delete photos

Hi I've been removing a lot of dross from my phone including some photos. So, I went through the usual procedure to delete certain photos & then later I deleted the 'recently deleted' photos folder. So far so good - none of the deleted photos could be found anywhere. Later I installed an app...

Updated my software last night on my iPhone 7 - had the software downloaded, updated before I went to bed. Noticed this morning some issues with a picture, and then went into camera roll - over three years of pictures are gone. Last picture / date is from September 2014, but also even more...

I take all my photos with iPhone and DSLR. All photos move to my iPad/Mac over iCloud synchronizing or importing (Lightning SD Card). This works very well. As a next step, i tag the best pictures as "favorites". But how to delete all the untagged "non-favorite" photos? In the iOS Photos App...

Wanted to delete old photos but no matter what I do they come back over and over and over ...and no they are not connected it iCloud......so being desperate...I export all photos to a WD external HD and then iPhoto is clear and clean of all photos.......until the next day when they all come...