Lens correction in PTGUI or before?

[dher...@gmail.com]

Hi,

I often read that lens correction (except CAs) should NOT be done before feeding photos into stitching software.

However, my experience from a set of tests recently is that I get better stitching results in PTGui if I let Lightroom correct the lens distortion beforehand.

If I feed uncorrected images into PTGui, sometimes in the upper edges of rooms (where typically there are not many feature for finding control points, just the edge itself) I get stitching errors. I am pretty sure I have the non-parallax point set precisely. 

This is for focal length of 16-35mm on fullframe and spherical panoramas. 

What way is recommended and why?

Thanks

Daniel

[PTGui Support]

Hi Daniel,

I've seen that enabling lens correction in lightroom can cause subtle
irreparable distortion. But if it improves things for you then you
should obviously enable it.

If you think PTGui's distortion correction can be improved, please make
a set of images available for download. Preferably a set taken outside
(to reduce the effect of parallax) and with lots of details for placing
control points.

Kind regards,

Joost Nieuwenhuijse
www.ptgui.com

> A7R07135 Pano Kopie.jpg
>
>
> --
> You received this message because you are subscribed to the Google
> Groups "PTGui Support" group.
> To unsubscribe from this group and stop receiving emails from it, send
> an email to ptgui+un...@googlegroups.com
> <mailto:ptgui+un...@googlegroups.com>.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/ptgui/a542ba48-e1b4-445b-af54-3307a8a08435n%40googlegroups.com
> <https://groups.google.com/d/msgid/ptgui/a542ba48-e1b4-445b-af54-3307a8a08435n%40googlegroups.com?utm_medium=email&utm_source=footer>.

[dher...@gmail.com]

Hi Joost,

I'm a little in doubt that my first impression was correct. What I observe now is that it sometimes takes minutes(!) for the panorama in the panorama editor to change back and forth to get and lose such stitching errors. So I am not sure what edit really caused them to vanish and what edits may cause them to reappear, as there is no real time correlation between edits and results showing up in the panorama editor. 

It would help a lot, if there was an indicator that the panorama editor does still not show the final edit result. 

This is what just happened:

- Panorama editor showed a stitching error (even after lend correction in Lightroom)

- I added two control points in the areas of question

- I ran the Optimizer

- Panorama editor showed panorama without stitching errors shortly after (yay!)

- I wanted to create the panorama some time later, but shortly before hitting "Create" button, panorama editor changed and a corner of another adjacent image suddenly entered the area (upper edge of a room between ceiling and a wall) and introduced a new stitching error. 

- Then I lowered the Blending > Find Optimum seams > Precision value

- Shortly after, the corner of that "new" image retraced from that area again and no stitching error anymore.

- But now I'm not sure if any time later, that may change again...

Mac Pro with 3,5GHz 6-core Xeon E5, 64GB RAM and 1TB SSD. 

2x AMD Fire Pro D700 6GB, GPU OpenCL support, as well as GPU for Panorama Editor and Detail Viewer enabled in PTGui and GPU device set to "Automatic".  (is there a better configuration for this kind of system?)

(Even though that system is a few years old, I don't think that it should take THAT long for PTGui to do any calculations without an indicator. If calculations are expected to take long on a system that's newer than, say, 10 years, I think a progress indicator should be shown. :) Not a modal one maybe, but just a progress animation in a corner of the panorama editor or so, just to indicate to the user "attention, wait with further edits until the last edit results are shown!"...)

Daniel

[PTGui Support]

Hi Daniel,

There’s a spinner in the bottom left corner of the panorama editor. When it’s finished, the panorama editor shows the true seams.

-- 

Kind regards,

Joost Nieuwenhuijse

www.ptgui.com

On 5 Apr 2021, at 11:22, dher...@gmail.com <dher...@gmail.com> wrote:

Hi Joost,

To unsubscribe from this group and stop receiving emails from it, send an email to ptgui+un...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/ptgui/695bb3ba-2bf7-45ac-8a8d-9f0fbfcb7979n%40googlegroups.com.

[dher...@gmail.com]

Oh. *blush*. :D 
I haven't noticed it before.

Indeed this indicator solves my problem almost entirely. For the remaining issues, I need to understand PTGui better and collect experience. 

Thanks

Daniel