Align to Grid introduces Roll?

[Mike Cowlishaw]

Hi Joost,

For non-spherical panoramas I typically use a hundred of more images and therefore must use "Project -> Align to Grid" to avoid problems with large areas of sky with just bits of trees, etc.  This works extremely well, but I see some added roll in the aligned (and then stitched) panorama.  It's only a few degrees but is very noticeable.

The images I've used to show this (in subdirectory 'work') and the resulting uncropped panoramas and the .pts files are in:
   https://speleotrove.com/misc/MFC-20250617.zip

workA-pan.jpg is the result of simple processing with the wizard (load images, align images, create panorama).  The result is as expected .. the top of the curtain (bailey) wall is horizontal in the image, and the uncropped curve at the top is centred.

workB-pan.jpg was created using the same steps, except that before align images I went to "Project -> Align to Grid"  then set the rows and columns to 3 x 7 ( Roll angle was ticked as Do not change).  The result has a roll of about 2.5° and the uncropped top curve is no longer centred.

It's entirely posible that I changed some other setting in PTGui in the past that interacts with this.   Any idea what it might be, or how I can stop this happening?

Many thanks!  -- Mike

[John Houghton]

Mike,  The panorama needs to be levelled.  You can use vertical line control points on the hopefully vertical edges of the building.  That does seem to work well.  Or, you can rely on the fact that the roll parameters of all of the images are the same (but not exactly 0).  To do this, go to the Advanced page of the Optimizer tab.  Check pitch and roll of image 0, and check the Link roll box.  The optimizer will then optimize the roll parameters as a group of identical settings.  That will level the panorama with respect to the original vertical axis of rotation of the panorama head.  If the tripod was not precisely levelled, then the panorama will not be precisely level.  Or you might just link the roll and pitch parameters for a single row to get that level (with only that row selected in the Use control points of list), and then align the rest of the images to that row.  I'd go with the vertical line control points here.

John

[Mike Cowlishaw]

Hi John, thanks for the suggestions!  But the first stitch comes out just fine (i.e., level).  It's only when I apply 'Align to Grid' that the 2.5° roll appears.  I really don't want to apply manual corrections if they are not necessary.

(In any case, according to ExifTool, the source images don't seem to have any roll/tilt/pan information anyway -- see the .txt file in the work subdirectory.)

Background information: the tripod was very likely not level, but the camera is on top of a DJI RS4 Mini which seems to stabilise and level extremely accurately -- the camera is level as shown by its own level display and also when I check with a (large) external bubble level. 

Mike

[John Houghton]

On Saturday, July 26, 2025 at 5:22:23 PM UTC+1 Mike Cowlishaw wrote:

Hi John, thanks for the suggestions!  But the first stitch comes out just fine (i.e., level). 

Mike,  I felt that your first stitch didn't look quite level, which is why I tried levelling with vertical line control points.  This then did look level to me, and also gave the nice straight top and bottom as to be expected in a cylindrical projection selected here.  

John

[PTGui Support]

Hi Mike,

Align to Grid does not introduce any roll by itself, but you're running
the optimizer afterwards (I assume). This will need to adjust the image
parameters, including roll, to get a good alignment.

Take a look at the 'anchor image' setting in the Optimizer tab. For this
image the roll will not be adjusted. By default it's the first (top
left) image. In order to keep this image at roll=0 and still get a good
alignment, PTGui needs to adjust the roll of the order images by a few
degrees.

If you instead make the middle image (11) the anchor image before
running the optimizer, that one will stick at roll=0 and the panorama
will appear leveled. The outer images will still have nonzero roll but
that's really needed for good alignment.

Also note that Align Images does some extra magic, if you really want
the center image to stick at roll=0, don't use it. Instead, set anchor
image to 11, do Control Points - Generate Control Points for All Images,
followed by Optimize.

Kind regards,

Joost Nieuwenhuijse
www.ptgui.com

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[Mike Cowlishaw]

OK, thanks, both -- I'll experiment some more.

John -- it's possible that the first stitch is slightly off-level,  but recall that the castle is quite old and the verticals are not quite vertical, etc.,  But the second stitch is definitely off-level, by about 2.5°.

Joost -- no I'm not using the optimizer -- I tried it a couple of years ago but it didn't seem to have any affect so I haven't used it since.   Is 'align to grid' running it automatically, perhaps?

Mike

[PTGui Support]

No, Align to Grid just positions the images exactly in a grid. It
doesn't change the roll, unless you tell it to do so. You can verify
this by looking at the Image Parameters tab.

