Author Topic: 7-Shot Panorama and Long Exposure  (Read 4332 times)

Marco Lanciani

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7-Shot Panorama and Long Exposure
« on: September 02, 2015, 16:20:05 »
Bringing my Panorama experience to next level.. Here’s an experiment with an almost easy subject. Moving elements are not friends for Panorama and I consider this a decent result.
Each shot was taken at f16 for 15" exposure on a 60mm lens. B+W 10 stop ND filter.

Maybe a longer exposure would have helped in getting a more textureless sea surface: I still think I was lucky with the clouds.
Marco Lanciani

Akira

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Re: 7-Shot Panorama and Long Exposure
« Reply #1 on: September 02, 2015, 18:09:32 »
Interesting and seemingly promising concept, Marco.  As you say, longer exposure would have been more desirable, but the beautiful blueish greenish tones of the sea and the sky, and their subtle color unevenness are great material for the abstraction.

Am looking forward to further postings!
"The eye is blind if the mind is absent." - Confucius

"Limitation is inspiration." - Akira

Marco Lanciani

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Re: 7-Shot Panorama and Long Exposure
« Reply #2 on: September 03, 2015, 00:20:12 »
Thank you, Akira.
I still have a few free days here at the sea: I'll try to develop the concept.

BTW, it was stitched in PTGui.  ;)
Marco Lanciani

Akira

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Re: 7-Shot Panorama and Long Exposure
« Reply #3 on: September 03, 2015, 03:28:54 »
BTW, it was stitched in PTGui.  ;)

Yes, I guessed it.  I'm curious whether such images are unexpectedly challenging or all-too easy for the stitching software.
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simsurace

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Re: 7-Shot Panorama and Long Exposure
« Reply #4 on: September 03, 2015, 14:37:36 »
Very interesting minimalistic shot. Nice colors!

There appears to be a seam slightly to the left of the center, but I cannot be sure based on this low-res version. There might be some way to smooth it out a little bit by exporting to a layered TIF or PSD file and manually masking the different layers. Maybe a simple gradient mask will do the job, such that the transition from the shiny to the matte region of the water surface is more gradual.
Simone Carlo Surace
suracephoto.com

Akira

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Re: 7-Shot Panorama and Long Exposure
« Reply #5 on: September 03, 2015, 15:06:20 »
There appears to be a seam slightly to the left of the center, but I cannot be sure based on this low-res version. There might be some way to smooth it out a little bit by exporting to a layered TIF or PSD file and manually masking the different layers. Maybe a simple gradient mask will do the job, such that the transition from the shiny to the matte region of the water surface is more gradual.

Simone, are you referring to the slight discontinuity of the texture on the surface of the sea?  Would that be a seam?
"The eye is blind if the mind is absent." - Confucius

"Limitation is inspiration." - Akira

simsurace

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Re: 7-Shot Panorama and Long Exposure
« Reply #6 on: September 03, 2015, 15:46:20 »
There appears to be a seam slightly to the left of the center, but I cannot be sure based on this low-res version. There might be some way to smooth it out a little bit by exporting to a layered TIF or PSD file and manually masking the different layers. Maybe a simple gradient mask will do the job, such that the transition from the shiny to the matte region of the water surface is more gradual.

Simone, are you referring to the slight discontinuity of the texture on the surface of the sea?  Would that be a seam?

Yes. I'm not sure what it is, but I've had similar problems in panos of water surfaces. The stitching software has to make the mask somewhere but it is kind of random when the texture is so chaotic. From my experience, the masks that PTGui draws are all hard. If the surface is is shinier on one shot than the other, there will be a rather sharp transition which looks like a seam, i.e. you see where the transition between images occurs. In that case, manually retouching the masks is necessary.
Simone Carlo Surace
suracephoto.com

Akira

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Re: 7-Shot Panorama and Long Exposure
« Reply #7 on: September 03, 2015, 15:51:07 »
I see.  Thanks for sharing your observation of the stitching character of PTGui.  According to your evaluation, Photomerge of CC2015 seems to handle the random patterns more naturally.  I haven't yet seen any clear seams of the stitched clouds or running rivers.
"The eye is blind if the mind is absent." - Confucius

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simsurace

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Re: 7-Shot Panorama and Long Exposure
« Reply #8 on: September 03, 2015, 16:23:30 »
I see.  Thanks for sharing your observation of the stitching character of PTGui.  According to your evaluation, Photomerge of CC2015 seems to handle the random patterns more naturally.  I haven't yet seen any clear seams of the stitched clouds or running rivers.

