Black Dots? - Try This . . .
/forum/topic/715521/0

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kevin2i
Registered: Apr 11, 2006
Total Posts: 156
Country: United States

I posted this on 'the other' site, but curious if this works for other 5dII owners who have the dreaded BDS (black dot syndrome), which could develop into IBS for the new owner . . .

Just picked up my 5dII, and sure enough, I see black dots with default settings.

At iso 400 and iso 6400, with a 50/1.8 and 85/1.2L II. I took a few dozen shots, and they are easily duplicated.

I then turned the settings to "Disable" for highlight tone priority, lighting optimizer and noise reduction.

No black dots.

I have only had the camera for an hour, but hopefully this solves the problem. Any other 5dII owners - please give it a try.

200%
Default settings top iso 6400/400
optimizer/noise reduction disabled iso 6400/400
dng>CS3



This image is copyrighted by the owner




jcbenner
Registered: Apr 27, 2005
Total Posts: 668
Country: United States

Very interesting. Thanks.



akclimber
Registered: Aug 01, 2002
Total Posts: 2465
Country: United States

Great find!

Cheers!



sirimiri
Registered: Dec 10, 2007
Total Posts: 2431
Country: United States

One would assume, then, it's not the sensor, but the camera's OS or in-body firmware that causes this "feature" to appear?



sboerup
Registered: Oct 13, 2005
Total Posts: 8535
Country: United States

Good find. All things that will only effect JPGs and NOT RAW (unless you are processing in DPP it might with RAW).



Gil_W
Registered: Sep 30, 2004
Total Posts: 1899
Country: United States

I have not had the BDS and tried to duplicate it for several hours yesterday. I also posted an image showing NO BDS over on the other side where it is pandemonium over this issue. Others also have not been able to duplicate it.

Strange you mention Highlight Tone Priority because I DO NOT use it due to it having a known history (Canon even states this) of increasing noise at high ISO (saw it in my 40D also) and turned it off before I ever took my first shot with the 5D mkII I only shoot RAW and some sRAW.

Maybe you found the answer!!!!



jerrykur
Registered: Feb 15, 2005
Total Posts: 3658
Country: United States

Great work! I sure hope this is the root cause of the problem.



Ariel Bravy
Registered: Dec 28, 2004
Total Posts: 7349
Country: United States

Bravo Kevin! Recognizing that it's a software issue, perhaps this can be fixed via a firmware update.



Caleb Williams
Registered: Dec 05, 2006
Total Posts: 2218
Country: United States

Great work. Hopefully Canon can fix this ASAP with a FW update.



CanAm
Registered: Apr 07, 2008
Total Posts: 110
Country: United States

I don't understand why anyone thought it was NOT a software issue to begin with.

Great find, Kevin. Irrelevant to me, but good to see that a bunch now have a workaround until Canon rolls out the firmware hotfix.



pietzcker
Registered: Oct 18, 2004
Total Posts: 14
Country: Germany

This is really interesting. I was under the impression that this phenomenon occured with RAW files just the same (I remember seeing a display of raw sensor data in some other thread on photography-on-the-net). And sboerup wrote that the mentioned options (highlight priority, noise reduction and lighting optimizer) only affect JPEGs, not RAW. Now I'm really confused.

I'm still waiting for my 5DII (pre-ordered it from Amazon, and they don't seem to have received enough units the first time around). I'm NOT cancelling my order since I expect this problem to be solvable. The positive buzz clearly supersedes the black dot phenomenon for me



Emile Gregoire
Registered: Sep 09, 2004
Total Posts: 2361
Country: Belgium

sboerup wrote:
Good find. All things that will only effect JPGs and NOT RAW (unless you are processing in DPP it might with RAW).


...except for highlight tone priority.



pietzcker
Registered: Oct 18, 2004
Total Posts: 14
Country: Germany

Emile Gregoire wrote:
...except for highlight tone priority.


Do you have any source for this? Like a listing of which settings will affect the RAW image, and which settings only affect in-camera JPEG generation? That would help a lot in reducing speculation in the forums...Thanks!



Will Patterson
Registered: Nov 06, 2006
Total Posts: 3884
Country: United States

sirimiri wrote:
One would assume, then, it's not the sensor, but the camera's OS or in-body firmware that causes this "feature" to appear?



And as I mentioned a few times now, will probably be fixed in the next firmware release.



CMOS
Registered: Jun 14, 2005
Total Posts: 850
Country: United States

Yesterday (with the 5D2) I was shooting indoors in some very uneven lighting and I was severaly blowing highlights at high ISO all over the place. But I had no black dots anywhere.

The common factor with the OP: I had disabled highlight tone priority.
However, lighting optimizer and noise reduction were set for their default settings, which I believe is "enabled" for lighting optimizer and "standard" (or something like that) for noise reduction.

So it might be all in the highlight tone priority, which would make sense and that feature is supposed to help with dynamic range while the vignette fixer and noise are not as closely related.



Rick Krejci
Registered: Sep 11, 2006
Total Posts: 369
Country: United States

This has since been debunked...it has nothing to do with HTP, NR or any other post-processing setting (other than HTP's effect on ISO).

It happens in the raw file before any processing, so it is introduced before any image processing.

I've posted examples here showing the effect (and had all the features the OP indicated disabled or turned off)
http://forums.dpreview.com/forums/read.asp?forum=1032&message=30277522

It only seems to happen when there are extreme contrast changes and for small light sources (a few pixels). Larger areas don't seem to induce the black dots. And if surrounding areas are brighter, it's reduced or eliminated. Lower ISO's are not immune, but the odds of the correct setup are reduced. I've clearly seen it at ISO200, but I had to try.

