Image - File Sizes versus Image Quality
This image gallery attempts to illustrate the relationship between file size and image quality. The two images were taken with a Sony RX1R and a Carl Zeiss Sonar 2/35 lens.

Images 1 to 3 in the first row all have the same pixel dimensions of 3840 width and 2880 height with a resolution of 300 pixels per inch. In contrast, the file size of the image in the first row was changed from ‘Low’ to ‘Maximum’.
This results in a file size of 595 KB for image 1 on the left (‘Low’), 1.2 MB for image 2 (“Medium”) in the middle, and 7.3 MB for image 3 (‘Maximum’) on the right.

Images 4 to 6 in the second row all have the same original pixel dimensions of 7072 width and 5304 height with a resolution of 350 pixels per inch. In contrast, the file size was changed from image 1 ‘Low’ to image 12 ‘Maximum’.
This results in a file size of 1.3 MB for image 4 on the left (‘Low’), 2.9 MB for image 5 (“Medium”) in the middle, and 24.3 MB for image 6 (‘Maximum’) on the right.

For a second comparison, a less technical image has been added alongside the ‘Old Town San Diego’ image in the first two rows. Here, too, there is no visible difference between ‘Low’ and ‘Maximum’. It is regrettable that the technigal quality is so low.

Images 7 to 9 in the third row all have the same pixel dimensions of 3840 width and 2880 height with a resolution of 300 pixels per inch. In contrast, the file size of the image in the first row was changed from ‘Low’ to ‘Maximum’.
This results in a file size of 970 KB for image 7 on the left (‘Low’), 2.3 MB for image 8 (“Medium”) in the middle, and 11.4 MB for image 9 (‘Maximum’) on the right.

Images 10 to 12 in the fourth row all have the same original pixel dimensions of 7072 width and 5304 height with a resolution of 350 pixels per inch. In contrast, the file size was changed from image 1 ‘Low’ to image 12 ‘Maximum’.
This results in a file size of 2.3 MB for image 10 on the left (‘Low’), 5.6 MB for image 11 (“Medium”) in the middle, and 34.1 MB for image 12 (‘Maximum’) on the right.

Regrettably, I have to say that the following images look almost identical, regardless of which quality setting was used. I am aware that large data transfers over the Internet should be avoided. However, I believe a website is not necessarily the largest consumer.
It is rather nice to see how much better digital photography has become compared to analogue photography (paper copies). Sadly, this improvement doesn’t really show up on the web. It would be favorable to be able to share photographs that are technically pleasing both at home and on the internet.
Unfortunately, I cannot choose how and how much my photographs are reduced in size. For a ‘Gallery Pro’ that now allows image enlargement, it would be beneficial to enable users to influence the file size of an image within a small range.

Important update
With the new version of Gallery Pro, I am now completely satisfied. It is now possible to set the image size to the original size of the uploaded images. I would like to express my gratitude to the team at Elements.