Cyan coloured artefacts on HDR photos - iPhone X

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Cyan coloured artefacts on HDR photos - iPhone X

Yesterday I noticed that the new photos I have taken with my iPone are showing a circular spot, cyan coloured. The spots are not in fixed place, on each photo in a different location. And they are only visible in the HDR version of the photo. The normal version of the HDR-Normal pair is fine, so it does not look like a problem with the lens.

Here are a few examples:

Is this a known problem?

Restarting the Camera.app and the iPhone did not fix it.

iPhone X, iOS 11.3.1, 256GB, space gray

Posted on May 14, 2018 2:21 AM

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Answer 1

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ProustGiulio

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208,518 points

May 16, 2018 1:52 AM in response to léonie

Léonie, I got it.

I didn't noticed this behaviour before, I don't use HDR mode on my iP7 that much.

Sun+moving water+backlit... (but don't ask me a tech explanation, 'cause I'm not able to give you an appropriate answer)... but your iPX is not guilty 😉.

Have a nice day.

Giulio

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Answer 2

léonie Author

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May 14, 2018 6:34 AM in response to léonie

So far, I have seen this problem only on HDR photos of a water surface with waves and bright, glittering reflections of the sun light. Come to think about it, it may be a HDR artifact caused by a saturation distortion. But I'd still like to know, if it is a problem of my iPhone X or to be expected when shooting HDR with the iPhone.

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Answer 3

ProustGiulio

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208,518 points

May 14, 2018 10:10 AM in response to léonie

Hello Léonie.

Does it happen only on HDR mode?

I can't replicate that "crazy big cyan pixel" because the sun is on strike today. But tomorrow I will take some backlit photos with my iP7, using HDR, and I'll let you know the results.

Not sure, but I think you hit the problem saying that it could be an artifact due to a saturation distorsion.

See you tomorrow, have a nice evening.

Giulio

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Answer 4

léonie Author

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May 14, 2018 10:09 AM in response to ProustGiulio

Does it happen only on HDR mode?

Yes, that is the weird thing. My iPhones are set to keep the normal photo and I can compare the normal version to the HDR version. Only the HDR versions are showing the cyan colored dots. The normal versions have been fine.

At first I thought it might have been a blinking buoy, and the HDR version captured the blinking, but the normal version does not show any traces of a buoy, and then the color should have been green and not cyan.

Thank you for offering to test this, Giulio!

I never saw similar with the HDR on my iPhone 5s.

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Answer 5

ProustGiulio

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208,518 points

May 15, 2018 8:31 AM in response to léonie

Even today the sun is not shining 😠.

I took a few pictures this morning (during a little clearing) but I wasn't able to reproduce your issue. Unfortunately in my town there are no canals or rivers with "rough" water, and I can only point my iP7's camera staying on the edge of a park's small pond, with quiet water). But a "full" sun is mandatory ! (to get a real backlit).

I'll keep you informed as soon as I can get good conditions for my tests.

Keep well, Léonie.

Giulio

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Answer 6

léonie Author

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May 16, 2018 2:20 AM in response to ProustGiulio

Wow, Giulio. Thank you very much.

I think you are right, when you suspect the glittering reflections on the water. The quickly moving specular reflections may be causing colourful ghosts, that the ghost removal algorithm cannot recognize.

I am keeping HDR set to "Automatic", and the iPhone should only take the HDR photos, if it is useful in the situation and there is no motion, that could cause ghosts.

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