Exposure/ HDR vs. Exposure Fusion/ Post Processing

[Mike Nelson Pedde]

Hi There:

I'm new to PTGui (but not to panoramas). I was making some images in th Pacific Northwest rainforest (read dark), and so even at ISO 5000 my images came out underexposed. Here's an example:

I pulled these three raw files into PTGui, aligned them, and in the Panorama Editor window I set Exposure Fusion to 1 EV, increase shadows 2 EV, decrease highlights 2EV and under Post Process I set the shape to .24. I exported the panorama and got this:

It's a little flat and PTGui has added a lot of colour noise, but Capture One and Topaz Denoise AI can sort that out.

New project, same three images. No post processing this time but I went to Exposure/ HDR and set Optimize Brightness to Enabled and left everything else. The camera response curve I left at .26 and created a new panorama. I got this:

The output file is actually darker than the original raw files?

Mike.

[PTGui Support]

Hi Mike,

You'll get the best results by developing your images to 16 bit TIFF first, and stitch those in PTGui. Jpeg also works but this has only 8 bit depth.

PTGui has basic raw development capabilities but it doesn't do noise reduction. At ISO5000 this is an issue.

I tried stitching the jpeg images you attached and the result looks fine to me. I'd be happy to look at your raw files if you could make them available for download (via google drive, wetransfer or similar).

Kind regards,

Joost Nieuwenhuijse
www.ptgui.com

[Erik Krause]

Am 09.03.23 um 03:56 schrieb Mike Nelson Pedde:

> The output file is actually darker than the original raw files?

Raw files must always be converted in order to view them. So you cannot
compare a converted version with the original raw file, but only with
another conversion (and be it the one in camera).

--
Erik Krause

[Mike Nelson Pedde]

Joost:  I've been playing with the program and find it's best to leave the exposure work for Capture One Pro. I use Topaz DeNoise AI for noise reduction. Rather than having to make .tif files of every raw file I want to link up, I create the panoramas in PTGui, export them as .tif files, open those into Capture One, do the exposure adjustments and then run them through Topaz Denoise. Using Topaz as an external editor in Capture One creates as secondary .tif file in Capture One and this becomes the denoised image, which I subject to further processing. I was wondering if there was any benefit to doing exposure adjustment in PTGui before exporting the panorama, but there doesn't seem to be. I chronicled some of my adventures here if you're interested: https://www.wolfnowl.com/2023/03/low-light-high-noise-and-iso-invariance/

Mike.

P.S. The Sony a7Riii claims to be (mostly) ISO invariant between ISO 640 and ISO 51200 but I need to do more experimentation on that. The trade-off of course is lower DR at higher ISOs but the question I want to answer for myself is whether it's better to underexpose at a lower ISO or to push the ISO in order to get a more balanced histogram. I can only answer that for (one) Sony a7Riii camera. Those with different sensors would need to run their own experiments. Working in the rainforest means that it's never very bright so these are real world choices for me.

Thanks,

Mike.

P.S. Kolor Autopano was my preferred stitching software for years (until DxO bought the company and closed it). I've tried several others along the way. I recently purchased PTGui (and more recently upgraded to PTGui Pro) and am liking it very much.

[Carla Meeske]

FYI I use a similar method, but I run the RAW files through DXO Pure Raw as step one, before doing anything else, then make sure they have a similar exposure in ACR, then create TIFF and  stitch in PTGui. Back to ACR for toning and the beginning of the processing.

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[PTGui Support]

Hi Mike,

Yes this is to be expected. Your ISO 51200 images are very noisy, and
PTGui's raw converter doesn't remove that noise. So if you increase
exposure, the noise will become more apparent and you can no longer
remove it. PTGui doesn't add noise though (as you claim), the noise was
already there.

Kind regards,

Joost Nieuwenhuijse
www.ptgui.com

> www.ptgui.com <http://www.ptgui.com>

>
> On Thursday, March 9, 2023 at 9:10:48 AM UTC+1 wolf...@gmail.com wrote:
>
> Hi There:
>
> I'm new to PTGui (but not to panoramas). I was making some
> images in th Pacific Northwest rainforest (read dark), and so
> even at ISO 5000 my images came out underexposed. Here's an

> example:DSC20404.jpg
> DSC20406.jpg

> DSC20408.jpg
> I pulled these three raw files into PTGui, aligned them, and in
> the Panorama Editor window I set Exposure Fusion to 1 EV,
> increase shadows 2 EV, decrease highlights 2EV and under Post
> Process I set the shape to .24. I exported the panorama and got
> this:

> DSC20408 PTGui Pro Panorama.jpg
> It's a little flat and PTGui has added a lot of colour noise,
> but Capture One and Topaz Denoise AI can sort that out.
>
> New project, same three images. No post processing this time but
> I went to Exposure/ HDR and set Optimize Brightness to Enabled
> and left everything else. The camera response curve I left at
> .26 and created a new panorama. I got this:
>

> DSC20408 PTGui Pro 2 Panorama.jpg
>
> The output file is actually darker than the original raw files?
>
> Mike.
>

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