What to do with curved horizon

Processing
3

The wavy horizon is generally caused by several things:

  • Control points on clouds - never put CPs on clouds.
  • Incorrect verticals.
  • Bad lens distortion correction.

Bad lens distortion correction often has other signs which I don’t see in your pano, so the first two are the culprits. You should fix this in Hugin, not afterwards.

3 Likes
4

This really is the keypoint (and no control points on clouds, as Morgan wrote). If the horizon is distorted due to the lens, put three horizontal CPs in each frame: On the left, center, and right. This usually helps a lot. And remember to check the CPs on the +2 frame (e.g. 0 and 2, 1 and 3, …). Sometimes it’s faster to set the CPs manually than running CPFind and then deleting most of them, as you don’t need many.

3 Likes
5

Adding some automation to the above suggestions :slight_smile:

For straight lines, make sure you’re using Stereographic Projection - this will produce better lines straight out of a box

Then, there’s the ‘Straighten’ button in the Hugin’s ‘Move/Drag’ tab - Hugin move drag tab - PanoTools.org Wiki
using which may level the horizon, but not always
(in my experiemce, just using the Stereographic projection eliminates most of the problems so I need rarely use the Straighten)
For further finetuning the horizon, as well as foreground, background, rotation, leveling uneven series etc. I recommend using the abovementioned Move/Drag controls.
With all the above automated tools you can manipulate the entire panorama without having to add CPs manually.

Nice place, where is it?

p.s. I absolutely agree with Morgan, make sure you’re using ‘no CPs on clouds’ stitching.

6

Actually, the horizon is curved, IRL. :slight_smile:
https://dizzib.github.io/earth/curve-calc/?d0=48.28032000002595&h0=3.0480370641306997&unit=metric

7

Wrong dimension.

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That’s assuming the earth is a sphere.

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Wasn’t it a pizza???!!!

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I hope I find some time during holidays to experiment with hugin. Till today I found a place where I can move the whole pano with mouse and I can make pic look, hmmm… let’s say… almost good.
But it’s not what please me (if I can say that in this context ;))
The pano has ~47 or 48 pics and it took really lot of time to make 3-6 CP on each pair :slight_smile:
Balos - the place I really recommend to visit https://www.google.pl/maps/place/Balos+Beach/@35.5831025,23.5842373,16.25z/data=!4m5!3m4!1s0x149c5809c68e7ac7:0xe2cb9e4402502711!8m2!3d35.5792671!4d23.5887205
I’ll try your stereographic projection and let you know :slight_smile:
Thank you :slight_smile:

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yeah :slight_smile: hahahaha :slight_smile: but not in that way like on my pano :stuck_out_tongue:

12

Yeah, there are also people assuming the light in fridge is off when the door is closed…

2 Likes
13

If you want to post the files somewhere, I’m sure several of us will try and stitch it and report back.

14

The horizon should of course be curved, though I understand that you may want it to appear flat.

2000×1000 147 KB

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Sounds like a good idea, I’ll put files on my owncloud machine and share them here, but tomorrow, cause it’s night here and I have to get my kids go to sleep now :slight_smile:

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Oh, please do not go into politics here :stuck_out_tongue: :wink:

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Jeżeli chcesz - mozemy pogadac po Polsku :slight_smile: )
Jestem Polakiem z Ukrainy :blush: )

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So, if someone want to try with original files, there is a Balos file containing all jpgs.
It would be super, if you could give some suggestions based on that pictures :slight_smile:

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19

A nie byłoby to nie fair względem reszty towarzystwa? :slight_smile:

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I will certainly take a stab at it!

21

@volen some remarks in no particular order:

  • Use a pano-head. Adjust your pano-head’s least-parallax-point. In this pano it is not well adjusted and leads to problems.
  • Your overlap is far too high. Aim for 20% or so. Too much overlap causes bad stitching, it puts unnecessary load on your CPU, takes up unnecessary amounts of space on your memory card, hard drive and backup drives, it causes the whole process to take longer and require more RAM.
  • Your archive contains 49 images at 140MB. I cut this down to 8 images at 23MB. https://i.imgur.com/t1namQ2.png
  • Always set your camera to manual mode when shooting panoramas. These shots were taken in aperture-priority mode. In some cases programs can compensate for differences in exposure, but in this case, with a single row, where the center of the pano is darker than the edges, the software looks at the image on the left and sets its average exposure to fit well with the others, but the image on the left is different than the ones in the center - it is land + sky, while the ones in the center are sea + sky, so the result is that the land looks consistent throughough the panorama but you can see that the sky is not https://i.imgur.com/tEKm7v8.png
  • Shoot raw.
  • Sometimes you should correct the lens distortion before stitching. The stitching software may be able to correct lens distortion, and it could do that based either on a database of lens distortion correction parameters such as lensfun, or it could do it based on control points. In your case doing it based on control points leads to bad results because due to the nature of the scene there are only small areas where you can place them. You can’t put them on water or on the clouds as those change between frames. You can put them on the ground closest to the camera but that means that the optimizations will be calculated based on that area of the frame at the cost of the areas without any CPs, and in this panorama its actually the areas without any CPs where misalignment will be most noticeable - the horizon. https://i.imgur.com/GC9HZLI.jpg leads to https://i.imgur.com/ZcW6m6f.png
  • The things you put control points on are the things which will align the best. In this case you want the horizon to align. You can’t tell whether the shrubs are misaligned, but you can straight away see when the horizon is wonky. You may be tempted to put CPs on the most distant clouds. In this example, actually putting the CPs on the clouds https://i.imgur.com/xvDW4gc.jpg makes the lens distortion model of those two frames match and everything looks fine https://i.imgur.com/34ERfPh.png The rock at the bottom of the frame paid the price, but you don’t notice that as easily as you do a badly stitched horizon. However, even though the horizon touches perfectly between frames, the overall pano is wonky because the CPs were on moving objects.
  • In this pano I would put the CPs on the most distant non-moving parts of each frame https://i.imgur.com/fv6mr6p.jpg
  • Closing remarks: adjust your equipment before shooting to avoid such situations. Taking 3 more minutes to double-check and plan while shooting can easily save you 2 hours after shooting. Try to visualize the parts of the scene where stitching errors will be most visible and the parts which will be most usable for placing CPs and plan your shot accordingly.

Best I could get:

4980×1080 1.17 MB

5 Likes
22

Well, that’s a whole tutorial :slight_smile: at first lemme thank you for your time and effort :slight_smile:
Special head is on my shopping list, so soon it will be no problem, here I was trying to make some pics with the equipment, which I had with me

1008×1048 434 KB
. hahahaha :smiley:

[quote=“Morgan_Hardwood, post:21, topic:2893”]
You can put them on the ground closest to the camera but that means that the optimizations will be calculated based on that area of the frame at the cost of the areas without any CPs, and in this panorama its actually the areas without any CPs where misalignment will be most noticeable - the horizon.
[/quote] - I tried to put CP manually on the islands and the ground (4-6 Cp per frame), but this also failed and horizon goes down on the right side…
On your pano the horizon looks like straight line, as I was expecting to be, the way I was doing this leads to some kind of steps
Your answer is very informative, thank you again :slight_smile: