Just a heads up for those using Aperture:
When I create a JPG Export Preset that Sizes to Fit within for example 1200 x 1200 pixels, I have found that the resulting file has square pattern artefacts but only if I set the preset to 300dpi rather than 72dpi.
I have 2 otherwise identical Export Presets (one 72 and other 300 dpi) and they give different results. At first I thought it was JPG artefacts, but the same thing happens with PNG exports if I change the dpi setting. I am starting with an original RAW file that is 6048 x 4032 pixels.
I checked the exported file in Safari, Preview and GraphicConverter and the same artefacts are there at 100% view.
I always thought that dpi was only a label and didn't affect the file, but clearly somehow it does.
Has anyone else noticed this odd effect?
Example 300dpi export file showing the pattern effect in the detail (for example the wall):
Same file but at 72dpi export is OK