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Old June 29th, 2009, 07:42 AM   #1
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Strange red dots in 5D mark II

Hi everybody.

I got my 5DmII 2 weeks ago.
After a few testing journeys I experienced some strange red dots like the ones in the folowing images when taking stills:

http://www.serraicostes.com/5dm2/5d_test2_big.jpg

100% crop

http://www.serraicostes.com/5dm2/5d_test2_100per100.jpg

They were shoot at 100ISO, f8,1/6 firmware 1.1.0.

I have owned a 20D for 4 years and this kind of phenomenon only apeared when making long exposures (4 or 5 minutes), but not so many as with the 5DmII.

The strangest thing is that before the sun rise I took the same picture several times and the red dots did not apeared. They only apeared when the sun began to iluminate the scene, they seem to be due to the reflex of the warm light. The red dots are allways at the same place in different image. I shoot some images in low light and high ISO and the red dots haven`t appeared again.

can anybody help me?
Is this phenomenon any kind of noise?
Should I send the camera to the tecnical service?
Is this usual in 5Dm2?

Thanks for your posts

Tomeu Santandreu
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Old June 29th, 2009, 08:15 AM   #2
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Can you do this shot with a 20D (or another slr) at the same time, same settings.

Could it just be the reflexion and partial sun shining through kelp illuminating it?

Have you noticed this in any other shots?

Do you have IR reduction filter? It is a good idea to use with long exposures (that is maybe why you saw this earlier with long exposure in the 20D), and greatly reduces overly red images.

I would bet the same shot with IR filter would be at least a little different.

Last edited by Olof Ekbergh; June 29th, 2009 at 08:33 AM. Reason: Added Note
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Old June 29th, 2009, 09:47 AM   #3
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There was a red dot bug in the first firmware release. Have you updated your firmware?
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Old June 29th, 2009, 01:39 PM   #4
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these look like typical clipped (out of gamut) saturated highlights w/sharpening artifacts that often appear along horizons (in sunset shots) on all the canon dslr's. Typically the fix for them has been to lower the in-camera sharpening, or if you are shooting raw (and hopefully you are) you can just do it in ACR or DPP. The color will probably remain the same, but they will lose the pixelated/posterized quality they have now...also...make sure your camera is set up using Adobe RGB not sRGB...

Barry
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Old June 29th, 2009, 03:21 PM   #5
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My mistake. The 1.0.7 firmware fixed black dots, not red ones.

http://www.unwir3d.com/887274/canon-...x-or-just-mask
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Old June 29th, 2009, 03:44 PM   #6
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I thought the shot looked perfectly fine... those "dots" are the sun's reflection off the brown kelp.
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Old June 30th, 2009, 01:31 AM   #7
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Hi everybody for your messages.

I think the red dots are due to the sun reflecting on the wet dark kelp, but that kind of reflection is not natural. May be due to the argument Barry posted. Do you have any example to compare Barry?

The shots were took in RAW and adobeRGB was set in DPP.

I will try to repeat the same shots with the 20D (I don't have IR reduction filter).

Thanks everybody.

I will keep you informed
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Old June 30th, 2009, 12:41 PM   #8
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Tomeu,

I agree that the color is there naturally...just a reflection of off the kelp...and sometimes kelp can almost have a metallic /oily sheen that could be the source of the entire effect...it does look like there are "maybe" some other artifacts as well...if you have them in raw...try lowering the sharpening in ACR or DPP and see what happens...

Barry
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Old July 2nd, 2009, 03:17 AM   #9
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Hi Tomeu,

The camera EXIF data indicates this image was taken 'CreateDate>2008-05-12' before the 1st firmware update. Have you got any more resent examples.

Also would like to see the original image, or crop before it goes through raw workflow. I have seen this effect before normally when an under exposed image is brought up .

Every Canon I have owned, Video or still the reds are also a little hot and edgy.
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Old July 3rd, 2009, 07:35 AM   #10
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Hi James!

The date was not adjusted when I took that shots. They were my first ones with the 5Dm2, so I just wanted to test the camera. At that moment I didn't mind the date of the camera, I just updated the firmware and go...
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Old July 8th, 2009, 03:55 AM   #11
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Hi everybody.



It was impossible to reproduce the effect again due to the wheater. I took some photos from home during the sunrise, the sun wasn't as low as in the other images.



Only a red point appeared. It was very close to a red leave of a tree, it appeared in the 2 shots I took at the same point in the image, not in the sensor. So, I think the red dots are only reflections.



Lets take photos and forget minimal issues!



Thanks.



Tomeu Santandreu
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