Batch Formatting

[nightowl72]

I believe this is my ignorance and not and Xn View issue, but would like to make sure.

I am batch formatting over 100 pictures to archive them. They are all about 2mb to start with. I am setting them all to 1200 pixels high by 1600 pixels wide and 300 PPI. This greatly decreases their size and will still allow for very good prints and screen size.

My issue is this. I assumed since the resolution was the same on all of them, they would all be about the same file size. I assumed wrong (that happens a lot when it comes to this). Their file sizes range form 520kb to 160kb. I am concerned by the wide range of file sizes.

Is it the compression? I noticed that some (but not all) of the pictures with a lot of the same color in the same area (for example, water) have smaller file sizes.

It took me a lot to figure out for myself how all of this stuff works, and I don't want to screw it up now.

Thank you in advance for your time.

Shawn