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 Post subject: Banding issue
PostPosted: Thu Jul 10, 2014 9:12 am 
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The issue with banding has reared it's ugly head again. I had this issue a while ago (which I also posted earlier this year) with my 85mm AI manual lens and I fixed it with a lens profile I created with Adobe lens profiler but I am having similar issues with my 200mm lens (f2.8 70-200mm zoom set at 200mm). As you see below it doesn't seem to make much difference whether I use a lens profile or not I get this funny banding in the sky. The top image is with lens correction and the bottom is without.

I have tried different cutting, levels, with or without diamond, nothing seems to eliminate this issue. Colour anchors make a bit of a difference but it is still evident. I have even tried to manually change the vignetting settings with no results. It looks like it is a vignetting issue but my above tests indicate not.

I shot this scene 2 rows x 29 columns (58 images) at f5.0, 200mm using a T&C head. I have a HOYA UV filter and a lens hood attached. I import raw images into lightroom convert to DNG and perform the lens correction. There is a noticeable difference when I apply the lens correction so I know that the profile applied does something. Export to APG as 8bit TIFF. Camera is D800E

Does anyone have ideas what it might be? =(
Attachment:
File comment: With Lens Correction
With Lens Correction.jpg
With Lens Correction.jpg [ 1.82 MiB | Viewed 242 times ]

Attachment:
File comment: Without lens correction
Without lens correction.jpg
Without lens correction.jpg [ 1.82 MiB | Viewed 242 times ]


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 Post subject: Re: Banding issue
PostPosted: Sun Jul 13, 2014 2:36 am 
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I was just looking at the last post from Dude, is this a possible cause maybe I will not convert to DNG and leave as NEF or do RAW conversion in Capture Pro. I can't see that as a cause but I am willing to try anything.

Can someone from Kolor have a look at it, I would appreciate your feedback. I have added the images into my Dropbox for you to look at. I would like to know if it is a lens or shooting issue or stitching with my workflow or settings and more importantly how I can correct it. Overall I am very happy with the software it does a great job 90% of the time and usually when it doesn't work it's usually an issue with the image capture.

If anyone else is interested in having a look the link is https://www.dropbox.com/sh/vau5u9nrtldyr8w/AADTwnykgqfHoPyf7kwrNjK9a, I would like to see if other people are getting a similar result. The images are in DNG format as shot in 2 folders one with the lens profile added the other without. I have not made any other corrections. I have included the XML file as well.

Thank you, regards

Robert


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 Post subject: Re: Banding issue
PostPosted: Sun Jul 13, 2014 12:53 pm 
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Joined: Mon May 22, 2006 12:18 am
Posts: 7734
Location: Duesseldorf, Germany
I shot this scene 2 rows x 29 columns (58 images) at f5.0, 200mm using a T&C head.
[/quote]

Do you mean the Panoneed head?

Boley wrote:
I have a HOYA UV filter and a lens hood attached. I import raw images into lightroom convert to DNG and perform the lens correction. There is a noticeable difference when I apply the lens correction so I know that the profile applied does something. Export to APG as 8bit TIFF. Camera is D800E


Clearly vignetting. F:5 isn´t sufficient for avoiding vignetting on a 70-200mm zoom.

Put away the filter.

I strongly suggest to use CaptureOne Pro and have all the shots analyzed.

I also suggest to use C1´s most geniously LCC option: you need to shoot a frame by holding a
piece *white* plexiglass directly on the lens after you took the series.

In C1 LCC analyzes this frame regarding the lens´ ColorCastCorrection - which includes also vignetting
and dust.
Then you have a perfect *LensCast+vignetting Correction* profile for *this lens* regarding *this particuar shoot*.

I the workflow C1 uses this data to optimize the outcoming from the RAW converting.

It´s a tool i´d NEVER would stop using when it comes to really elaborated shoots.

Take care to have a perfectly clean disk of white Plexiglass. I have a 10x10cm
piece and always keep it protected when it´s not i use.

How to use:
https://www.youtube.com/watch?v=KBoSHz4kBKA

Klaus


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 Post subject: Re: Banding issue
PostPosted: Mon Jul 14, 2014 6:52 am 
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Joined: Tue Oct 15, 2013 9:13 am
Posts: 28
Thanks Klaus, very valuable information

Quote:
Clearly vignetting. F:5 isn´t sufficient for avoiding vignetting on a 70-200mm zoom.


Do you suggest not shooting at F5? I thought at least lightroom's correction although not very good (as the stitched image shows) would make some difference to the stitched image but clearly the problem is still there with or without correction. I still don't understand how ineffective the lens profile in LR is.