Aligning to Grid is generally not sufficient, even a deviation of a tiny
fraction of a degree will give stitching errors.

If you are running Align Images, you are in fact running the optimizer
under the hood.

Kind regards,

Joost Nieuwenhuijse
www.ptgui.com

On 7/27/25 13:16, Mike Cowlishaw wrote:
> OK, thanks, both -- I'll experiment some more.
>
> John -- it's possible that the first stitch is slightly off-level,  but
> recall that the castle is quite old and the verticals are not quite

> vertical, /etc/.,  But the second stitch is definitely off-level, by

> about 2.5°.
>
> Joost -- no I'm not using the optimizer -- I tried it a couple of years
> ago but it didn't seem to have any affect so I haven't used it since.
>  Is 'align to grid' running it automatically, perhaps?
>
> Mike
>

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[Manuel Dahmann (kubische-panoramen-de)]

Thanks - there must be a bug in PTGui 11 leading to projects without timestamp export. This was my default for 4 years.
EXIF timestamp is not mentioned in the PTGUI documentation, so I thought this was normal behaviour.
A newly created #11 project does export the timestamp. I'm still trying to figure out how to get older projects to output the timestamp.

[John Houghton]

On Sunday, July 27, 2025 at 12:17:09 PM UTC+1 Mike Cowlishaw wrote:

John -- it's possible that the first stitch is slightly off-level,  but recall that the castle is quite old and the verticals are not quite vertical, etc.,  But the second stitch is definitely off-level, by about 2.5°.

Yes, I was aware that the verticals might not be reliable in this relic,  but I thought that identifying several vertical features would give an averaging effect and so it proved to be the case.  The levelling performed by linking roll parameters produced a very similar result.  Note that when the panorama is level, the natural horizon will normally run across the centre point of the Panorama Editor window.  In both of your project files, the centre point is positioned half way up the main building, which is clearly not where the horizon actually was, as there is clear sky in the background.  The (hidden) horizon proved to be lower down at approximately the bottom of the surrounding wall.

As Joost said, the Optimizer is being run as part of the Align Images function.  If you switch into Advanced mode and display the Project Settings tab, you can see what operations can be optionally performed.  This makes it possible for an experienced user to exert a great deal of control over what actually happens.

John

[Manuel Dahmann (kubische-panoramen-de)]

Thanks.
Just for the records (my findings, because it is not documented):
PTGui 11 writes out the timestamp of the first image to jpg and tif, but not to psd and psb
PTGui 13 writes out the timestamp of the first image to jpg, tif, psd, psb, dng, but not to jpg 2000

[Mike Cowlishaw]

John, thanks.  Yes, you are exactly right -- the camera is level with [just below] the bottom of the curtain wall.   For a 'straight-on' view I'd need a tripod about 20m tall (or a much bigger drone than I have, since I'm using 350-400m lenses).   I'll have to think about that :-).

As I understand it, therefore, you are essentially applying 'keystone correction' during the stitch, which is nice.

[Separately, I took a few panoramas this morning, this time with a two-axis spirit level in the hotshoe so I could watch the levelling while the panorama was being taken.  The gimbal really did a good job -- the camera was level to better than 0.2° for every shot that I watched (about 1/3 of over 200) even though the wind was gusty enough that I could see the tripod swaying a little.] 


I wasn't aware that Align Images ran the optimizer -- that certainly explains why, when I tried it, the optimizer seemed to have no effect!

So I think what you are suggesting is a way to have 'Align to Grid' applied without running the optimiser .. but Joost's comment also suggests to not use Align Images.   But both his and your suggestions seem to have multiple steps, certainly more that the current 'Align Images' then 'Create (stitch) Panorama'. 

I'm trying to really simplify stitching, because for me it's a manual multi-step and slow operation that is a big chunk of my time for the many panoramas I make.  It takes more time that the photography.   Perhaps there's a way to automate the steps that you or Joost describe?   Ideally I'd like to write a Rexx script to effect them, but I recognise that is probably not an option :-).

Mike

[Mike Cowlishaw]

OK, thanks.  I wasn't aware that Align Images ran the optimiser (see my reply to John).

[Mike Cowlishaw]

Hi Joost, I just spent a couple of hours on this.   Setting the Anchor Image seems to have no effect, but I wonder if I am setting it in the 'wrong place' as there is no apply button?