If I didn't do astrophotography, I would worry about this at all, since it's a minor effect visible only at 100% or so.

Rick



osucowboy8
Registered: Mar 01, 2004
Total Posts: 660
Country: United States

Tag!!! Thanks for posting this. My 5DII is on the UPS truck and I intend to try this out tonight.
J



RDKirk
Registered: Apr 11, 2004
Total Posts: 8477
Country: United States

Do you have any source for this? Like a listing of which settings will affect the RAW image, and which settings only affect in-camera JPEG generation? That would help a lot in reducing speculation in the forums...Thanks!

This is suggested by an absence to the contrary. For the Auto Lighting Optimizer, the manual states: "For RAW images, the contents of the setting in the camera can be applied when processed with Digital Photo Professional (bundled software)."

It does not include that statement for Highlight Tone Priority.



Emile Gregoire
Registered: Sep 09, 2004
Total Posts: 2361
Country: Belgium

pietzcker wrote:
Emile Gregoire wrote:
...except for highlight tone priority.


Do you have any source for this? Like a listing of which settings will affect the RAW image, and which settings only affect in-camera JPEG generation? That would help a lot in reducing speculation in the forums...Thanks!


RDKirk already answered part of the question. Highlight Tone Priority happens to be a feature on my 1D3, so I simply know it works on RAW as well. It's simply underexposing by a stop and then bumping it up later during post-processing and it does this for both RAW and JPEG. Besides reading it works this way, I actually noticed it back when Capture One 3.7 hadn't been updated with HTP processing: it simply showed the images underexposed by... exactly 1 stop.



dnenciu
Registered: Jul 25, 2005
Total Posts: 621
Country: Canada

RDKirk wrote:
Do you have any source for this? Like a listing of which settings will affect the RAW image, and which settings only affect in-camera JPEG generation? That would help a lot in reducing speculation in the forums...Thanks!

This is suggested by an absence to the contrary. For the Auto Lighting Optimizer, the manual states: "For RAW images, the contents of the setting in the camera can be applied when processed with Digital Photo Professional (bundled software)."

It does not include that statement for Highlight Tone Priority.


HTP is the only setting that affects RAW. It underexposes the photo and increases the iso in order to preserve highlights.

Personally I do not understand why I would want to leave it on. It is only useful in photos that have blown highlights. and even those have to be extreme cases not to be able to recover them from the raw file. For all other times all it does it's boost the iso and underexpose introducing noise.

If you shoot only jpeg I understand, for the rest I would personally dial in the underexposure myself if I need it.



sboerup
Registered: Oct 13, 2005
Total Posts: 8535
Country: United States

As far as I am aware, Highlight Tone Priority is a JPG only setting. You can use it on your RAW files, but only if working within DPP. It's not magic people . . . HTP just uses a special tone curve to process the image, which effectively brings down your highlights a bit.

To test this, take a pic with any camera with HTP ON (in RAW), then take the same pic, no settings changed, with HTP OFF (in RAW) and compare both of them in ACR or LR. There is no difference as far as I'm aware.

So, unless anyone else has info that I haven't read yet, this is what I have learned.



bka20d
Registered: Sep 17, 2004
Total Posts: 1753
Country: United States

sboerup wrote:
As far as I am aware, Highlight Tone Priority is a JPG only setting. You can use it on your RAW files, but only if working within DPP. It's not magic people . . . HTP just uses a special tone curve to process the image, which effectively brings down your highlights a bit.

To test this, take a pic with any camera with HTP ON (in RAW), then take the same pic, no settings changed, with HTP OFF (in RAW) and compare both of them in ACR or LR. There is no difference as far as I'm aware.

So, unless anyone else has info that I haven't read yet, this is what I have learned.

i don't use it, but if you take your raw shot at iso 100, and then turn highlight tone priority on and take the same shot, the iso defaults automatically to iso 200...i would expect a higher shutter speed to assist in recording better highlight detail but at the expense possibly of some shadow detail....it seems to me that this differential should be reflected in the raw files whether they are opened in dpp or acr.....
as for the optimizer, the raw files can be adjusted in dpp, which suggest that the optimizer is a tag on the raw file which is read in dpp, but not necessarily in thrid party apps....



Emile Gregoire
Registered: Sep 09, 2004
Total Posts: 2361
Country: Belgium

Spencer, please reread what I said about opening the 1D3 files in an earlier version of Capture One. All my RAW files were 1 stop underexposed when using HTP. Since an update to the program to cope with this, C1 reads the HTP tag and automatically adds a stop. Just like ACR, LR, DPP, all the rest. Just because you don't notice, doesn't mean it doesn't happen.



ayip
Registered: Oct 22, 2005
Total Posts: 121
Country: United States

I tried some tests last night with all those settings turned off, and I'm still seeing black dots:
5D Mark II Black Dots



akclimber
Registered: Aug 01, 2002
Total Posts: 2465
Country: United States

ayip wrote:
I tried some tests last night with all those settings turned off, and I'm still seeing black dots:
5D Mark II Black Dots



Ugh. Very disappointing. I'm still waiting for my 5D2 to show up. The only reason I was an early adopter was because I was sure Canon wouldn't, couldn't possibly allow the release of yet another piece of flawed gear. Guess I was wrong. I won't be cancelling my order but I may return it if it produces the black dots and canon doesn't quickly addres the issue.

Cheers!



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