Soft jpeg exports

[johnsane]

Hi!

I’m new here and I’m pretty sure my question has been asked many times before. Maybe I did something wrong when I used the search bar but I couldn’t find anything about it so please accept my apologies if there are already tons of topics about this and please post a link to where I can find the export discussions.  

   My issue: my jpeg exports are much softer then the raw file in Affinity. I use an iPad Pro 2021 12.9”. When I export an image and compare it to the image in the Affinity app there’s a big difference in sharpness. I think my export settings are in order but I’m new both to iPad photo editing and Affinity Photo so I might be missing something.
   You can see what I mean in the attached files. Just as a test I exported a file to its original size with just a little sharpness added. First image is a screenshot of the raw file in the app, the second is a screenshot of the exported photo and the third are my export settings. 
Are there any obvious mistakes?

[DM1]

Jpg uses compression so always some loss of sharpness. Use Tiff or PNG for lossless export.

[NotMyFault]

I 'm not convinced that the difference is cause by jpeg compression.

But it is next to impossible to rate the sharpness based on screenshots only.

First, screenshots need to be made at 100% zoom level. The rendering in the preview app might be unsharp by the chosen zoom factor.

@johnsane any chance you can upload the raw file, and the exported jpg?

 

To compare the Affinity photo file vs. the jpg, simply use "Place" to add the jpg image to the top of the layer stack. use the transform panel / alignment to position it exactly to start at x/y 0. You can compare the files by several methods:

1. cycle the layer active/hidden to visually inspect
2. change blend mode to "difference" for top layer. Identical pixels will be shown black, all differences non-black.
3. You may add a levels adjustment, with "white level" set to 10%, to amplify any differences by factor 10. Inspect again. You should only notice jpeg compression artifacts (edges on 8x8 pixel blocks, color deviation, banding). Jpeg could look even sharper based on these artifacts.