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12-08-2020, 06:37 AM   #1
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a stupidly failed Pixelshift image

A while ago I decided to test K-70's pixelshift by shooting some panorama cityscapes on my home's rooftop. Mounted the camera on the tripod, and I thought it would be good to go. However several months later when I started processing one of the pixelshift file with RawTherapee, I noticed that the image with virtually no moving subjects is covered by a huge motion-mask. I zoomed in and tried to examine it, I saw some movements between four sub-images caused by weird distortions, and it took me a long time to realized that it might be the infamous electronic shutter distortion that caused this movement. I haven't seen anybody reporting this, and it's pretty silly, so I think it would be good share it here, so that people can exam their own images. The attached GIF demonstrates the distortion between the 2nd and the 3rd sub-images.

By the way, English isn't my native language, so I apologize for any unclearness in advance.


Last edited by syyrmb; 09-03-2021 at 10:54 PM.
12-08-2020, 06:55 AM - 1 Like   #2
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Mmmh... was it quite hot and the subject far away?
I'm thinking heat distortion more than electronic shutter distortion, which I don't think should be an issue with static subjects.
12-08-2020, 07:05 AM - 2 Likes   #3
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Yea - atmosphere seems like a likely culprit here. I have not had this issue (yet?) when shooting pixel shift with my KP.
12-08-2020, 07:28 AM - 1 Like   #4
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Yes, definitely thermals. You did not lose anything, the image wasn't sufficiently sharp to start with. Pixel shift can't fix that.

12-08-2020, 07:34 AM   #5
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Also keep in mind that when shooting photos with a long zoom that any movement (even caused by wind) can affect the final outcome in pixel shift.
12-08-2020, 07:59 AM   #6
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Very strange...

I don't think it's due to atmospherics. The EXIF shows focal length as 50mm, so the building can't have been far away.

It looks very much like one of the images has lens distortion correction applied, and the other doesn't I'm wondering if there might be a bug in the version of RawTherapee the OP is using.

@syyrmb - would you be willing to share a copy of the file for us to investigate? If so, I could give you access to my Google Drive to host it...

Also, have you tried to process the photo in PDCU?

Last edited by BigMackCam; 12-08-2020 at 08:08 AM.
12-08-2020, 08:12 AM   #7
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QuoteOriginally posted by BigMackCam Quote
I don't think it's due to atmospherics. The EXIF shows focal length as 50mm, so the building can't have been far away.
You could be right - although I also think we're looking at a zoomed in crop of the image so still not clear how far away the building was.

12-08-2020, 08:17 AM   #8
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QuoteOriginally posted by eric3929 Quote
You could be right - although I also think we're looking at a zoomed in crop of the image so still not clear how far away the building was.
Hopefully the OP will clarify.

I've never seen atmospherics create such a clear and consistent distortion of lines whilst also retaining sharp detail. For me, it has always presented as either a general softening and / or rippling effect... but I'm open-minded to any possibility. It's a weird one, that's for sure
12-08-2020, 09:30 AM   #9
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QuoteOriginally posted by BigMackCam Quote
Very strange...

I don't think it's due to atmospherics. The EXIF shows focal length as 50mm, so the building can't have been far away.

It looks very much like one of the images has lens distortion correction applied, and the other doesn't I'm wondering if there might be a bug in the version of RawTherapee the OP is using.

@syyrmb - would you be willing to share a copy of the file for us to investigate? If so, I could give you access to my Google Drive to host it...

Also, have you tried to process the photo in PDCU?
Looks too random to me to be lens correction, unless that lens has the most weird m(o)ustache distortion... it's like there are vertical bands that get alternatively compressed and stretched... moreover there should be next to no correction near the center of the image (and it's all gree apart from those area with uniform detail/color).
I'm still voting for heat ripples.
12-08-2020, 09:43 AM   #10
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I've done some pixel shift images but none outside have ever turned out that great. Granted I'm using a K-3ii so it was still new with that camera but the only times it has ever produced a noticeably better image when I've shot indoors. I think a lot of it is because of camera shake from the environment as most of the time I don't have one of my ultra heavy ultra stable tripods with me. I did try a pixel shift moon shot once but a front was coming in so the few attempts there were just a hot mess. I want to give that a go again as I have seen some pixel shift moon shots from a K-3ii but need the weather to cooperate.