Here is my current checklist, as used in latest try (on a new panorama from today):

1. Otherwise (large panorama):
   • Menu → Project → Align to Grid
   • Set Shooting configuration: e.g., Order: By row (top→bottom), Direction: Unidirectional (left→right always), Start at: Top Left)
   • Enter Grid dimensions (e.g., 5 rows× 14 columns)
   • Set overlap Spacing percentages (e.g., 30% in both H and V)
   • Orientation → Roll angle [tick] Do not change
   • Click “Apply”.  (Can now close that dialog.)
   • Left navigation → Optimizer
   • Set Anchor Image to middle image (e.g., 74 of 147)
   • Left navigation → Control Points
   • Menu → Control Points → Generate Control Points for all overlapping images, and wait until done
   • Left navigation → Optimizer
   • Click “Run Optimizer” and wait until done
   • Menu → Tools → Panorama Editor (to see result)
   • Left navigation → Create panorama
     → Adjust target filename to (e.g.) PanA-pan.jpg
   • Click “Create panorama” button to stitch the panorama
     → View → use default, to view

I must be doing something wrong.

(However, if somehow setting the Anchor Image to the middle image is the answer, why is the default image #1 and not the middle image?)

Mike

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[John Houghton]

On Monday, July 28, 2025 at 3:45:32 PM UTC+1 Mike Cowlishaw wrote:

I must be doing something wrong.

(However, if somehow setting the Anchor Image to the middle image is the answer, why is the default image #1 and not the middle image?)

Mike, You can select any image to be the anchor image.  It's entirely up to you, but don't choose a bland, featureless image (like blue sky) as there will not be any control points linking that image to any of the others.  The anchor image won't change its position or orientation in the optimization.  All the other images will move to align with themselves and the anchor, so the anchor image determines the final position and orientation of the entire panorama on the 360x180 spherical stitching surface.  You might choose the middle image of the bottom row, if that was shot with a precisely level camera pointing straight ahead.  You could then manually set yaw, pitch and roll parameters all to 0 on the Image Parameters tab for that image .

Then, after running the optimizer for the first time, run Delete worst points from the Control Points menu.  Check the Control points table.  There might still be some points with high control point distances remaining.  This can be the case with points on foliage blowing about in the wind or other moving features.  You might manually delete the worst of these (and rerun the optimizer, of course).  Investigate and correct/delete any bad points still left.  With your sample sets of images, I quickly got the average control point distance down to 1 with a maximum of 5, which is very good.

After all of this, your anchor image should still be at yaw=pitch=roll=0.  The panorama will not necessarily be level, depending on how level the camera was when the anchor image was shot.

John

[PTGui Support]

Hi Mike,

Anchor Image is used in the Run Optimizer phase. If you check the image
parameters, you should see that the anchor image does not get changed.

The exception is if you add horizontal or vertical control points and
use 'level in second pass': then even the anchor image will change.

Kind regards,

Joost Nieuwenhuijse
www.ptgui.com

On 7/28/25 16:45, Mike Cowlishaw wrote:
> Hi Joost, I just spent a couple of hours on this.   Setting the Anchor
> Image seems to have no effect, but I wonder if I am setting it in the
> 'wrong place' as there is no apply button?
>
> Here is my current checklist, as used in latest try (on a new panorama
> from today):
>

> 1. Otherwise (large panorama):
> * Menu → Project → Align to Grid
> * Set Shooting configuration: /e.g./, Order: By row (top→bottom),

> Direction: Unidirectional (left→right always), Start at: Top Left)

> * Enter Grid dimensions (/e.g./, 5 rows× 14 columns)
> * Set overlap Spacing percentages (/e.g./, 30% in both H and V)
> * Orientation → Roll angle [tick] Do not change
> * Click “Apply”.  (Can now close that dialog.)
>
> * Left navigation → Optimizer
> * Set Anchor Image to middle image (/e.g./, 74 of 147)
>
> * Left navigation → Control Points
> * Menu → Control Points → Generate Control Points for all

> overlapping images, and wait until done
>

> * Left navigation → Optimizer
> * Click “Run Optimizer” and wait until done
>
> * Menu → Tools → Panorama Editor (to see result)
>
> * Left navigation → Create panorama
> → Adjust target filename to (/e.g./) PanA-pan.jpg
> * Click “Create panorama” button to stitch the panorama

