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Image Resolution for Panorama, HDR, Stack, and Focus Merge


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I don't know if this has been covered before here but I have a question about image resolution when creating panoramas, stacks, HDR merging, and Focus merging.
Whenever I create a panorama, stack, HDR merge, or do a focus merge, the image resolution of the final image is always 96 PPI.
Why does it always produce an image with such low PPI when the original images used were 300 PPI?

I have gone through the preferences and cannot find a setting for the resolution when it comes to panorama, stack, HDR merge, and focus merge.
Is there a way to make the final image from these tasks come out with the same resolution as the original images that were used for the tasks?

Right now I have to manually change the resolution after the task is completed, which is annoying because sometimes I forget to do it and only remember after I try to upload the image to an art site and it gets rejected for low resolution.

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5 hours ago, R C-R said:

I already know about this. I know that PPI is for pixels per inch and DPI is dots per inch for printing.
My question was why does AP always make my panoramas or focus merges 96 PPI?
The camera raw images are set to 300 PPI out of the camera.
When I open individual raw photos with AP they are always what they were out of the camera at 300 PPI.
Why would AP change it to 96 PPI when merging multiple images together?

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The point is pixels (or dots) per inch (or any other physical measure of length) is relevant only for physical output, like for a printout. The camera does not output anything at 300 or any other PPI or DPI, just files that may include in the metadata nominal values that RAW converters may or may not use during development.

Likewise, when sending a file to a printer, those values may or may not be used to size the print (because prints can be scaled in various ways).

So basically, PPI/DPI doesn't matter unless/until physical output is created & resolution is defined by the number of pixels in the file.

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8 minutes ago, R C-R said:

The point is pixels (or dots) per inch (or any other physical measure of length) is relevant only for physical output, like for a printout. The camera does not output anything a/t 300 or any other PPI or DPI, just files that may include in the metadata nominal values that RAW converters may or may not use during development.

Likewise, when sending a file to a printer, those values may or may not be used to size the print (because prints can be scaled in various ways).

So basically, PPI/DPI doesn't matter unless/until physical output is created & resolution is defined by the number of pixels in the file.

I'm sure that the OP knows this. His/her problem is:

14 hours ago, DeepDesertPhoto said:

Right now I have to manually change the resolution after the task is completed, which is annoying because sometimes I forget to do it and only remember after I try to upload the image to an art site and it gets rejected for low resolution

John

Windows 11, Affinity Photo 2.4.2 Designer 2.4.2 and Publisher 2.4.2 (mainly Photo).

CPU: Intel Core i5 8500 @ 3.00GHz. RAM: 32.0GB  DDR4 @ 1063MHz, Graphics: 2047MB NVIDIA GeForce GTX 1050

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14 minutes ago, R C-R said:

The point is pixels (or dots) per inch (or any other physical measure of length) is relevant only for physical output, like for a printout. The camera does not output anything at 300 or any other PPI or DPI, just files that may include in the metadata nominal values that RAW converters may or may not use during development.

Likewise, when sending a file to a printer, those values may or may not be used to size the print (because prints can be scaled in various ways).

So basically, PPI/DPI doesn't matter unless/until physical output is created & resolution is defined by the number of pixels in the file.

I know it does not matter as far as display on the screen.
The problem is that the stock photography agencies and Print On Demand Art sites I send my images to for sale require 300 PPI.
This means that I have to manually change the 96 PPI to 300 before I can upload the image to these websites.

My question is why does AP produce a 96 PPI image when the original source images for the panorama or focus merge are already set at 300 PPI.
Why does AP not simply create the final merged image at the same PPI setting of the original source images?
It's a simple question about the way the program operates for certain tasks.

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First, I have to apologize for missing the part about the artwork being rejected. I now understand why the default is a problem for you.

However, it is still untrue that the source images themselves from the camera are set to any specific PPI (that would be in the metadata if it is included in the file), which may be why they default to the 96 value in AP. Also, at least for panoramas & I think for focus merges as well not all of the source files must have the same values in the metadata, so that also may be part of it.

Not that it is of any help for you or you can do anything about it, but any site that looks only at the metadata & not the pixel count to determine resolution is either too lazy or too clueless to do that correctly.

I guess the only thing you can do is post something to the feature request forum (where I think this already has a few comments) & hope for the best.

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6 minutes ago, R C-R said:

First, I have to apologize for missing the part about the artwork being rejected. I now understand why the default is a problem for you.

However, it is still untrue that the source images themselves from the camera are set to any specific PPI (that would be in the metadata if it is included in the file), which may be why they default to the 96 value in AP. Also, at least for panoramas & I think for focus merges as well not all of the source files must have the same values in the metadata, so that also may be part of it.

