Banding

[Boley]

Banding

by Boley » Thu Feb 20, 2014 1:42 am

Can anyone suggest why I may getting this vertical banding on my stitched panorama (see below)

Vertical banding, top to bottom

I have tried many things but I just can't get rid of this banding. I have played around with various blend settings 0, +10-, -10 and all values in between, diamong cutting, etc. I have even tried the 3.5 beta version and the new ISO and Smart settings. I don't believe it's the way I have taken the photos or the equipment but rather something that I am or not setting in APG.

My equipment and workflow is:

- Lens: Nikkor AI-S MF 85mm/f1.4 shot at f16
- All manual settings - Focus, aperture, shutter, ISO & WB
- Used motorised Panohead
- 87 raw images, 3 rows, 29 columns. Sequence was column by column left to right (normally I shoot row by row)
Photographed late afternoon, light was consistent.

- Import into LR, converted to DNG
- No corrections but have also tried lens correction to eliminated vigetting but made no difference either way
- Export via APG plugin as TIFF. Tried both 8 and 16bit with no difference
- Used papywizard plugin with XMF files from pan head data

Stitching excellent at detection. I should also say that I did three three sessions, 87, 203, 116 images all with similar banding issues.

Any thoughts at what I need to try?

[lumelix]

Re: Banding

by lumelix » Thu Feb 20, 2014 10:02 am

Hi
This is caused by vignetting by the lens. APG don't corrects vignetting, you must remove it in an external program.

[Boley]

Re: Banding

by Boley » Thu Feb 20, 2014 10:21 am

Hi Martin, I did that in LR and I get the same result whether I correct for vignetting or not.

I wonder if anyone using this lens is encountering the same problem.

Robert

[lumelix]

Re: Banding

by lumelix » Thu Feb 20, 2014 10:31 am

Hi Robert
You can check if there is still some vignetting visible in the Images from LR.
But two Images of the upper row side by side in an Image Editor and move them one above the other.
Then you can see some differences from vignetting very easily.

The MF 85 mm should not be a Problem, but I suggest only use to f/8. With f/16, you loose sharpness because of diffraction.

[Boley]

Re: Banding

by Boley » Thu Feb 20, 2014 11:28 am

Thanks Martin, yes there still appears to be some vignetting but quite minor, certainly better than without the correction. The problem may be that LR did not have a profile for this exact lens and had to use one for a AF lens which obviously is not the same.

I have searched for the correct profile but was not able to find one, not even on the Nikon site .

With vignetting, wouldn't you also get it at the top and bottom of the image. On these panos it only seems to appear on the sides.

Do you think that shooting at f8 would perhaps reduce some of this vignetting?

It would be a pity if I am unable to correct this problem as I really like using this lens.

Thanks for your advice.

Robert

[Destiny]

Re: Banding

by Destiny » Thu Feb 20, 2014 11:35 am

Hi.. You really need to search out your lens specs to find the best f-stop to use to avoid as much Vig' as possible... Some lenses have huge issuing with Vig'..

Have you tried to process your images using the APG plugin, which will remove some Vig' prior to stitching.... Just open up the plugin and process all images the same...

Destiny..

PS.. You might look at testing out f4...

[Boley]

Re: Banding

by Boley » Thu Feb 20, 2014 11:49 am

Thanks, I haven't tried that but I'm willing to give it a go.

I didn't think APG corrected vignetting

Robert

[Destiny]

Re: Banding

by Destiny » Thu Feb 20, 2014 11:54 am

Its hear Robert...

Destiny..

Attachments

[klausesser]

Re: Banding

by klausesser » Thu Feb 20, 2014 11:55 am

Hi Robert
You can check if there is still some vignetting visible in the Images from LR.
But two Images of the upper row side by side in an Image Editor and move them one above the other.
Then you can see some differences from vignetting very easily.

The MF 85 mm should not be a Problem, but I suggest only use to f/8. With f/16, you loose sharpness because of diffraction.

Diffraction doesn´t cause banding

The lens does not vignet remarkably enough @8/11 at all to cause a stitcher to produce banding in the rendering. I always use f8 or f11.