> www.ptgui.com <http://www.ptgui.com>

>
> On 7/25/25 15:54, Mike Cowlishaw wrote:
> > Hi Joost,
> >
> > For non-spherical panoramas I typically use a hundred of more
> images and
> > therefore must use "Project -> Align to Grid" to avoid problems with
> > large areas of sky with just bits of trees, etc.  This works
> extremely
> > well, but I see some added roll in the aligned (and then stitched)
> > panorama.  It's only a few degrees but is very noticeable.
> >
> > The images I've used to show this (in subdirectory 'work') and the
> > resulting uncropped panoramas and the .pts files are in:

> > https://speleotrove.com/misc/MFC-20250617.zip <https://
> speleotrove.com/misc/MFC-20250617.zip>

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[Mike Cowlishaw]

John, thanks.   Using the image 'straight ahead' makes sense.   However, following the steps I detailed before, the anchor image does not seem to change (that is, if I change the anchor image from1 to the number of a middle image the result is identical .. i.e., with significant roll).  So my priority question is:  how do I set the anchor image?   Doing the obvious (changing the number on the Optimiser page) seems to have no effect.

It's also why I asked why 1 is the default anchor image .. in a landscape panorama it is unlikely to be the point of interest and is also very likely to be sky.

(As I mentioned .. the camera is always level: DJI's gimbals are good at that.) 

Mike

[Mike Cowlishaw]

See my post in reply to John:

" Using the image 'straight ahead' makes sense.   However, following the steps I detailed before, the anchor image does not seem to change (that is, if I change the anchor image from1 to the number of a middle image the result is identical .. i.e., with significant roll).  So my priority question is:  how do I set the anchor image?   Doing the obvious (changing the number on the Optimiser page) seems to have no effect.
It's also why I asked why 1 is the default anchor image .. in a landscape panorama it is unlikely to be the point of interest and is also very likely to be sky."

The exception is noted, although I never add control points nowadays {and I have no idea what you mean by 'level in second pass' :-)].

What I really want is a one-step (one button) process to do 'Align images' plus 'Create Panorama'.   Watching progress bars creep across their windows so I can then robotically press the second button is not a productive use of sitting in front of a computer...

Mike

[Erik Krause]

Am 30.07.25 um 16:13 schrieb Mike Cowlishaw:

> What I really want is a one-step (one button) process to do 'Align images'
> plus 'Create Panorama'.

Using a calibrated panoramic tripod head, it should be possible to batch
stitch well-shot panoramas using templates, reducing the number of
button presses required per panorama to less than one. However, any
imperfections in the shooting process, such as the head not being level
or not being properly adjusted to the no-parallax point, requires manual
intervention.

> Watching progress bars creep across their windows so I can then
> robotically press the second button is not a productive use of
> sitting in front of a computer

That's why the batch stitcher exists. Prepare a panorama and send it to
the Batch Stitcher once you're satisfied. While it stitches, prepare the
next one...

--
Erik Krause
http://www.erik-krause.de

[John Houghton]

Mike, The cause of the change in the roll parameter of the anchor image when Align Images is run lies in the Project Settings tab.  There is a Straighten panorama option which is enabled by default.  If that is unchecked, running Align Images does not change the orientation of the anchor image, but the resulting panorama is not quite level (but near enough?).  I had rejected this explanation because I had tried to run the straighten panorama option on the Edit menu of the Panorama Editor and this fails for your panorama, leaving the panorama image unchanged.   So I assumed the Straighten option in the Align Images function would also have failed to have any effect.  Achieving a level panorama automatically by linking all roll parameters in the optimization does result in a level panorama, with the roll parameter of all images being 0.02 degrees.  You may be happy with the very slightly unlevel panorama without bothering to do the roll linking.

John

[RoyReed]

" It's also why I asked why 1 is the default anchor image .. in a landscape panorama it is unlikely to be the point of interest and is also very likely to be sky."

The first image is likely to be the anchor image when you make a series of photos for a 360° equirectangular panorama.

[John Houghton]

On Wednesday, July 30, 2025 at 3:13:15 PM UTC+1 Mike Cowlishaw wrote:

. . . and I have no idea what you mean by 'level in second pass' :-)].

Levelling can be carried out in an optimization run by using horizontal and/or vertical line control points to identify features that ought to be truly horizontal or vertical:

For the Level in single pass, horizontal and vertical line points take part in the general optimization.  They can be used for levelling purposes and also by careful positioning for straightening curved lines.  Thus, they can be used to correct barrel distortion, say, or flatten the horizon when lens parameters are being evaluated.

For the Level in second pass, the horizontal and vertical points are ignored in the 1st pass in which the images are simply aligned with each other.  In a second pass, just the horizontal and vertical points alone are used to level the panorama, without having any effect on the way images align with each other.  In effect, the entire panorama is shifted as a single unit on the spherical stitching surface to achieve the levelling.

