry about 'what else will go wrong', though that seems a little silly. (once you have a 4x5 lens misfire a couple times, you're always worrying about it, and will probably end up replacing it, even if it works 98% of the time).</p>

<p>imho.  anyway, it has me really grumpy and very hesitantly postponing my purchase until next fiscal year.</p>

<p><span style="font-family: Tahoma; font-size: 14px;"> </span></p>

<p>Brad, I don't think there is too much to worry about on the retouching process. A little testing under photoshop shows that it's fairly easy to create an action which removes the black holes...</p>

<ol>

<li>Color select pure white with a 58 tolerance </li>

<li>Move selection right (or up) by 4 pixels </li>

<li>Remove light shades from selection </li>

<li>Dust removal filter </li>

</ol>

<p>So if mine has it, I'll live with it.</p>

<p>@ Scott</p>

<p>I would say the images from the original post are that bad.  The lit edges of the buildings in the center and left of center look terrible at what I would think is a normal viewing magnification.  http://glubsch.files.wordpress.com/2008/11/_mg_0167.jpg</p>

<p>i took the 5Dm2 and a 400 f/5.6 prime to the waterfront here in toronto to shoot the city's skyline to test this issue a bit further.   being -10 degrees celcius on the lake, it was a little chilly to say the least but did manage to knock off a few tests both JPG and RAW.  I've yet to examine the raw files in depth as I need to still install DPP for the 5dm2 or ACR update (on the list of things to do today) but from the JPG's I can determine that the problem starts surfacing at ISO400.  It's "slightly" evident at ISO100 - not there at all ISO50....<br /> this is a super close crop from ISO400... trivial maybe but still to me indicates an issue.<br /> <img src="http://farm4.static.flickr.com/3178/3086348331_83277cff79_o.jpg" alt="ISO 400 black splotches" width="278" height="185" /> <br /> For the full shot at different ISOs  go here:</p>

<p>http://www.flickr.com/gp/79642675@N00/U5x5vZ</p>

<p><br /> Interestingly, its evident on one ISO3200 shot but the following ISO3200 with high ISO noise redux set to ON it was not evident.   JPG's have been posted full res, untouched direct from the DCIM folder with links to download the full res shot.  The link above will take you to a private set on flickr - hover your mouse over the skyline shots which will identify what ISO they are.</p>

<p><br /> also this astro photog has reproduced it here:</p>

<p>

<p>and more seriously with this shot on a car:</p>

<p>

<p>[[The lit edges of the buildings in the center and left of center look terrible at what I would think is a normal viewing magnification.]]</p>

<p>Has anyone here actually printed one of these "problem" images?  I see lots of wailing and gnashing of teeth but has anyone actually, you know, <span style="text-decoration: underline;">used</span> these images in anything beyond 100% and 200% viewing on web pages.</p>

<p>Wonder when someone will email Canon to see what they say.</p>

<p>Bruce, the answer from Canon is <a href="http://forums.dpreview.com/forums/read.asp?forum=1032&message=30249392">here</a>.</p>

<p>Thanks Xavier, I hadn't seen their response.</p>

<p>What do you guys think? Are you satisfied it is a simple firmware isssue?</p>

<p>Guess we will see.</p>

<p>I don't have the 5D MkII yet so will be watching this issue closely.</p>

<p>Rob: I've printed some of the images posted, and on an A3 print the black dots are clearly visible. They would render certain images unusable, in my opinion.</p>

<p> </p>

<p>Brad,</p>

<p> You have to be kidding, a $2,500 prosumer 35mm body to replace a Hasselblad system where you are working to individual pixel level, you say your not concerned with uber resolution but that is what this thread is all about. I think your expectations for the 5D MkII were way too high. From a pros point of view, as Xavier points out, there is a very simple auto action you can use to eliminate it and that takes virtualy no time. It certainly wouldn't stop me buying one if it fitted my buisness plan.<br>

 Don't get me wrong, yes the camera needs a firmware update to eliminate this issue, but lets keep it in perspective, a few shots, in a few conditions, from a few cameras, render some pixels in need of an auto adjustment that is very easy to do.</p>

<p>  Mike and Micheal, run Xavier's action and tell me the picture is unusable. How many shots do you print that need no alterations or adjustments? So far I just don't see this as a big issue, slightly annoying, yes, but particularly when put in the context of a full blown, new, highly complicated electronic item launch, really not a big issue.</p>

<p>Take care, Scott.</p>

<p>Scott-</p>

<p>Sorry, I should be more specific.  I love the hasselblad, but there are several projects i'm working on that need things it just doesn't do (high ISO, more inconspicuous appearance, AF, AE, etc.). </p>

