Morning,

Is there a way to prevent straight lines becoming curved when stitching panoramas together?


Let's say I've got a 21 photo (is that a 180?) with a number of buildings in the foreground. After stitching in lightroom these become curved, especially if they are parallel to the camera, rather than at 90deg away from it.


Is this down to how I shot the photo in the first place, or can I resolve it during post processing?

Thanks

Some variation is possible with different projections but long straight lines close to the bottom bottom of the frame will always be an issue.
The longer the panorama, the more the issue.
Being aware of this helps you to avoid such compositions.
Look for grass/water etc at the bottom of the frame rather than straight lines.

Thanks. I'll bear that in mind in future. I am still experimenting with panoramas so I'm not always sure what works best

Hello there. We apologize for the inconvenience. Do you have a sample picture showing the problem?

Sure:

This is a pretty low res, scaled down version but hopefully you get the picture (pardon the pun!)

In the individual photos the perspective is correct on the buildings but they appear in more than one shot and at different angles so I guess when it comes to stitching them Lightroom isn't getting it quite right

Have you tried Microsoft "ICE" Image Composite Editor?

https://www.microsoft.com/en-us/ ... e-composite-editor/

Thanks, just given that a go but the result is the same. Having said that I might not be using it correctly so I'll have a bit more of a play around with it.

djmokoia77 Posted at 2018-7-18 06:33
Thanks, just given that a go but the result is the same. Having said that I might not be using it correctly so I'll have a bit more of a play around with it.

ICE is a good program but it won't eliminate the issue you are asking about.

djmokoia77 Posted at 2018-7-18 04:06
Sure: [view_image]

This is a pretty low res, scaled down version but hopefully you get the picture (pardon the pun!)

Nice image!
It doesn't matter which software you use. Imagine that a 180° panorama is a hemisphere.
And you are 'undbending' that hemisphere to become a 2D image.
That 'unbending' comes with distortion.

Good panorama softwares are PTGui or Autopano Pro.
But no software can overcome physics ;-)

https://www.ptgui.com

http://www.kolor.com/autopano

If you put that pano into an interactive app that views it as a 360° pano that you can pan and tilt around those curved lines would become straight again.
If you have any diagonally straight line place on a sphere regardless of the angle then straighten out that sphere you will end up with a curved line.
For example if you draw a straight line diagonally on a ball then cut that ball open and lay it out flat your straight line will now be a curved line.
Only way you will keep straight lines is if the original straight line is vertical from bottom to top from the perspective of the camera.

www.kuula.co  One of the interactive software tools.  

Takes a bit of work to get the little planet to the correct output resolution, but end results are nice.

Paul C