How to get rid of vignette banding on DJI Mavic Air 2 RAW DNG panos?

[Victor Lin]

I just bought PTGui and there is a lot of banding that I can't get rid of.

DJI Mavic Air 2 RAW DNGs.

Shot using the automatic panorama shooting on the DJI.

[Victor Lin]

No banding stitching RAW with Lightroom:

[Victor Lin]

No banding with In-Drone stitching on the Mavic Air 2:

[Victor Lin]

Lots of banding with PTGui. And yes, I'm using the Optimize Now vignette correction option.

[Victor Lin]

Considering that Lightroom is able to stitch the RAW DNGs with no banding, I'm thinking that this is a PTGui issue. 

Is there any way to fix this?

Original files (240MB)

https://drive.google.com/file/d/1s074LV9lCzD4vfNHlHLU-c3N3NGd7d9I/view?usp=drivesdk

[Erik Krause]

Am 30.06.22 um 10:15 schrieb Victor Lin:

> Considering that Lightroom is able to stitch the RAW DNGs with no banding,
> I'm thinking that this is a PTGui issue.

It's a raw conversion issue. PTGui uses only very basic raw conversion.
which doesn't make use of the embedded vignetting correction data. Use a
decent raw converter to convert to 16 bit TIFF (this is recommended
anyway if you want to use the full power of raw shooting). Then stitch
the resulting TIFs.

--
Erik Krause

[Kelly]

Eric is correct, it's best to not use DJI's DNG directly in PTGui, and instead use ACR, LR, etc. to first make 16-bit tiffs. Don't do anything else to the images beside removal of chromatic aberration (CA).

Top: after initial loaded DNGs; Bottom: after initial loaded TIFFs

[Victor Lin]

Thanks for the tips guys.

- Will PTGui update their RAW conversion code to include proper vignette correction? It's such a basic thing and having paid hundreds of dollars for this software, it's a big thing to not have.

- Does a 16-bit TIFF include *all* of the original dynamic range data as the RAW? The reason I shoot in RAW is to maximize dynamic range, maximize what I can pull out of the shadows and highlights, and allow myself to change white balance losslessly afterwards. I'd like to preserve all of these properties in the resulting TIFF.

[Kelly Bellis]

That's an interesting question that DNG's creators at Adobe should
authoritatively answer in absolute terms. From personal experience using
various HDR softwares over the years, I think the answer is yes.

[Erik Krause]

Am 30.06.2022 um 17:21 schrieb Victor Lin:

> - Will PTGui update their RAW conversion code to include proper vignette
> correction? It's such a basic thing and having paid hundreds of dollars for
> this software, it's a big thing to not have.

I hope PTGui will focus on image stitching, because that's it's main
purpose. Good raw conversion is an art of it's own, and maintaining
hundreds of raw file formats (and meta data options) is far beyond it's
scope.

> - Does a 16-bit TIFF include*all* of the original dynamic range data as

> the RAW? The reason I shoot in RAW is to maximize dynamic range, maximize
> what I can pull out of the shadows and highlights, and allow myself to
> change white balance losslessly afterwards. I'd like to preserve all of
> these properties in the resulting TIFF.

Yes, it does, if the conversion is done properly. Most raw converters
have a cli9pping indicator.

It might well be you get even more dynamic range using a decent raw
converter. PTGui uses libraw as a raw conversion library, which offers
only basic support. Also see: https://ptgui.com/support.html#3_7

--
Erik Krause
http://www.erik-krause.de

[PTGui Support]

> - Will PTGui update their RAW conversion code to include proper vignette
> correction? It's such a basic thing and having paid hundreds of dollars
> for this software, it's a big thing to not have.

Improved vignetting correction is on the wish list.

> - Does a 16-bit TIFF include *all* of the original dynamic range data as
> the RAW? The reason I shoot in RAW is to maximize dynamic range,
> maximize what I can pull out of the shadows and highlights, and allow
> myself to change white balance losslessly afterwards. I'd like to
> preserve all of these properties in the resulting TIFF.

A typical camera sensor offers only 8 to 10 bits of dynamic range:
https://www.photonstophotos.net/Charts/DXOPDR.htm

Raw files typically store 12 to 14 bits, of which the lower bits are
mostly noise. This is linear data. A 16 bit tiff typically is nonlinear,
with a gamma of about 2. This means that you'll have the equivalent of
32 bits of resolution in the darkest areas.

So in other words: yes, the 16 bit tiff will preserve the full dynamic
range.

If image quality is so important, you should be using a dedicated raw
converter. PTGui just offers basic raw conversion.

Joost

[Philip Chong]

Just for fun, I edit this Pano in full.  It took me 30 minutes taking my sweet time, doing digital painting. You did a good job getting the correct exposure. Usually, I mean usually, there is no need to do AEB.

https://we.tl/t-I00zXy662b

Where is this place?