Quote:
Put away the filter.


I will try without the filter. Have you had any experience with UV filters?

Quote:
I strongly suggest to use CaptureOne Pro and have all the shots analyzed. I also suggest to use C1´s most geniously LCC option: you need to shoot a frame by holding a piece *white* plexiglass directly on the lens after you took the series.


That was the next thing I was going to try. Do you use C1 exclusively for all your raw handling?

Quote:
In C1 LCC analyzes this frame regarding the lens´ ColorCastCorrection - which includes also vignetting
and dust. Then you have a perfect *LensCast+vignetting Correction* profile for *this lens* regarding *this particuar shoot*.
I the workflow C1 uses this data to optimize the outcoming from the RAW converting.
It´s a tool i´d NEVER would stop using when it comes to really elaborated shoots.
Take care to have a perfectly clean disk of white Plexiglass. I have a 10x10cm
piece and always keep it protected when it´s not i use.


Do you actually take a photo of the white plexiglass rather than through it as I understand they suggest in the video.

Thanks once again for your help.

regards

Robert


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 Post subject: Re: Banding issue
PostPosted: Mon Jul 14, 2014 11:19 am 
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Joined: Mon May 22, 2006 12:18 am
Posts: 7734
Location: Duesseldorf, Germany
Boley wrote:

Thanks once again for your help.

regards

Robert



Hi Robert!

I suggest f8 or better f11.

I rarely use filters these days. When i do i use a rotating Lee filterholder and 10x10cm Lee filters or a
Hasselblad Pro Shade and gel filter from Kodak. So vignetting caused by filters are unlikely.

I take aditional shot through the plexiglass at the end of each series.

Look for a cean white wall and aim your lens against it from about 10 - 20m. Then take several shots by underexposing them.

This way you can see how the lens behaves regarding vignetting.

I suggest to use C1 - even not using LCC it provides good analyzation-routines for the lenses and huge dadabase.
All in all it´s more elaborated as LightRoom.

best, Klaus


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 Post subject: Re: Banding issue
PostPosted: Tue Jul 15, 2014 3:22 am 
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Joined: Tue Oct 15, 2013 9:13 am
Posts: 28
Thanks Klaus, as always full of great advice and information. I will do some more tests with C1 and the LCC as hopefully that will be the end of my woes.

Best regards

Robert


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 Post subject: Re: Banding issue
PostPosted: Wed Jul 16, 2014 11:17 am 
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Joined: Tue Jan 01, 2013 11:14 am
Posts: 24
Location: Herefordshire, UK
The only solution to vignette-induced banding that I have found is to use a panorama program that corrects for vignetting out of the box, for example Panoramastudio (70 euros) http://www.tshsoft.de. It has been confirmed on this forum in previous posts on this subject that Autopano Pro/Giga is incapable of correcting for radially symmetric variations. As a consequence and having invested in the full Kolor package I find myself using it only occasionally.


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 Post subject: Re: Banding issue
PostPosted: Wed Jul 16, 2014 12:23 pm 
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Joined: Mon May 22, 2006 12:18 am
Posts: 7734
Location: Duesseldorf, Germany
lovelace wrote:
It has been confirmed on this forum in previous posts on this subject that Autopano Pro/Giga is incapable of correcting for radially symmetric variations.


That´s not completely correct. I always stated that earlier versions of APG did a VERY fine job compensating those issues.

Basically i assume, that better compensation CAN be done - but first Kolor needs to realize the issue at all.

Each and every lens produces vignetting. No question at all. BUT: using a lens @ f:8 and f:11 means that vignetting becomes hardly
visible with good lenses.

I had the experience that the VERY SAME LENS - my 1,4/85mm Nikon - NEVER had issues regarding vignetting BEFORE Kolor changed from Smartblend to what it is now.

All in all the new blending clearly gives better results than Smartblend. But at the same time the compensation of even minimal vignetting
became worse than it was before.

My strategy - which i never needed to do before - is: i process all my images carefully regarding vignetting in CaptureOne Pro before stitching.

I use the option of having C1 create a LCC-file for each shooting session - doing an additional shot by holding a piece of white plexiglass firmly on the front-lens. This shot is used in C1 for analysing the lenses behavior regarding color-cast, dust and vignetting.
The LCC - Lens Cast Calibration - profile is extremely helpful for achieving excellent image-quality before stitching.

Of course the base for all this is determined by the basic-quality of the lens . . . You cannot make a mediocre lens a brilliant one by using software.

Klaus


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