Size of RAW Photos not Observing Camera Settings if Not Full Native Resolution (XMP EXIF Data)

[AN 2x4]

I like to shoot in 3:2 (3592x3064) on my Lumix GX85 instead of the native 4:3 (4592x3448). Camera produces JPGS at 3:2. RAW photos (shot in 3:2 or 4:3) are saved at full 4608x3464 (extra 16px in either direction from the advertised native resolution).  

RAW EXIF data reflects the 3:2 or 4:3 size in crop settings under XMP. In 4:3 photos crop info is 8px in from all sides resulting in 4592x3448. In 3:2 photos crop info is 200px in from top and bottom and 8px in from left and right yielding 3592x3064 (the camera's advertised 3:2 resolution).

Develop ignores this XMP data however and 3:2 photos are processed at 4608x3464 regardless of Lens Correction setting (it know my lens and does correct for distortion). If I manually crop the pics to the 3:2 dimensions (Unconstrained 3592x3064), I have to change the lens correction scale to about 94% and slightly reposition the crop frame to make the pic come out like the camera's 3:2 JPG version of the same shot. 

So aside from not processing the XMP crop data, there seems to be something else going on with lens correction. I may have to correct the scale slightly differently with my Sigma lens but I can't remember at the moment and can't test right now. The general behavior of not processing XMP crop data happens regardless of the lens.

Lumix GX85
Lumix G Vario 12-32mm 
Affinity Photo V2.0.3
MacOS 12.6.2

Also, Mac's quicklook displays the 3:2 RAW and JPG versions of the same photo differently like Affinity. Shooting at 4:3 on the camera, makes the RAW and JPG versions display the same (there's the 16px difference when processing the RAW photos, but that's minor by comparison). 

 

[AN 2x4]

With my Sigma lens, which Affinity recognizes, I have to set the distortion to -2 and the scale to 102 (102.5 would be better) to make the image match the camera's rendered JPG. Distortion of 0 made the center of the pic bulge noticeably when toggling between the camera's JPG and Affinity's.

Lumix GX85
SIGMA 16mm F1.4 DC DN | C 017
Affinity Photo V2.0.3
MacOS 12.6.2

 

[AN 2x4]

An update on lens distortion on the first post:
In addition to making the scale 94% the distortion can be up to 5% and still not quite match the camera's JPG, but honestly, Affinity's correct lens at 94% scale and distortion 2 or 3% looks better and more correct than the Camera's JPG. 

Lumix GX85
Lumix G Vario 12-32mm 
Affinity Photo V2.0.3
MacOS 12.6.2

[MEB]

Hi @AN 2x4,
By default/design Affinity Photo uses our own RAW engine - Serif Labs - which doesn't discard any information/data the camera manufacturer considers unreliable, letting you decide where/how to crop the image thus the slightly bigger image dimensions. You can set up Affinity Photo to use Apple (Core Image RAW) instead if you wish - which does output the image size according the manufacturer specs. To do this open a RAW file, then go to menu View ▸ Assistant Manager..., change the first dropdown (RAW Engine) to Apple (Core Image RAW), close the file you have opened and load it again. You should now get the image dimensions recommended by the manufacturer.

[AN 2x4]

Got it. Sorry for not exploring it further. I am enjoying the Serif RAW engine. Would a check box to use the camera’s crop box ever be considered? If I shoot a pile of 3:2 pics, it’d be nice to check a box or have it part of a preset recall. Then, as crop is non-destructive, if I opened the crop tool I could easily slide the image around to restore some of the bounding area or redo the crop altogether. Thanks.