When i'm using the joomla standard media manager, images will be resized.
Sorry - you show Joomla media manager - but ask about OrdaSoft Joomla gallery
These are different components so settings from 1 not have sense for other.
Did you check our joomla gallery settings
We not resize original images - we only create Thumbnails with size - for excellent view Image Gallery on your Joomla Website. Any image resize - kill original photo, so we leave original photo exactly as client upload it
BUT if you need resize original images - You may use "Joomla media manager resize" -
1. With "Joomla media manager" create folder for your images
2. With "Joomla media manager" upload your image ti that folder
3. Create Image Gallery - with help OrdaSoft Joomla gallery - nut for image source set folder where to you upload your images (please check attachment)
This accessible only in Pro version of gallery