My wild guess is that they use the "Content Aware" algorithms to help out. Sadly, Photomerge doesn't allow the fine control of the geometry of the projection that is possible in PTGui.
Simone Carlo Surace
suracephoto.com

Akira

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Re: 7-Shot Panorama and Long Exposure
« Reply #9 on: September 03, 2015, 16:37:38 »
Thanks, Simone, for your further assessment of the software.  Yes, the preset-only geometry correction is limiting.  But I've found it an added bonus of CC2015.  The limitation is largely helped by the tripod.
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Marco Lanciani

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Re: 7-Shot Panorama and Long Exposure
« Reply #10 on: September 03, 2015, 20:44:47 »
Simone, thank you for your comment.
Yes, there's a seam where you say and it's probably the most visible. I think there is also some problems in the sky along the seams: they are best viewed on the small picture. Probably that seams are due to vignetting on each single frame.
In this case I corrected vignetting in LR: asking the support, they suggest not to correct lens vignetting in the RAW Developer and simply let PTGui do the job... Seams due to vignetting is something you can view only when stitching an even featureless sky. I tried this the first result was not good but PTGui has inside the right tools to correct this and then I almost succeeded... I say almost because I'm not totally content with the result.

I still think PTGui blender - Version 10.0.12 - has still some problems on blending even featureless elements like a sky.

IMO PTGui is still the best stitcher but its blender is definitely not the best out there. I hope this will change soon... ::)
There's stil a plugin for PTGui, Smartblend; IMO the best blender available. Unfortunately it's not directly usable in PTGui on Mac, even though there's a trick to make it usable also on Mac.
Anyway it's not an option for me: too slow!

Photomerge is an excellent blender one of the best at the moment: One could do the stitching in PTGui, then export the result in layers, instead of the blended panorama, and blend them later in PS.
Obviously this is possible only with small panoramas; a powerful computer can help; I have no idea how many layers in a single image can handle PS but my guess is that gigapixel panoramas are out of reach, anyway.
Marco Lanciani

simsurace

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Re: 7-Shot Panorama and Long Exposure
« Reply #11 on: September 04, 2015, 10:32:58 »
Simone, thank you for your comment.
Yes, there's a seam where you say and it's probably the most visible. I think there is also some problems in the sky along the seams: they are best viewed on the small picture. Probably that seams are due to vignetting on each single frame.
In this case I corrected vignetting in LR: asking the support, they suggest not to correct lens vignetting in the RAW Developer and simply let PTGui do the job... Seams due to vignetting is something you can view only when stitching an even featureless sky. I tried this the first result was not good but PTGui has inside the right tools to correct this and then I almost succeeded... I say almost because I'm not totally content with the result.

I still think PTGui blender - Version 10.0.12 - has still some problems on blending even featureless elements like a sky.

IMO PTGui is still the best stitcher but its blender is definitely not the best out there. I hope this will change soon... ::)
There's stil a plugin for PTGui, Smartblend; IMO the best blender available. Unfortunately it's not directly usable in PTGui on Mac, even though there's a trick to make it usable also on Mac.
Anyway it's not an option for me: too slow!

Photomerge is an excellent blender one of the best at the moment: One could do the stitching in PTGui, then export the result in layers, instead of the blended panorama, and blend them later in PS.
Obviously this is possible only with small panoramas; a powerful computer can help; I have no idea how many layers in a single image can handle PS but my guess is that gigapixel panoramas are out of reach, anyway.

Unfortunately my knowledge of the workings of the various blenders is very superficial.
If the vignetting correction were perfect, the blender would not need to adjust anything about the exposures. The vignetting correction is seldom correct.
What we need is a tool in PTGui which allows us to draw a curve along which the exposure should be constant. This would allow us to draw a straight line along the top of the frame where the sky is, and the resulting pano will have a uniformly bright sky along this line.

What I was referring to in my posts above was that the masks that PTGui outputs (are they part of stitching or blending, I'm not sure?) are (as far as I've seen the few times I've exported all the layers instead of the flattened panorama) either/or, such that for any pixel in the final panorama, only one of the stitched images is used. What I suggest is softening these masks to make them slightly transparent, such that in the zone where the sea changes from being shiny to being matte, you have a mixture. This will make the transition almost disappear. Since the surface of the sea has a fractal nature, mixing different images should not be immediately apparent to the eye.
Simone Carlo Surace
suracephoto.com