What are people's (experimentally tested if possible) views on sharpening images depending on whether they are to be viewed on retina or non-retina devices. Assuming resolution in the file is not an issue, which might lead to the higher resolution retina image lacking sharpness simply because there is not enough spatial information available, my thinking would be that the image to be viewed on non-retina devices would need more output sharpening for two reasons:
- The image is being downsized (more) and therefore loses sharpness due to the interpolation.
- The image is then essentially being magnified on the non-retina display, which could be considered analagous to either viewing a print up close or printing it on a medium where the ink diffuses a sizeable distance.
Do people agree with this assessment and if so what steps do you take to achieve the extra sharpening for the lower resolution image. E.g. before resizing? After? Or Both?