John

[Mike Cowlishaw]

Erik, thanks.   But for me it seems that the Align Images takes a lot longer than the stitching, and one has to finish that before starting the stitch.  So one is sitting in front of a PC that is 100% busy during that process.  One stitching has started I can go and do something else, anyway.  :-)

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[Mike Cowlishaw]

Roy -- thanks.   For clarification, I am not asking about 360° images for this problem (I take more of those, in truth, than 'flat' panoramas).   I have no problems at all with spherical images and usually just use the DJI-generated one which is only slightly worse that PTGui and nowadays equally detailed (a year or two ago they were much smaller than what PTGui would create).

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[Mike Cowlishaw]

John, OK, thanks, I'll try this ....

And thanks, too, for the explanation of levelling.

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[Mike Cowlishaw]

" Mike, The cause of the change in the roll parameter of the anchor image when Align Images is run lies in the Project Settings tab.  There is a Straighten panorama option which is enabled by default.  If that is unchecked, running Align Images does not change the orientation of the anchor image, but the resulting panorama is not quite level (but near enough?)."

John, unchecking 'Straighten panorama' worked perfectly, and yes, as level as I need.  Also much easier to crop the resulting image.

*Very*  many thanks.   Case closed, I think.

Mike

[Mike Cowlishaw]

A follow-up question:  on trying the above on a new (108-image) panorama .. the weird roll came back.  After some experiments on the smaller one I shared earlier, I found that:

• If 'Straighten panorama' is unchecked before applying 'Align to Grid' then the resulting aligned panorama has the dreaded roll of a couple of degrees.
  
  
• If 'Align to Grid' is applied before unchecking 'Straighten panorama' then the resulting aligned panorama is level.
  

I'm curious as to why there is this difference? 

Mike

[John Houghton]

Mike, I didn't find any difference between unchecking Straighten Panorama before or after running Align to grid.  If the image settings resulting from Align to grid match the actual shooting angles well, then the image in the Panorama Editor window should look pretty good already, and whichever image you select as the anchor image will not change its orientation as a result of running Align Images. (It should remain at 0.  Check by displaying the Image Settings tab).  But the positions and orientations of the other images may well change significantly, depending on the actual true roll value of the selected anchor image. 

John

[PTGui Support]

Hi Mike,

The ‘straighten panorama’ setting determines what is done during Align Images.

So you should uncheck it before running Align Images. Align to Grid ignores this checkbox.

Kind regards,

Joost Nieuwenhuijse

ptgui.com

On 4 Aug 2025, at 16:16, Mike Cowlishaw <mfc.s...@gmail.com> wrote:



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[John Houghton]

On Tuesday, August 5, 2025 at 8:03:30 AM UTC+1 PTGui Support wrote:

The ‘straighten panorama’ setting determines what is done during Align Images.

Joost, My tests suggest that when the Straighten option is checked, if that fails to work a Centre operation is performed instead. That seems to explain the puzzling results we were seeing.

John

[Mike Cowlishaw]

Now I've even more confused ... the order definitely made a difference when I tried it.  I do both before 'Align Images'.  Specifically, the steps I follow are:

Processing multi-row panoramas

Using ‘wizard’:

1. Load Images – select images to be used for the panorama (typically all in a single directory)

2. If a small panorama (e.g., little sky):
   • Click “Align Images” and wait until done
   • Click “Create Panorama”

1. • 
     → Adjust target filename to (e.g.) PanA-pan.jpg

1. • Click new “Create Panorama” button to stitch the panorama

1. • 
     → View → use default, to view

2. Otherwise (large panorama):

1. • Menu → Project → Align to Grid

1. • Set Shooting configuration: e.g., Order: By row (top→bottom), Direction: Unidirectional (left→right always), Start at: Top Left)
   • Enter Grid dimensions (e.g., 5 rows× 14 columns)

1. • Set overlap Spacing percentages (e.g., 30% in both H and V)

1. • Orientation → Roll angle [tick] Do not change

1. • Click “Apply”.  (Can now close that dialog.)

1. • Project Settings → uncheck ‘Straighten panorama’
   • Then as above (Align Images and Create Panorama).

Mike

[John Houghton]

Mike,  I think the difference between the two methods might be that when you use Align to Grid,  the assumption is that you are positioning the images reasonably accurately according to the known shooting angles, so Align Images doesn't attempt to interfere too much with the general positioning of the panorama.  Whereas, when Align Images has no idea where the panorama should end up, it optimizes with linked roll parameters at some point in order to level/straighten it or simply centres it.  Just a guess!

