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Jurgen

raw image luminosity calculation still inaccurate with Affinity Photo

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Hello,

 

I noticed with the previous release of Affinity photo an extremely low level of luminosity values in raw files and I reported it here - as for Release 1.6.7 it was announced that raw processing had been reviewed I was hoping that the situation had improved but it hasn't.
Attached are 2 screenshots, one from Affinity photo and a second from another raw processing application. The exposure reading of the camera for this photo was -0.7, I purposely underexposed slightly. As you can see all automatic application of s-curves etc was switched off in both applications. The other app reads the exposure value correctly whereas Affinity Photo still displays a histogram that is underexposed by several stops. This is not an academic issue, in order to make that image publishable I would need to boost exposure by a large number of stops which would introduce a lot of noise which when using the other raw processing app would not be necessary.
It would be great if you can look into this seriously. I do not think that the issue is with my camera (Sony A7 R II). I love your application a lot so I want to use it for the entire process and not develop raw files in a different app and then reload the tif images into Affinity Photo for further correction.

clean histo Affinity.jpg

clean histo other.jpg

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Oops it took me more than 2 minutes to write so I didn't see yours :-) Now the Affinity guys have 2 reasons to take this seriously.
Did you post histogram shots as well? They need to see...

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4 hours ago, GabrielM said:

Hi @Jurgen ,

 

Can you please attach the raw file so we can have a look?

 

Thanks,

Gabe. 


Hi Gabe,

 

sure, this is raw file directly from my camera's SD  card, a large file of course.

I hope this helps!

Best wishes.

A7_04530.ARW

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Thank you for your explanations, it makes sense. However how does this explain the appearance of noise when adjusting the luminosity? Explanations put aside, the display and handling of a raw file by Affinity Photo is _objectively_ erratic, as I said, I exposed at -0.7 stops. The reading in Affinity Photo and the resulting necessary corrections are based on a photo underexposed by (I estimate) 5-6 stops.

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1 hour ago, owenr said:


DxO is doing tonal processing that's similar to what a camera does when set to produce a JPEG, and it possibly cannot be disabled by the user.

You have disabled the auto tone curve of AP Develop, so a flat image is presented. If you enable the auto tone curve, then you'll get a result more similar to that of DxO

Both apps allow you to modify an additional tone curve.

 

Screenshots of AP and RawTherapee, both with no exposure adjustment, tone curve or noise reduction:

 

5ac8b760e127c_APflat.thumb.png.0a99e60a0f5d0eb3b564361bbc7fada4.png

5ac8b7b0406c1_RTflat.thumb.png.fd4688a18ae519310efccd9424313913.png

 

 

Now with a +3.0 exposure in both apps to better reveal the noise:

 

5ac8b83b303f8_AP3noise.thumb.png.e214aa6028a6be54e4214a3ab72f6f40.png

5ac8b89f6f3f7_RT3noise.thumb.png.f928b89e1b2631349110c332f0b726df.png

You can disable all corrections in DXO as I have done several experiments in both AP and DXO with identical RAW files and AP is still at least 1 to 3 stops darker than DXO. Exposure values should be displayed correctly out of camera regardless of which software is used.

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8 hours ago, Gregory St. Laurent said:

You can disable all corrections in DXO as I have done several experiments in both AP and DXO with identical RAW files and AP is still at least 1 to 3 stops darker than DXO. 

At least in the screenshot you provided, DxO Smart Lighting is applied, using the "Slight" preset. In effect, this will adaptively change the exposure in different parts of the photo.


Affinity Photo 1.7.1, Affinity Designer 1.7.1, Affinity Publisher 1.7.1; macOS High Sierra 10.13.6 iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM
Affinity Photo 1.7.1.143 & Affinity Designer 1.7.1.1 for iPad; 6th Generation iPad 32 GB; Apple Pencil; iOS 12.3.1

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10 hours ago, R C-R said:

At least in the screenshot you provided, DxO Smart Lighting is applied, using the "Slight" preset. In effect, this will adaptively change the exposure in different parts of the photo.

 

Wow smart lighting is NOT on - that's why I copy-pasted the entire corrections. 

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25 minutes ago, Jurgen said:

Wow smart lighting is NOT on - that's why I copy-pasted the entire corrections. 

This is what your screenshot shows for that:

5ac9ec642bd61_smartlighting.png.89ca5d5b62b5007676595b7adf3ca39f.png 

It appears to be on & set to the "Slight" mode (intensity set to 25).

 

EDIT: Also, I believe you will see more settings if you scroll down -- note that there is a scroll bar on the right indicating only about half of the settings are visible in the window.


Affinity Photo 1.7.1, Affinity Designer 1.7.1, Affinity Publisher 1.7.1; macOS High Sierra 10.13.6 iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM
Affinity Photo 1.7.1.143 & Affinity Designer 1.7.1.1 for iPad; 6th Generation iPad 32 GB; Apple Pencil; iOS 12.3.1

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5 minutes ago, owenr said:

R C-R must have missed the little switch being off. His eyes ain't what they used to be :D

Where is that little switch? Even if I open the screenshot to full size in another browser tab & zoom in I still can't see a switch. :(


Affinity Photo 1.7.1, Affinity Designer 1.7.1, Affinity Publisher 1.7.1; macOS High Sierra 10.13.6 iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM
Affinity Photo 1.7.1.143 & Affinity Designer 1.7.1.1 for iPad; 6th Generation iPad 32 GB; Apple Pencil; iOS 12.3.1

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@owenr Thanks for showing me where the switches are -- on my screen, unless a switch is on the little rectangles are almost exactly the same color as the background & thus just about invisible. It is a lot like much of the Affinity dark mode UI, where there is so little contrast with the surrounding background that it is very difficult to tell if an item is selected or not (& part of the reason they added the light UI mode).

 

I really don't understand why so many graphics app UI designers think this is a good design practice. I get that the UI elements should be neutral so they don't interfere with the perception of the colors of the document, but that does not mean they have to be low contrast. >:(


Affinity Photo 1.7.1, Affinity Designer 1.7.1, Affinity Publisher 1.7.1; macOS High Sierra 10.13.6 iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM
Affinity Photo 1.7.1.143 & Affinity Designer 1.7.1.1 for iPad; 6th Generation iPad 32 GB; Apple Pencil; iOS 12.3.1

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13 minutes ago, owenr said:

I prefer a dark UI for graphics apps, and some work better than others. I have the UI Gamma control at max in the Affinity apps' preferences, so try fiddling with that if you haven't already.

I have tried adjusting the UI gamma, but even with it at max it is often still harder to tell at a glance which item is selected than I think it needs to be. Part of that is because my eyes are old; part is because the UI elements are relatively small on my 27" iMac screen; & part of it is because I often work late at night with the screen brightness turned down. 


Affinity Photo 1.7.1, Affinity Designer 1.7.1, Affinity Publisher 1.7.1; macOS High Sierra 10.13.6 iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM
Affinity Photo 1.7.1.143 & Affinity Designer 1.7.1.1 for iPad; 6th Generation iPad 32 GB; Apple Pencil; iOS 12.3.1

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7 hours ago, owenr said:

 

You can disable the corrections but these are additional to the initial automatic toning which you are not disabling.

 

Under settings you can disable any adjustments (even automatic toning as you call it) on load

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Thank you very much - I will do en-disable settings as you say and look at the results.

 

Thanks again for your time and effort!

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