Photos app compressing your pictures?

Hello everyone!

As many people around here, I recently switched from iPhoto to the new "Photos" app. I globally find it quite nice, however I can't find something: how to export photos without compressing them? Here is what happens:

- I import a JPG photo x that weights let's say 8Mb, into Photos.

- Everything looks fine, you can edit it, add it to the folder you want etc. If you right click and select "more informations" it still tells you it weights 8Mb.

- NOW comes the problem I apparently can't solve: when exporting it, (by click-and-drop or going into File > Export, it doesn't matter) it apparently compresses it; its weight is reduced by 50%-75% (our photo x would only weigh something like 3Mb after the export).

So any idea how you can export photos from the Photos app without compressing them?