John

[PTGui Support]

That’s a complete workflow. Try it in isolation, I’m sure you’ll see that only Align Images will take this checkbox into account. Align to Grid ignores it.

Kind regards,

Joost Nieuwenhuijse

ptgui.com

On 5 Aug 2025, at 11:05, Mike Cowlishaw <mfc.s...@gmail.com> wrote:

Now I've even more confused ... the order definitely made a difference when I tried it.  I do both before 'Align Images'.  Specifically, the steps I follow are:

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[PTGui Support]

Hi John,

Do you have Fit Panorama enabled in the Project Settings? This performs a centre operation, which would explain what you are seeing.

Kind regards,

Joost Nieuwenhuijse

ptgui.com

On 5 Aug 2025, at 09:03, John Houghton <houghto...@gmail.com> wrote:



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[Mike Cowlishaw]

Hi Joost, you said:

"That’s a complete workflow. Try it in isolation, I’m sure you’ll see that only Align Images will take this checkbox into account. Align to Grid ignores it."

I'm sure you are right, but I don't know how to 'try it in isolation'.   

I've supplied the full process I use ('full workflow'?) because that's what reproduces the problem.  In particular, if the 'Straighten' option is unchecked before the 'Align to Grid' is applied the roll occurs.  If it is unchecked after the 'Align to Grid' is applied then everything comes out level.   

In both cases the two events occur before 'Align Images'.

I've used the same sequence on both the small panorama I shared at the start of this thread and also on a larger (108 images) one.  Same result: unchecking 'Straighten' before 'Align to Grid' ends up with a roll applied to the stitched image.  Unchecking it after 'Align to Grid' results in a level panorama. 

Mike

Mike

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[John Houghton]

On Tuesday, August 5, 2025 at 3:41:19 PM UTC+1 PTGui Support wrote:

Do you have Fit Panorama enabled in the Project Settings? This performs a centre operation, which would explain what you are seeing.

Joost, Yes, I left the Fit option checked.  But I regularly use Fit from the Panorama Editor menu and have never seen it centring the image.  It just shrinks the view to just accommodate the image.  I would not have occurred to me that Fit in Align Images might behave differently.  So thank you for that insight.

John

[Mike Cowlishaw]

Two experiments to report:

1. A 'full' panorama (108 images) that I took yesterday stitched very nicely using the workflow I listed above (it would have been about 97k pels wide, so I reduced to 65500).  If interested, it's the top of the list at: https://speleotrove.com/gallery/Kenilworth_Castle.html
   
   
2. On reading the recent comments I went back to the original test case that I shared at the start of this thread to try the 'Fit' option and the 'roll' had re-appeared (before I changed anything, so using exactly the same workflow).   After several experiments, I went back to square one, starting with just a directory of images,  and all was fine.  The only difference I can see is that the 'old' directory had a file called 'work3.pts' that I must have saved at some time.  Could it be that this file is being read/used even though I clicked 'New Project'?

Mike

[PTGui Support]

> was fine.  The only difference I can see is that the 'old' directory
> had a file called 'work3.pts' that I must have saved at some time.
> Could it be that this file is being read/used even though I clicked
> 'New Project'?

Hi Mike,

No, PTGui doesn't read any project files unless you open them explicitly.

[Mike Cowlishaw]

>     was fine.  The only difference I can see is that the 'old' directory
>     had a file called 'work3.pts' that I must have saved at some time.
>     Could it be that this file is being read/used even though I clicked
>     'New Project'?

No, PTGui doesn't read any project files unless you open them explicitly.

OK, thanks.  I didn't think it would :-).

So there must be something else ... but I think I'm done experimenting for now;  I have a workflow that works for 'fresh' panoramas and have quite a few to process.

Thanks all for the pointers and suggestions!

Mike

 

[Mike Cowlishaw]

With all the help from everyone here I was able to create my 'best ever' panorama, yesterday.  It's currently the first one listed/shown at:  https://speleotrove.com/gallery/Kenilworth_Castle.html

It's pushing the limits of the gimbal (DJI RS4 Mini), but I'm pleased with the results.  The image is 65370×22429 (close to the JPEG limit, and 1.47gigaPels) and about 516 MB.  Details are summarised there, with specific notes, checklist, etc. at  https://speleotrove.com/gallery/DJI_RS4_Mini_notes.html 

Suggestions for improvements would be most welcome!

Mike