I write a very simply script (in bash) to generate the good URL to download files DSC*$i*.JPG with $i from $NUMDEBUT to $NUMFIN. I think such a function could be useful, when you know you have the function in the owncloud android app to auto-upload the camera picture tooked with your smartphone.
The script is here if it can helps (in french but the script is clear) : http://sdubois.evolix.net/blog/2016/03/15/sauvegarder-ses-photos-de-smartphone-avec-owncloud-puis-recuperation-dun-groupe-de-photo-a-posteriori/