Not that it is of any help for you or you can do anything about it, but any site that looks only at the metadata & not the pixel count to determine resolution is either too lazy or too clueless to do that correctly.

I guess the only thing you can do is post something to the feature request forum (where I think this already has a few comments) & hope for the best.

I'm using a Nikon D810.
When I check the image quality settings it simple says RAW and the image area covered is set to its max (36 MP), but it does not say a specific PPI.
Yet when I open individual RAW images with AP they always open at 300 PPI. Perhaps that is the default of the Nikon PPI setting because the camera does not allow me to change the PPI.
Since individual RAW files always open with AP at 300 PPI perhaps it is because of varying metadata when I am doing sequential shots for panoramas.
When I do sequential pano shots I use Aperture Priority in which the Aperture is set to a specific F-stop but the shutter speed is left on auto.
As a result the shutter speed does vary a little from shot to shot.
Next time I will set the shutter manually so that all shots are one shutter speed and see if that has an effect on the panorama PPI created by AP.
 

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37 minutes ago, DeepDesertPhoto said:

Yet when I open individual RAW images with AP they always open at 300 PPI. Perhaps that is the default of the Nikon PPI setting because the camera does not allow me to change the PPI.

Unfortunately, I do not have a Nikon or any other camera that creates RAW files, so I have to make do with RAW files I have downloaded from the web. That may create some bias in my tests but what I can tell using those files & the EXIF Tool data that XnViewMP displays, there are 3 EXIF metadata values that can be extracted from (most?) RAW format files to derive a default value.

As labeled in the XnViewMP display (which may be converted from binary data in some way?) they are X Resolution, Y Resolution, & Resolution Unit. The first 2 are integer numbers that are the same, & the third is a linear unit of measurement, usually but not always "inches."

In most of the downloaded samples, regardless of make or model of the camera or RAW format the two resolutions are 300 & the unit is inches, but for a few of them the resolutions are 72. Developing each of them in AP results in values of 300 or 72 respectively. I have not yet found one with different X & Y resolutions but I assume that if I did those values would be used during development.

So from that quite possibly flawed logic, I think for these multi-file processes everything defaults to 96 simply so that they all start with the same consistent value, if that makes any sense.

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20 minutes ago, R C-R said:

Unfortunately, I do not have a Nikon or any other camera that creates RAW files, so I have to make do with RAW files I have downloaded from the web. That may create some bias in my tests but what I can tell using those files & the EXIF Tool data that XnViewMP displays, there are 3 EXIF metadata values that can be extracted from (most?) RAW format files to derive a default value.

As labeled in the XnViewMP display (which may be converted from binary data in some way?) they are X Resolution, Y Resolution, & Resolution Unit. The first 2 are integer numbers that are the same, & the third is a linear unit of measurement, usually but not always "inches."

In most of the downloaded samples, regardless of make or model of the camera or RAW format the two resolutions are 300 & the unit is inches, but for a few of them the resolutions are 72. Developing each of them in AP results in values of 300 or 72 respectively. I have not yet found one with different X & Y resolutions but I assume that if I did those values would be used during development.

So from that quite possibly flawed logic, I think for these multi-file processes everything defaults to 96 simply so that they all start with the same consistent value, if that makes any sense.

I usually don't delve into the metadata that deeply. Most of the time the only metadata that matters to me is the color space, date of creation, and the camera settings such as ISO, aperture, and shutter.
But like I said, next time I go out to do some landscape photography I will set the shutter manually instead of leaving it on auto and see if that has an effect on the panorama resolution when processed by AP.
If the resulting PPI is still 96 then that probably means it is an AP default and I will just have to remember to manually reset it before I upload the image to a website that requires 300 PPI.

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17 minutes ago, Aad Slingerland said:

I'll send you one... Nikon D750 RAW. And yes Nikon RAW images (.NEF extension) always show up in 300 DPI when developped.

 

dsc_2505.nef 27.12 MB · 0 downloads

I downloaded your image just to see its specifications.
It appears to be the same as my D810 except for the megapixels.
Yours is 24MP while mine is 36MP.
Yours also developed with a 300PPI resolution. Same as mine.
Like I mentioned, the problem I have is that when I merge 2 or more photos together as a panorama, a stack, or a focus merge, the finished image ends up with only 96 PPI.
As an experiment I converted the RAWs into TIFs and created a panorama from those and it still ended up with 96 PPI even though the source TIFs were 300 PPI.
So this might be some kind of AP resolution default for images created by merging 2 or more together.

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17 hours ago, DeepDesertPhoto said:

after I try to upload the image to an art site and it gets rejected for low resolution.

