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Auto horizon levelling

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26 comments

  • Thomas Kyhn
    Top Commenter

    I agree. Auto levelling doesn't work very well, particularly not if the horizon is interrupted – as in a case like this:

    In my experience, auto keystone doesn't work very well either. It happens that the result is OK without further adjustments, but usually you only get a rough approximation, and often not even that as the auto keystone function is easily thrown off by shadows, electric cables, lamp posts, lines on the road, etc. 

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  • Fabrizio Giudici (stoppingdown)

    I see even worse stuff: completely unobstructed horizon line and very minimal photos, and still it fails.

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  • Thomas Kyhn
    Top Commenter

    That looks familiar.

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  • JoJu

    I just found one image, which was close to perfectly leveled, at 400% I could not detect any wrong angle - lucky shot. After auto leveling (-0.1°) the horizon line was clearly higher at the right side. Makes me ask with what the auto-leveling is working? I recall having problems with it since the beginning. You're right, Fabrizio, the keystone tool doesn't need manual corrections as often as (the imo more simpler) auto-leveling does. 

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  • Thomas Kyhn
    Top Commenter

    As both auto levelling and auto keystone almost always require additional adjustment, it would, in my opinion, be preferable if Capture One focused on making it easier to make manual adjustments. For levelling: an option to straighten a photo by placing a line along the horizon. For the keystone tool: adding a loupe, unlocking the adjustment points and saving the adjustment point positions when you close the application.

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  • JoJu

    "For levelling: an option to straighten a photo by placing a line along the horizon." Thomas Kyhn this is already possible. Also, as usually a bit of cropping is involved I can rotate the crop frame.

    I know, the keystone tool is something you're highly involved in it's improvements. I support your idea, but here's the thread for sort of sloppy done auto-horizon levelling. :D

    Edit: and your suggested loupe (I think, adding a CTRL or ⇧key would be helpful) should also be implemented for the straightening tool.

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  • Thomas Kyhn
    Top Commenter

    Oh, of course, you're right, that option's already there. The only inconvenient thing is that the icon, the plus with the circular arrow, obstructs the view of the horizon.

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  • JoJu

    Sorry, haven't refreshed my browser. Hence my suggestion to add the loupe also for the straightening tool. It would be more convenient than constantly jump from view all to 100% or more, just to get that correct.

    Of course, sometimes it's unnecessarily pedantic, other times, especially in architecture or product photography, it's a simple must, else no manufacturer of geared heads would have any business...

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  • Fabrizio Giudici (stoppingdown)

    Drawing a line to level in theory could be done with the "Straighten" tool, but I am unable to use it: every time I try it (also for vertical lines) I still need manual corrections (so in the end I always use "Rotate freehand". But in this case it could be my fault, who knows?

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  • JoJu

    The cursor of the "straighten tool" doesn't allow precise aiming or an enlarged view of the area it's aiming at in one go. I'm also only "good enough" using it. If I want to be really precise, I use a workflow of construction lines (don't know the C1 translation of "Hilfslinien") and either the crop tool or moving the angle slider.

    But why is the automatic process so faulty? Is C1 using a low res preview? But even if so, one of my example was perfectly leveled before the auto-levelling and bad afterwards.

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  • Fabrizio Giudici (stoppingdown)

    I use the same approach you described and yes, I can confirm that both of my examples above were perfectly leveled by hand before applying the tool.

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  • Walter Rowe
    Moderator
    Top Commenter

    Please include the version of Capture One you are using where auto-rotate is not leveling the horizon.

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  • Thomas Kyhn
    Top Commenter

    Has there been any change to the auto-levelling function?

    This is with the latest version of Capture One, 16.3.2.32.

    Before:

    After:

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  • Fabrizio Giudici (stoppingdown)

    In my case, every C1 version since when there is the auto align function up to 16.2.5.9. I've upgraded to 16.3 a few days ago (after posting this topic), but I've not tried the function with this latest version yet.

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  • Fabrizio Giudici (stoppingdown)

    I did a couple of tests. Something has changed because one of the test images that I posted a few days ago is now correctly aligned; but there are others that aren't, and they are pretty simple cases.