If it were shake from mirror slap I would expect the movement to be up and down in the image not left to right so I would think the problem may be from a not stable enough tripod in some wind.
12-08-2020, 11:58 AM   #11
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I want to know how to make that happen.
12-08-2020, 05:12 PM - 1 Like   #12
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QuoteOriginally posted by LensBeginner Quote
Mmmh... was it quite hot and the subject far away?
I'm thinking heat distortion more than electronic shutter distortion, which I don't think should be an issue with static subjects.
QuoteOriginally posted by eric3929 Quote
Yea - atmosphere seems like a likely culprit here. I have not had this issue (yet?) when shooting pixel shift with my KP.
QuoteOriginally posted by Breakfastographer Quote
Yes, definitely thermals. You did not lose anything, the image wasn't sufficiently sharp to start with. Pixel shift can't fix that.

I think it's not thermal, because it's one of the panorama shots, so if it's really a thermal issue, then all my images that were shot that day will suffer from that, but no, this was the only one.

Also the part that I cropped was an out-of-focus area, so it might not be very sharp, but the weird distortion is across the frame.

---------- Post added 12-08-20 at 05:41 PM ----------

QuoteOriginally posted by BigMackCam Quote
Very strange...

I don't think it's due to atmospherics. The EXIF shows focal length as 50mm, so the building can't have been far away.

It looks very much like one of the images has lens distortion correction applied, and the other doesn't I'm wondering if there might be a bug in the version of RawTherapee the OP is using.

@syyrmb - would you be willing to share a copy of the file for us to investigate? If so, I could give you access to my Google Drive to host it...

Also, have you tried to process the photo in PDCU?
I‘d say the building is at least 500 meters away from me.


I just tried to disable lens correction in RT, no effect, still the same, and I believe the distortion is in the image for my experiment with DCU below.

I uploaded my file to there: IMGP1415.zip - File.re temporary file sharing

(please only use it for studying purposes)


After hearing your suggestion, I tried DCU and disabled motion correction, image shows motion artifact and blurs, which shows that the distortion is inherited in the image.
12-08-2020, 06:06 PM   #13
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QuoteOriginally posted by syyrmb Quote
I think it's not thermal, because it's one of the panorama shots, so if it's really a thermal issue, then all my images that were shot that day will suffer from that, but no, this was the only one.
The problem with your hypothesis is that rolling shutter (if that is what you were suggesting) doesn't produce artefacts while sat on a tripod shooting a stationary scene. So I would favour most other explanations over that one.

QuoteOriginally posted by syyrmb Quote
Also the part that I cropped was an out-of-focus area, so it might not be very sharp, but the weird distortion is across the frame.
Okay, if that's so, it might be sharp in the center. I'm afraid I don't have time to confirm this from your files, but hopefully someone else will look at them and come back with some ideas.

QuoteOriginally posted by syyrmb Quote
I‘d say the building is at least 500 meters away from me.
A very plausible scenario for what's been suggested as an explanation.
12-08-2020, 07:00 PM   #14
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QuoteOriginally posted by Breakfastographer Quote
The problem with your hypothesis is that rolling shutter (if that is what you were suggesting) doesn't produce artefacts while sat on a tripod shooting a stationary scene. So I would favour most other explanations over that one.


Okay, if that's so, it might be sharp in the center. I'm afraid I don't have time to confirm this from your files, but hopefully someone else will look at them and come back with some ideas.


A very plausible scenario for what's been suggested as an explanation.
I don‘t think February in a seaside city located at 36*°N is hot enough to produce enough heat to distort the air.


I'm starting to wonder if it was my tripod shaking a little bit that caused this, since rolling shutter's jello effect only appears when the subject is moving. If that's the case, I'll blame the wind & my tripod setup.
12-09-2020, 01:35 AM   #15
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Yeah, given the additional information you provided wind becomes the most likely suspect, probably.
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