Still struggling this time with banding in the image [Archive] - Nodal Ninja Forum

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sanfairyanne
10-06-2011, 02:45 PM
It's embarrassing that I hold the last two posts on the forum, am I the only one who can't work out my pano's.http://www.nodalninja.com/forum/images/icons/icon9.png

I just put together a pano' I did in Athens, unlike my previous pano's this one is from a distance. I have vertical banding above the Parthenon and the building to the left. I once made the mistake of doing a pano' with a polariser attached but this has definitely not had a polariser.

Can anyone suggest why this is please.

Regards Andy

Bill Bailey
10-06-2011, 04:57 PM
It's embarrassing that I hold the last two posts on the forum, am I the only one who can't work out my pano's.http://www.nodalninja.com/forum/images/icons/icon9.png

I just put together a pano' I did in Athens, unlike my previous pano's this one is from a distance. I have vertical banding above the Parthenon and the building to the left. I once made the mistake of doing a pano' with a polariser attached but this has definitely not had a polariser.

Can anyone suggest why this is please.

Regards Andy

great pano! Can you tell us what your camera settings are for "each" image (ISO, shutter, aperture and white balance settings) . Or at the very least the two side images that create the banding. Most likely your camera had other than manual settings. Also what stitching software do you use?
Bill

nick fan
10-06-2011, 08:32 PM
how many images are there? how many rows? banding can be caused by uncorrected vignetting of lens.

Nick

nick fan
10-06-2011, 08:32 PM
how many images are there? how many rows? banding can be caused by uncorrected vignetting of lens.

Nick

John Houghton
10-06-2011, 11:07 PM
The two dark areas are in the vicinity of the two brightest features in the scene. This suggests you didn't use a fixed shutter speed/aperture/white balance for all the shots, or possibly you shot RAW images and used AUTO exposure/white balance settings in the conversion to TIFF/JPEG. If you didn't shoot RAW, I suggest you adjust the brightness of the affected images before stitching, or if you are using PTGui Pro you can interactively adjust the exposure offset parameters of the images on the Image Parameters tab whilst viewing the unblended version of the panorama in the Panorama Editor window (so the seams are made more obvious).

John

sanfairyanne
10-08-2011, 02:29 AM
Bill Nick and John,


Thank you for your replies and sorry for not getting back to my own post immediately. I have just checked the exif data and the images were shot using a 70-300 DO Canon lens. I have never used this lens before for pano's but had to on this vacation because my 24-105 L lens developed a fault.

I have realised one thing I omitted to mention in my post. It was quite breezy up on the hill from where I took this shot, with the camera set up with the NN5 the lens was blowing around quite a bit. I took this pano' without even using the NN5, I must have put it on the tripod and just swung the camera on the ball head. So pretty embarrassing that I'm requesting help from this forum when in actual fact I didn't use the NN5 for this shot. As I say it was solely because of the wind.
Incidentally I have processed a pano' taken much later in the trip that did use the NN5 and the DO lens combination and that is fine.

It was shot on RAW at 100 iso.
Aperture was f8 throughout.
There were 4 images in the pano'.
White balance was set to auto.
All 4 were shot at 1.3 seconds.
Just one row of 4 images show horizontally.

Thanks again

nick fan
10-08-2011, 06:35 AM
you shot raw, so you can develop all images with same setting with custom WB. Did you observe/ correct the vignetting of lens? what software are you using?

NIck

sanfairyanne
10-08-2011, 09:28 AM
Nick I shot in Ptgui.

I am a little unsure what you mean by asking if I corrected for vignetting of the lens. I have Lightroom 3, there is a section in the Develop module where you can enable profile corrections

I didn't use this, I just loaded the images into Ptgui and that's what I got.
I'm going to play around some more with the pano' I can try CS5 photomerge and custom WB.
Personally I'd junk the picture it's just an experiment.


I'll play with this and get back with my results.

John Houghton
10-08-2011, 10:52 AM
I just loaded the images into Ptgui and that's what I got.

If you loaded the RAW images into PTGui, then the camera settings will apply. Since you used auto white balance, you really should do a conversion from RAW to TIFF (or even JPEG) so that you can set the same specific white balance for all the images instead of using the auto setting. That's the best way of getting the images to blend easily.

John

sanfairyanne
10-08-2011, 11:15 AM
I processed the pano' again the results are attached and this time have success. I believe I may have mistakenly asked Lightroom to export the images as Jpegs and then processed Jpegs in Ptgui.

This time around they were definitely RAW files, one is processed solely in CS5 the other in Ptgui then CS5 just for the levels.

I kept the WB as shot.

Maybe the Greek government can use this image to sell the Parthenon on Ebay!!!


Thanks very much for all your help and consideration. I acknowledge that I should have gone over process more thoroughly in the first place.

John Houghton
10-08-2011, 11:39 AM
I processed the pano' again the results are attached and this time have success. I believe I may have mistakenly asked Lightroom to export the images as Jpegs and then processed Jpegs in Ptgui.
That would not have been a mistake. The mistake is in not applying the correct settings when the RAW images were converted. Whether you do the stitching in CS5 or PTGui, you need to ensure that no auto settings are used in the RAW conversion. Banding is still visible in both panorama images, though much less in the CS5 version.

John

sanfairyanne
10-08-2011, 03:52 PM
John I did a WB correction for one image and then copied and pasted that edit to the three others. That's the first time i've ever done that, now it seems obvious, I wonder why I didn't think of it before. Anyway I am attaching a new and I believe vastly improved image.

Thanks to all who took their time to help a beginner.

nick fan
10-08-2011, 08:32 PM
Nick I shot in Ptgui.

I am a little unsure what you mean by asking if I corrected for vignetting of the lens. I have Lightroom 3, there is a section in the Develop module where you can enable profile corrections

I didn't use this, I just loaded the images into Ptgui and that's what I got.


Lens may have vignetting and CA, use the profile correction if your lens in in the database. It should give better result. I am not sure if Ptgui respects the .xmp from Adobe Raw converter. If not your should export images in jpg or tif from LR and feed them to ptgui.

Nick

John Houghton
10-08-2011, 11:27 PM
I am not sure if Ptgui respects the .xmp from Adobe Raw converter.Nick
Nick, PTGui uses DCRaw to perform the RAW conversion and that does not respect the .xmp data, which means any adjustments made in ACR are lost.

John

sanfairyanne
10-09-2011, 03:00 AM
Nick and John,

Thanks you once again, the Canon 70-300 DO lens is in fact in the Lightroom profile correction database so I can correct for vignetting and Chromatic aberration.

I hear what you say John about processing the images as Tiff's in PtGui, it would be ok for this image with just 4 files but on occasion I've shot HDR pano's with many more images.
I wonder under those circumstances if it would be advisable to do this:

Do a WB correction synced to all the images in the Pano'.
Sync the lens profile for vignetting and CA.
Reduce the images in size and covert to Jpeg.

If the files are reduced in size I could then do a test process in PtGui much quicker than if I tried it as a Tiff. If I like the final Jpeg pano' I can process in Tiff.

Does this sound like a true statement ?

John Houghton
10-09-2011, 07:38 AM
Certainly there's no reason why you shouldn't do a test stitch with reduced size jpegs. If successful, you could apply the test project file as a template to the full size tiff images to initialize the project.

John