WINDOWS 10 Photo ProgramIn Windows 10 photo viewer, with the photo open select the settings . . . then select RESIZE (3rd down). In resize you can save as option C define custom Demensions. Select 1200 for width which should set height to 900 automatically, Check MAINTAIN Aspect Ration, and with the quality slider select a value between 40-80%.
The sweet spot is about 80-120KB for a 1200 by 900 image from my camera is at 75% quality . It will take some experimenting, but once you find it, it's the same every time.
With the Windows Photo Viewer, you can import from the camera, and then open and save each picture to a new location. Those pictures are then uploaded.
After you upload the photos, you can delete them from your computer. Next time you post, save the new pictures into the same folder.
I just took a picture of the dog as an example.
40% is a size of 70KB
60 percent is 99KB
80 percent is 129 KB
You can use the arrow in the viewer to move between those pictures. No difference I can see.
NOTE that all these pictures are physically the same size. It's just the number of pixels per inch that is different.
BATCH RESIZING I use a program that is no longer availible to do this. I've been doing it for my eBay listings for 22 years so I don't even give it a thought.
I wrote a book on eBay and did a chapter on editing with free programs. XNview is the program that seemed easiest to use then.
Here's the chapter:
https://train99.com/images/ar_ebayimages.pdfThe program looks more robust than what I wrote about back then. Might be a little different than I wrote. Here's the program download page:
https://www.xnview.com/en/