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  • Nevency

    @house of hazards I think your suggestion is very valuable and I hope Capture One will consider implementing it. Automating horizon levelling would be a huge time-saver for photographers, especially those who work frequently with seascapes and landscapes.

     
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  • SFA
    Top Commenter

    Thomas, 

    Your 2 examples above seem to have slightly different crops.  Or perhaps a tiny amount of rotation? Or maybe slightly different lens corrections?

    Is that actually the case? If so might that be a factor in the Auto-generated horizon levelling results?

     

     

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  • Thomas Kyhn
    Top Commenter

    SFA

    The only difference between the two versions is that auto-levelling has been applied in the second ("After").

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  • Marcin Mrzygłocki
    Top Commenter

    I think I noticed one thing: automatic rotation works best for me, when there are strictly vertical elements in the frame, like wall corners, columns, or windows.

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  • SFA
    Top Commenter

    Thomas,

    OK, so the adjustment is a slight rotation. That explains the differences.

    Is the vertical subject in the centre of the frame more vertical in the before or the after version?

    I ask because some images I have taken, with testing in mind, sometimes look "wrong" in some odd way after aligning to what is apparently a useful horizon line as is the case with seascapes.

    I'm wondering how much the vertical elements of an image are taken into account when trying to auto adjust horizon lines. 

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  • Thomas Kyhn
    Top Commenter

    SFA

    It may be slightly more vertical after the adjustment, but it doesn't seem right that a small cone-shaped object would be used for levelling when there's a horizon spanning the whole image.

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  • JoJu

    When we speak about "time saver" for a well done auto-levelling, I think most of us take C1's way to apply that individually to each image, one after another for granted and the only way.

    DxO uses a rather different approach: Every "AUTO" element, be it levelling, exposure, tone correction is applied individually to each selected image. And this happens on-the-fly! No need to copy adjustments from one image to the others.

    Whereas C1 applies the angle value of the first image the adjustments are copied from stubbornly to each image the adjustments are distributed to. Rather annoying, imo. If I want to give each image the same value I can do so with using th double arrow. But the real time-saver, again imo, is the ability to treat each image individually when it comes to auto-adjustments. Else it's always post-treatment. 

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  • Fabrizio Giudici (stoppingdown)

    I ask because some images I have taken, with testing in mind, sometimes look "wrong" in some odd way after aligning to what is apparently a useful horizon line as is the case with seascapes.

    I'm wondering how much the vertical elements of an image are taken into account when trying to auto adjust horizon lines. 

    Clever remark. While I don't think it happens in those cases of mine that I posted above (there are the sails of the sailboats, but they are so small), actually lots of seascapes can have slanted vertical lines: thinking of larger sailboats, poles near a pier, umbrellas on the beach, etc... One more reason for having a dedicated horizon leveling option, I'd say.

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  • Walter Rowe
    Moderator
    Top Commenter

    JoJu said:

    Whereas C1 applies the angle value of the first image the adjustments are copied from stubbornly to each image the adjustments are distributed to.

    Of course! I would be very disappointed if copy-apply didn't do exactly that.

    If you want to auto-level a batch of images, then select the batch of images and press the Auto button in the Rotate tool. That will do what you want - auto rotate each image separately.

    You also can include rotate in the set of Auto adjustments affected by the Auto button in the menu bar. If you select a batch of images and press it, Capture One does exactly the same as DxO.

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  • JoJu

    My bad. I did so, it just came out in each image a different horizon. I mean, different in deviation from the horizontal line.

    Thanks to your comment I tried the same with DxO (old version 5, currently they're on 7). Subject was a scaffolding around a historic building. In terms of autocorrect the horizon, DxO did pretty good, whereas C1 showed different angles, but none was "correct".

    Interestingly that changed in another series showing scaffolding and a corner shape of the old tower. Here C1 hit it in all four images: the corner was shown perfectly vertical - and the scaffolding looked out of place. Unfortunately the tower is not exactly vertical, it's thicker at the bottom and gets thinner. DxO oriented its auto-align on the many posts of the scaffolding and ignored the corner shape. See for yourself which result looks better to you. I find it difficult as both main elements have no clear horizon.

     

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  • Walter Rowe
    Moderator
    Top Commenter

    Perhaps the increased contrast of the scene allowed Capture One to better detect vertical and horizontal lines.

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