I never had issues with banding with the lens in earlier versions of APG. I mean it came up with 2.6. and stayed until now. But i mean it´s a bit better in 3.5 - need to run a dedicated test.

Usually small rest of vignetting must get compensated by the stitcher - as PTGui does very well. That´s why i use PTGui when i use the 85mm with blue skies. NO banding here.

Klaus

[lumelix]

Re: Banding

by lumelix » Thu Feb 20, 2014 11:58 am

Hi Robert
You can create a new Profile for your MF Lens with Adobes Lens Profile Creator, if you couldn't find the correct Profile.

http://www.adobe.com/support/downloads/ ... ftpID=5490

It's clear that vignetting isn't the same as with the AF-Versions because the aperture is modified (9 rounded instead of straight blades).
I suggest to take some Pictures of blue sky at f4, f5.6, f8 and f11 and then create with these Images the new Profile.
Should not be a Problem to get this issue solved. And it is worth the effort, this lens is one of the best ever made by Nikon ( http://www.kenrockwell.com/nikon/85mm-f14.htm )!

[klausesser]

Re: Banding

by klausesser » Thu Feb 20, 2014 12:07 pm

Do you think that shooting at f8 would perhaps reduce some of this vignetting?
It would be a pity if I am unable to correct this problem as I really like using this lens.
Thanks for your advice.

Robert

Hey Robert!

Did you try the anchors? The color-corection should help to solve this issue. Did you try APG 3.5 ( yes - sorry, i overread it)

The lens doesn´t produce that much vignetting it can be an issue for the stitcher. It´s definitely an excellent lens.

As said: in PTGui i don´t have issues with banding at all using this 1.4/85mm and the 1.8/85mm. Also i didn´t have issues with banding
with APG versions which used Smartblend. With this versions i tested lenses which definitely produced lots of vignetting - which was compensated very well.

In APG 3.5 the seem to use different strategies for lens-correction (who knows . . ) and i have a feel that here banding is less of a problem.

So: which version nof APG did you use in this case?

I suggest to NOT use LR for treating vignetting.

best, Klaus

Last edited by klausesser on Thu Feb 20, 2014 12:15 pm, edited 1 time in total.

[klausesser]

Re: Banding

by klausesser » Thu Feb 20, 2014 12:12 pm

Should not be a Problem to get this issue solved. And it is worth the effort, this lens is one of the best ever made by Nikon ( http://www.kenrockwell.com/nikon/85mm-f14.htm )!

Right: this lens definitely is excellent!

I wouldn´t try to treat vignetting in any way. It´s up to the stitcher to compensate it! Treating vignetting in dedicatd apps
means to confuse the stitcher´s corrections because the overlap! No lens-correction app knows about the overlap!!

So NO PREVIOUS LENS CORRECTION AT ALL - besides the one inside APG!

best, Klaus

[Boley]

Re: Banding

by Boley » Thu Feb 20, 2014 12:39 pm

Thanks Klaus, very valuable information. I will try the lens correction in APG and then also PTGui and see how I go.

It's a great lens and I am sure I will overcome this problem. Now that I have got a consensus from everyone that the problem is vignetting I know where to focus, so to speak. Once you establish the problem there's usually a solution - one way or another.

Thanks to everyone who made a valuable contribution, greatly appreciated.

Robert

[mediavets]

Re: Banding

by mediavets » Thu Feb 20, 2014 12:43 pm

Thanks Klaus, very valuable information. I will try the lens correction in APG and then also PTGui and see how I go.

Robert

As I recall PTGui incorporates vignetting correction code 'borrowed' from the Hugin project.

AFAIK APP/APG do not have vignetting correction.

[klausesser]

Re: Banding

by klausesser » Thu Feb 20, 2014 12:58 pm

Now that I have got a consensus from everyone that the problem is vignetting I know where to focus, so to speak.

Hi Robert!