<p>Yes, I want high resolution (I guess printing 20x24 is high resolution) but I meant that I'm not pretending this camera is something it ain't- I know it doesn't _have_ ueber resolution- it isn't a leaf back, and any image won't be MF/LF quality, but I still have the 4x5 for that, while I'm selling the 'blad.  I don't have the camera, so I admit I haven't tried the fixes that are mentioned, and it sounds like they may fix this issue fairly painlessly for those of us with a workflow that involves a decent amount of post-production already, all of which is good.</p>

<p>But I'm less disappointed by this specific flaw, and more worried that this is a fairly blatant mistake, and that I should really wait until they've had a bit of time to work through the v1.0 bugs.  I would like to be more confident in the camera while I'm working with it, but this all makes me a bit nervous, and I'd rather put off the projects rather than begin with technology that I'm nervous about. </p>

<p>(Of course, at this point, perhaps i'm just sour graping, since availability is so limited.  grin.)</p>

<p>Hi Scott. Yes, the action helps, but it didn't remove all the dots on some of the images I ran it on. On one of my test images, for example, it failed to remove about 50% of the dots. Not sure why; perhaps because some of the lights with adjacent dots were not entirely blown out (i.e. white), but retained some yellow.<br>

Of course for most images the dreaded dots won't be a problem. However, for some images they will.<br>

I hope that a firmware update will be possible, and that a recall won't be required, as it was with the 24 -105 f4 L lens flare issue.<br>

I really must stop being an early adopter!<br>

 </p>

<p>Scott, Is there a reason why you are so insistant that I feel the same way you do about this?  If I bought a TV and found out it didn't have a power button, I wouldn't keep it just because I can still turn it on ond off with the remote.  If you are ok taking the extra\alternate steps to work around the problem, I guess you're just more accepting than I might be...but I hope it's OK if I don't share your opinion.  I don't own this camera but was thinking about upgrading to it and this kind of discussion is important to me as I'm not so willing to work around things like this if I can avoid it.  I'll wait to see if it can be fixed with a firmware upgrade or if it's going to take a recall to resolve.</p>

<p>Thanks Chris for taking the time to post these images, I may not be correct but it seems that the artifacts are more pronounced when the fine lights are in focus (e.x. your astro shot) when the lights blurry (e.x. your cityscape shots, I belive this was mirror vibration since you were using 400mm) the artifacts are much less visible.</p>

<p> </p>

<p>Mike, the photoshop action was made very quickly, it needs to be polished and tested on more than one image... My intent was just to show that it should be fairly easy to create one.</p>

<p>Thanks for making it for us, Xavier. I'm not an expert in these things by any means, so if you are prepared to share your expertise with the rest of us, I for one would be very grateful. I don't do many night shots, but I'd like to know that I can if I want to!<br>

Of course, the availability of fixes in Photoshop does not absolve Canon of the duty to fix this issue....</p>

<p>The artifact is commonly referred to as the 'Black Sun' effect in CMOS sensors. <a href="http://www.appliedcolorscience.com/black_sun.htm">A description of the mechanism is shown in this article</a>. It is doubful that this issue can be solved with a firmware since it typically require the addition of a circuit to provide a reference level that is not affected by the bright signals and a black sun detection circuit in the readout path.</p>

<p>Interesting Berg, if there is leakage of charge from an overexposed pixel to the adjacent area I wonder why the black pixels appear only to the right of the bright pixels.</p>

<p>Thanks Berg, very interesting...<br>

Mike, OK its sunday morning, I've tried to do better starting with the 6400 ISO image from <a href="http://glubsch.wordpress.com">http://glubsch.wordpress.com</a>.</p>

<ol>

<li>Color Select pure white with a 58 tolerance</li>

<li>Move selection right by 4 pixels</li>

<li>Color Select Dark Shadows</li>

<li>Dust Removal Filter with a radius of 13 pixels and a threshold of 19 levels</li>

</ol>

<p>It's better, but there is still some room for improvement though. I promise that once I have this camera, I'll put my optimized action on a "5D Mark II Tips and Tricks" page on <a href="http://www.fovegraphy.com/Technique.php">my website</a>.</p>

<p>I don't get it. If Canon puts out a black-dot model, why didn't them label it as such on the package? .....  </p>

<p>:-)</p>

<p><br />Seriously, it seem to me as a very minor issue.</p>

<p><br />Happy shooting,<br />Yakim.</p>

</p>

<p>Yakim,<br>

This is the super AF black-dot version ;)</p>