Blown highlights

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Jean M

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May 31, 2021, 5:05:13 AM5/31/21
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Hello group.

I experience blown highlights when stitching (Not HDR)
I shoot interior and the window/balcony views are over exposed unlike the originals. I tested with RAW (CR2 Canon) and TIFF (CR2 to TIFF generated by Canon "Digital Photo Professional" software). The same result. Unusable images.

What could be the problem?

Here is a "Wetransfer" link of both projects and files (1.7GB), expiring in 7 days.


Thank you for any assistance.
Jean Massry.

hgol...@gmail.com

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May 31, 2021, 10:16:31 AM5/31/21
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I've noticed the same issue.

PTGui Support

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May 31, 2021, 10:38:13 AM5/31/21
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Hi Jean,

This happens because you used automatic exposure. The balcony facing
shot is taken at 1/100s, the others are taken at 1/8.

PTGui will adjust them to some average value, so the interior shots will
be brightened and the window facing shot will be darkened.

You can reduce the overall exposure in the Post Processing tab. If you
dial in a -1.8EV exposure offset, the balcony will not be overexposed,
but of course the interior will be even darker. Enabling tone mapping
would be the better alternative here.

Kind regards,

Joost Nieuwenhuijse
www.ptgui.com
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PTGui Support

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May 31, 2021, 10:39:33 AM5/31/21
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I should add: it's generally best to shoot manual exposure. For scenes
like these use bracketing and enable tone mapping.

Kind regards,

Joost Nieuwenhuijse
www.ptgui.com

jmassry

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May 31, 2021, 10:51:09 AM5/31/21
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Thank You.
I have something to play with now. I didn't know about that.
BTW, I do shoot manual bracketed shots, but even making my HDR (Photomatix) before stitching in PTGui was giving the same issue, so i thought to test original photos from camera straight to PTGui to avoid sources of errors, and on purpose I gave only the dark brackets to PTGui to just stitch, nothing else, I didn't expect it will try to in somehow to paly with exposures.
Thanks again.


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jmassry

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May 31, 2021, 11:41:57 AM5/31/21
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I tried to do a few things as suggested, but it's trial and error. The preview is not like the result and the result is never pleasing.
Not my workflow.
Isn't there a way to simply tell PTGui to just stitch, and a basic function or a check box to ignore any AI functionality?
I would like to get my photo stitched back the same way I feed them to PTGui. I do my pre or post at my ease.
I guess it is not too much to ask, maybe it is somewhere hidden, I was expecting this to be obvious (default)

As shown in my photos examples, I shoot manual bracketed photos, but not all sides of the 360 have the same bracketed exposure, that's why you see 1/8 for all other photos (all being the darkest of their series) and 1 photo for the exterior the way I want it to look, it is also the darkest of its series but at a different exposure brackets. I don't necessarily use all the photos of the series, I decide what I use separately.

I am trying to find my workflow, just upgraded to the Pro version of PTGui and I wanted to decide what I like more, HDR first then stitch, or stitch then HDR (HDR by Photomatix, or Photoshop, ...)

I was so pleased with Masking and View Point Optimization but disappointed with the stitching behavior.
Awaiting so good news.

PTGui Support

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May 31, 2021, 12:19:09 PM5/31/21
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There is no AI in PTGui, the stitcher and blender are quite dumb actually.

But please see the attachment: if you stitch your images without any
adjustments (no blending, no exposure correction) this is what you get.
What I mean is this: if you want a seamless image, PTGui will need to
touch those exposures.

The contrast in this scene is huge, you might be expecting too much from
PTGui. Tone mapping or exposure fusion will not be able to compress the
dynamic range without creating a very artificial looking image.

You might try loading all bracketed images in PTGui and outputting the
HDR panorama as an .exr file. This image will contain the full dynamic
range of the scene, entirely unmodified. PTGui will not do any
significant exposure adjustments, just some minor adjustments at the
edges to make a seamless image.

Then, you can tone map this exr file in any HDR capable application. A
dedicated HDR application like Photomatix or SNS might give you results
you like.

Kind regards,

Joost Nieuwenhuijse
www.ptgui.com

> www.ptgui.com <http://www.ptgui.com>
>
> On 31/05/2021 16:16, hgol...@gmail.com
> <mailto:hgol...@gmail.com> wrote:
> > I've noticed the same issue.
>
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TIFF.jpg

jmassry

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May 31, 2021, 12:31:36 PM5/31/21
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Ok Thank you.
Yes the result as you showed me I don't like the exterior part.
I will try blending hdr and stitching all together in PTGui to see how it comes out, but in first place I showed up here because I had the same problem when I beautifully blended my individual parts of the panorama in Photomatix, then PTGui stitcher did the same for the exterior, there was no high contract in the seen after my HDR work yet final stitched panorama was not satisfactory.
I will try this tomorrow though, and see if the new workflow is good for me, otherwise I might post my HDR work for you to stitch and justify the result if not as expected.
Best regards.

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John Houghton

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May 31, 2021, 1:42:23 PM5/31/21
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 I tried manufacturing two exposure sets of images (for 1/8 and 1/80sec) from the raws for pseudo HDR processing.  The blended result from PTGui was poor but I generated the two blend planes and merged in SNS-HDR and got quite a respectable result with so-so quality.

John


highlights.jpg

jmassry

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May 31, 2021, 2:09:26 PM5/31/21
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Wow, this looks great, I really like it. I am mainly looking at the exterior, very much like what I want. As for the interior I have already a separate set with good quality, no worries about noise.

How did you do the process for this look? I didn't quite get your explanation.
Thank you in advance John.
Jean.