To be honest: i´m not convinced that it´s vigneting. Vignetting is caused by the optical construction of a lens or by sunshades, filters or so.
THIS lens doesn´t show visibly obvious vignetting @8 or 11 (there´s no lens without vignetting - the question is the visibility of it).

The fact that PTGui doesn´t produce banding with the very same lens shows us: it´s not a lens-vigentting issue.

Several users mentioned banding-issues - they all used different lenses but had very familiar issues with banding.

So: in my eyes it´s NOT the lens.

best, Klaus

btw.: are you living in Australia? Did we get in contact via Josef?

[klausesser]

Re: Banding

by klausesser » Thu Feb 20, 2014 1:02 pm

Thanks Klaus, very valuable information. I will try the lens correction in APG and then also PTGui and see how I go.

Robert

As I recall PTGui incorporates vignetting correction code 'borrowed' from the Hugin project.

AFAIK APP/APG do not have vignetting correction.

PTGui and HugIn both are GUIs for the Panotools afaik - but PTGui /Pro is much more advanced than the free HugIn.

best, Klaus

[klausesser]

Re: Banding

by klausesser » Thu Feb 20, 2014 1:07 pm

It seems that the banding occurs only horizontal - not vertical . .

Given that the camera is mounted in portrait-mode and because the horizontal FOV is the smallest then . . . banding can impossibly be caused by vignetting then.

Klaus

[lumelix]

Re: Banding

by lumelix » Thu Feb 20, 2014 1:13 pm

Banding because of vignetting depends from overlapping. Seems that in this case overlapping horizontally is better than vertically to avoid vigneting issues.
I found always vignetting issues with APG even using a 600mm tele at f8, when overlapping is really small (less than 20%).
If overlapping is more than 25%, there is enough area to Clip away the strongest vignetting and avoid banding.

Last edited by lumelix on Thu Feb 20, 2014 1:16 pm, edited 1 time in total.

[mediavets]

Re: Banding

by mediavets » Thu Feb 20, 2014 1:14 pm

Thanks Klaus, very valuable information. I will try the lens correction in APG and then also PTGui and see how I go.

Robert

As I recall PTGui incorporates vignetting correction code 'borrowed' from the Hugin project.

AFAIK APP/APG do not have vignetting correction.

PTGui and HugIn both are GUIs for the Panotools afaik - but PTGui /Pro is much more advanced than the free HugIn.

best, Klaus

See: http://www.ptgui.com/panotools.html

"PTGui started in 2001 as a Graphical User Interface for Panorama Tools, hence the name. Panorama Tools, originally written by Helmut Dersch, was the most versatile package for creating panoramic images at that time. ............

.........Over the years nearly all functionality of Panorama Tools has been integrated into PTGui and Panorama Tools is no longer needed to run PTGui, but the Panorama Tools optimizer and stitcher can still be used.

Also: http://www.tawbaware.com/forum2/viewtopic.php?t=4704

https://groups.google.com/forum/#!topic ... dIaFwDaupI

http://hugin.sourceforge.net/docs/manua ... tting.html

Last edited by mediavets on Thu Feb 20, 2014 1:25 pm, edited 2 times in total.

[klausesser]

Re: Banding

by klausesser » Thu Feb 20, 2014 1:18 pm

Banding because of vignetting depends from overlapping. Seems that in this case overlapping horizontally is better than vertically to avoid vigneting issues.
I found always vignetting issues with APG even using a 600mm tele at f8, when overlapping is really small (less than 20%).

IF a lens produces vignetting at all - it´s on the far ends of the frame. That means: IF the long side of the frame shows vignetting, then the short side must be showing much heavier vignetting ;-)
When the camera is mounted in portrait-mode the vignetting must be visible not as vertical stripes but as horizontal stripes in that case.
best, Klaus

Last edited by klausesser on Thu Feb 20, 2014 1:25 pm, edited 1 time in total.

[klausesser]

Re: Banding

by klausesser » Thu Feb 20, 2014 1:20 pm

See: http://www.ptgui.com/panotools.html

"PTGui started in 2001 as a Graphical User Interface for Panorama Tools, hence the name. Panorama Tools, originally written by Helmut Dersch, was the most versatile package for creating panoramic images at that time. ............