Usually the pixel dimensions are relevant and define the available maximum size. Do you get in Affinity a result below 6016 x 4014 px? (regardless of PPI or DPI)

If not, can you tell us what specific art site rejects your resulted images?

macOS 10.14.6 | MacBookPro Retina 15" | Eizo 27" | Affinity V1

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54 minutes ago, thomaso said:

Usually the pixel dimensions are relevant and define the available maximum size. Do you get in Affinity a result below 6016 x 4014 px? (regardless of PPI or DPI)

If not, can you tell us what specific art site rejects your resulted images?

I have accounts with many stock photo agencies and two Print on Demand websites. All of them have image requirements of 150 to 300 PPI.
Here is a blog from Society6, one of the POD sites I sell my work through.
In their blog they state that they require that the images be set to 300 DPI in order to produce the best prints.
The other sites I sell through have similar requirements.

https://blog.society6.com/prepare-art-files-printing-society6-products/

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2 hours ago, R C-R said:

In most of the downloaded samples, regardless of make or model of the camera or RAW format the two resolutions are 300 & the unit is inches, but for a few of them the resolutions are 72. Developing each of them in AP results in values of 300 or 72 respectively.

 

2 hours ago, Aad Slingerland said:

I'll send you one... Nikon D750 RAW. And yes Nikon RAW images (.NEF extension) always show up in 300 DPI when developped.

 

The Nikon is 300 dpi after processing in Photo and my Canon CR2 files are 72 dpi after processing. The dpi values are from Photo not "XnViewMP". I wind up with a couple of pictures that are 13"x20" (Nikon) and 48" x 72" (Canon).

1 hour ago, DeepDesertPhoto said:

I usually only work on one at a time.

To 300 dpi.afmacro

This works.

Mac Pro (Late 2013) Mac OS 12.7.6 
Affinity Designer 2.5.5 | Affinity Photo 2.5.5 | Affinity Publisher 2.5.5 | Beta versions as they appear.

I have never mastered color management, period, so I cannot help with that.

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I think at the moment there is no other way than change manually each image to 300 dpi. If you use macro, OP's worfklow says macro is applied "manually" to each photo.

Possibly there could be an export macro which does several operations like set dpi, apply unsharp mask, save to a specific folder. But I think export with macro had some issues...

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54 minutes ago, Old Bruce said:

The Nikon is 300 dpi after processing in Photo and my Canon CR2 files are 72 dpi after processing.

The CR2 samples I have downloaded from the web are 72. This is according to the metadata EXIF Tool shows in XnViewMP. I also have one .raf sample from a FujiFilm X-T30 camera that is 72.

When processed one at a time in AP, each of them (like all the others) sets DPI using that metadata.

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11 minutes ago, Fixx said:

But I think export with macro had some issues...

There was a problem with a Batch Job using Macros and parallel processing but I haven't seen it since the latest update. 1.8.4 on Mac.

Mac Pro (Late 2013) Mac OS 12.7.6 
Affinity Designer 2.5.5 | Affinity Photo 2.5.5 | Affinity Publisher 2.5.5 | Beta versions as they appear.

I have never mastered color management, period, so I cannot help with that.

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15 minutes ago, Fixx said:

Possibly there could be an export macro which does several operations like set dpi, apply unsharp mask, save to a specific folder. But I think export with macro had some issues...

The "issue" with AP's macro recorder is it cannot record an export step (or a save step or anything else that requires user interaction other than the few macro steps that allow limited interaction via the "Edit" gear icon).

But setting DPI via a macro is easy so it could be included in an AP batch job. Since anything developed in AP is initially in the native file format & would have to be exported to TIF, PNG, etc. anyway, a batch job might be a usable workaround, as @Old Bruce suggested.

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1 hour ago, Old Bruce said:

 

The Nikon is 300 dpi after processing in Photo and my Canon CR2 files are 72 dpi after processing. The dpi values are from Photo not "XnViewMP". I wind up with a couple of pictures that are 13"x20" (Nikon) and 48" x 72" (Canon).

To 300 dpi.afmacro 652 B · 0 downloads

This works.

I've never used one of these macros.
I tried to open it and I got an error saying that there is no program on my Mac that can open this file.
I tried to open it with AP but it would not recognize the file.

I can just manually change the resolution for the finished version before exporting it as TIFs and JPGs.

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27 minutes ago, Fixx said:

I think at the moment there is no other way than change manually each image to 300 dpi. If you use macro, OP's worfklow says macro is applied "manually" to each photo.

Possibly there could be an export macro which does several operations like set dpi, apply unsharp mask, save to a specific folder. But I think export with macro had some issues...

I can manually change the resolution. All I have to do is go to the document menu, then go to Resize Document in the menu. When the resolution window opens I simply uncheck the resample box and then change the 96 to 300. Then I just click save and that changes it from 96 to 300 PPI.
But if AP simply made the panoramas with the same PPI that the original source images were I would not have to do these extra steps.

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