John Houghton

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May 31, 2021, 2:56:46 PM5/31/21
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On Monday, May 31, 2021 at 7:09:26 PM UTC+1 jma...@gmail.com wrote:
Wow, this looks great, I really like it. I am mainly looking at the exterior, very much like what I want. As for the interior I have already a separate set with good quality, no worries about noise.

How did you do the process for this look? I didn't quite get your explanation.

Jean, In principle, it was simply to convert the raw images to two sets of 16bit tiffs that might have been obtained by shooting bracketed shots in manual mode - i.e. one set at 1/8 sec and another set at 1/80.  I simply adjusted the exposure in the raw conversions.  These were then loaded into PTGui (then suitably ordered - 1/8, 1/80, 1/8, 1/80, 1/8 ....) and the exposure settings adjusted on the Image Parameters tab to enable PTGui to recognise that there were indeed five sets of bracketed images. Right click on the Source Images tab and select "Link HDR Bracketed Exposures".  After aligning the images, you can select Blend Planes for output creation to produce two equirectangular panorama images.  These can then be merged in an external HDR/Fusion program.

John
 

Erik Krause

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May 31, 2021, 5:27:56 PM5/31/21
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Am 31.05.2021 um 11:05 schrieb Jean M:
> Here is a "Wetransfer" link of both projects and files (1.7GB), expiring in
> 7 days.
>
> https://wetransfer.com/downloads/a01be717d06f4bdf21705ff2a3f14b1d20210531084850/a7680af01996ecaad764ebbb05efd2e220210531084911/727c7f

I gave it a try as well. I didn't use pseudo HDR but simply developed
the raw images (in ACR) such that they roughly match in brightness and
preserve the dynamic range. The outside view is masked in PTGui such
that (if possible) only the landscape and the floor is used, since the
interior walls got pretty washed. Find the result attached.


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http://www.erik-krause.de
_MG_4907 Panorama.jpg

jmassry

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Jun 1, 2021, 12:05:52 AM6/1/21
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Thank you all.
I will try to work on this tonight.

But IMHO, and because I do my HDR of 5 bracketed photos merging before PTGui, I still believe it is too much to do to solve such an issue, rather, have a checkbox in PTGui telling it Just stitch and don't touch anything else :)  because PTGui is giving the same problem blowing highlights of a very good blended HDR photos.
Cheers,


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PTGui Support

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Jun 1, 2021, 2:27:07 AM6/1/21
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That checkbox exists. If you don't want PTGui to touch your exposures,
do this in the Blending sidebar of the Panorama Editor:

- uncheck 'Exposure Compensation'
- uncheck 'Find Optimum Seams' *)
- Blender: 'Don't blend'

*) find optimum seams only works well if the images have the same
exposure, or if exposure compensation is enabled

Kind regards,

Joost Nieuwenhuijse
www.ptgui.com

On 01/06/2021 06:05, jmassry wrote:
> Thank you all.
> I will try to work on this tonight.
>
> But IMHO, and because I do my HDR of 5 bracketed photos merging before
> PTGui, I still believe it is too much to do to solve such an issue,
> rather, have a checkbox in PTGui telling it Just stitch and don't touch
> anything else :)  because PTGui is giving the same problem blowing
> highlights of a very good blended HDR photos.
> Cheers,
>
>
> On Tue, Jun 1, 2021 at 12:27 AM Erik Krause <erik....@gmx.de
> <mailto:erik....@gmx.de>> wrote:
>
> Am 31.05.2021 um 11:05 schrieb Jean M:
> > Here is a "Wetransfer" link of both projects and files (1.7GB),
> expiring in
> > 7 days.
> >
> >
> https://wetransfer.com/downloads/a01be717d06f4bdf21705ff2a3f14b1d20210531084850/a7680af01996ecaad764ebbb05efd2e220210531084911/727c7f
> <https://wetransfer.com/downloads/a01be717d06f4bdf21705ff2a3f14b1d20210531084850/a7680af01996ecaad764ebbb05efd2e220210531084911/727c7f>
>
> I gave it a try as well. I didn't use pseudo HDR but simply developed
> the raw images (in ACR) such that they roughly match in brightness and
> preserve the dynamic range. The outside view is masked in PTGui such
> that (if possible) only the landscape and the floor is used, since the
> interior walls got pretty washed. Find the result attached.
>
>
> --
> Erik Krause
> http://www.erik-krause.de <http://www.erik-krause.de>
>
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jmassry

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Jun 1, 2021, 3:06:46 AM6/1/21
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Ok great news,
Thank you very much.
I was playing with those options but didn't get the correct combination.
Will try tonight.
Cheers to PTGui.


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jmassry

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Jun 1, 2021, 11:02:12 AM6/1/21
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Thank you PTGui.
The following worked for me ('Multiband' instead of 'Don't blend')

- uncheck 'Exposure Compensation'
- uncheck 'Find Optimum Seams'  *)
- Blender: ' Multiband '

Best Regards.

Erik Krause

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Jun 1, 2021, 1:07:32 PM6/1/21
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Am 01.06.2021 um 06:05 schrieb jmassry:

> PTGui is giving the same problem blowing highlights of a
> very good blended HDR photos.

The easiest and probably the quickest workflow would be to follow the
recommendation and shoot your bracketed sets all with the same exposure
pattern.

Even if you feed tonemapped HDR images into PTGui those images are still
standard low dynamic range images, and if they are differently exposed
PTGui will need to adjust exposure (which might cause over- or
underexposure in certain frames) in order to get a seamless stitch.

Shoot the same exposure sequence for all frames, even if this gives you
a lot of completely underexposed images. Then load them all into PTGui
and let it do it's magic.
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