.........Over the years nearly all functionality of Panorama Tools has been integrated into PTGui and Panorama Tools is no longer needed to run PTGui, but the Panorama Tools optimizer and stitcher can still be used.

Also: http://www.tawbaware.com/forum2/viewtopic.php?t=4704

Well - and what´s that supposed to tell us in terms of the issue we talk about here?

best, Klaus

P.S.: you see - when PTGui can deal perfectly wit the lens without banding - why would APG fail?

[lumelix]

Re: Banding

by lumelix » Thu Feb 20, 2014 1:33 pm

IF a lens produces vignetting at all - it´s on the far ends of the frame. That means: IF the long side of the frame shows vignetting, then the short side must be showing much heavier vignetting ;-)
When the camera is mounted in portrait-mode the vignetting must be visible not as vertical stripes but as horizontal stripes in that case.
best, Klaus

Hi Klaus
Yes, this is in theory
But I always shot Portrait mode, and if it occurs, always have this banding vertically, on the short (!?) side of the Images. It's typically if you use APG with images that have vignetting. Could be also dependend of the algorithmus of the blending engine in APG. Perhaps, PTGui have a better solution there.

If you read destinys post about "the best stitcher", you can see that I'm not happy with the blending engine, still not also in V3.5b2.

Last edited by lumelix on Thu Feb 20, 2014 1:36 pm, edited 2 times in total.

[mediavets]

Re: Banding

by mediavets » Thu Feb 20, 2014 1:35 pm

Well - and what´s that supposed to tell us in terms of the issue we talk about here?

best, Klaus

It tells us that PTGui is no longer simply a GUI-front end to Panorama Tools and has not been for many years now. It now incorporates ideas from many other sources.

P.S.: you see - when PTGui can deal perfectly wit the lens without banding - why would APG fail?

Because PTGui incorporates vignetting correction and APG does not (yet); it also has different colour correction and blending systems/'engines'.

[klausesser]

Re: Banding

by klausesser » Thu Feb 20, 2014 1:52 pm

Yes, this is in theory

No, sorry. That´s practise. And it´s nothing but logic

But I always shot Portrait mode, and if it occurs, always have this banding vertically, on the short (!?) side of the Images.

Wrong. When you shoot in portrait-mode the long side of your image is vertical - so you CAN NOT have vignetting here!
Ths stripes in Robert´s image are vertical - which means they represent the LONG side of the frame!

It's typically if you use APG with images that have vignetting.

No. I don´t agree here! It sometimes occurs, yes. But not typically. That´s wha i definitely do not believe it has to do with vignetting.

Could be also dependend of the algorithmus of the blending engine in APG.

I suspect that, yes.

Perhaps, PTGui have a better solution there.

Maybe, yes.

If you read destinys post about "the best stitcher", you can see that I'm not happy with the blending engine, still not also in V3.5b2.

As is said: APG is one of the two preferable stitchers. Regarding they base on different strategies/algos i mean they are equally well usable.

best, Klaus

[lumelix]

Re: Banding

by lumelix » Thu Feb 20, 2014 2:16 pm

Hallo Klaus
Ich habe hier keine Lust, mich zu streiten, was bei mir passiert oder nicht.
Ich habe manchmal bei grossen Panoramen (>100 Bildern) genau die gleichen vertikalen Bänder (ja, ist natürlich die lange Seite im Portrait-Mode - Du verwirrst uns alle mit deinen vielen Aussagen).
Sie treten auch mit einer Optik auf, die praktisch null (0) Vignettierung aufweist und sind abhängig von der Überlappung. Zu knapp bemessene Überlappung verstärkt den Effekt noch.
Horizontales Banding habe ich bisher noch kaum gesehen. Es scheint hier ein (weiteres) Problem bei APG zu bestehen.

Geben wir hier doch Robert erst mal Gelegenheit, die vielen Anregungen auszutesten und schauen dann, was zum Ziel führt, ja ? Sonst verliert er auch noch den Überblick.