Question about synchronizing

[huguito]

I have few hundred pictures and a few folders that I add to my folders of photos using windows or Bridge.
When I open Ligthroom and point to the folder where my pictures live, and ask it to Synchronize, the small menu that shows it is counting shows me the right amount of pictures, in this case about 600 .
Then, after the progress bar up at the top left finished updating, it takes me to another screen, I guess is the ADD screen, where it looks like I should ask lightroom to add the new pictures.
In the directory of the folder the new files and folders are accounted for.
But in the main screen looks like Ligthroom will add to the catalog every one of the 90,000 pictures I have. it shows random thumbnails of every picture in every folder and they ALL hace a check mark on.
I am afraid that if I press the button that says ADD, I will have everything duplicated.
Is this right?

I am having such a hard time understanding the idiosyncrasies of this program

[pflower]

On the right hand side of the import screen there is a panel called File Handling.  Open that up and there is a checkbox titled "Don't Import Suspected Duplicates".  Make sure that is checked.  the thumbnails of all the photos that are already in the catalog should then be greyed out.  Try that first.

[eliedinur]

This ^^ and also don't synchronize such a high level folder. It sounds like you are synchronizing your highest photography parent folder. Synchronize the only the actual folder that you have put the photo files into. Or don't use synchronize, select File/Import Photos and Video..., navigate to the folder and Add the imports.

[huguito]

I check the option of not including duplicates and that took care of including the new files and folders only.
Only one file was not included and had to import manually

Why is it a problem just to synchronize the whole folder of pictures?
Shouldn't the software recognize on its own what's new and what's existing already?