Hello,

it is jpg with exif V 2.2.
I use the cache and without cache option
Here a sector from the output at recreate thumbnails.

Adding 20160702-114712-1414-snapshot.jpg to collection <picty.collectiontypes.localdir.LocalDir instance at 0x7f4f4007eea8>
loading metadata for item 20160702-052454-1397-snapshot.jpg
No usable thumbnail data for 20160702-052454-1397-snapshot.jpg
read took 0.00357580184937
Adding 20160702-052454-1397-snapshot.jpg to collection <picty.collectiontypes.localdir.LocalDir instance at 0x7f4f4007eea8>
Key 65505 Shift_L
Key 65505 Shift_L
Creating thumbnail for 20160702-000000-1392-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-000000-1392-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-000006-1392-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-000006-1392-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-000012-1392-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-000012-1392-snapshot.jpg
Opened with GDK

...

Opened with GDK
Creating thumbnail for 20160702-013936-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-013936-1394-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-013942-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-013942-1394-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-013948-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-013948-1394-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-013954-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-013954-1394-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-014000-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-014000-1394-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-014006-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-014006-1394-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-014012-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-014012-1394-snapshot.jpg
Opened with GDK
No usable thumbnail data for 20160702-000000-1392-snapshot.jpg
No usable thumbnail data for 20160702-000006-1392-snapshot.jpg
No usable thumbnail data for 20160702-000012-1392-snapshot.jpg
Creating thumbnail for 20160702-014018-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-014018-1394-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-014024-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-014024-1394-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-014030-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-014030-1394-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-014036-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-014036-1394-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-014042-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-014042-1394-snapshot.jpg
No usable thumbnail data for 20160702-000018-1392-snapshot.jpg
No usable thumbnail data for 20160702-000024-1392-snapshot.jpg
No usable thumbnail data for 20160702-000030-1392-snapshot.jpg
No usable thumbnail data for 20160702-000036-1392-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-014048-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-014048-1394-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-014054-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-014054-1394-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-014100-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-014100-1394-snapshot.jpg
Opened with GDK
Creating thumbnail for 20160702-014106-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-014106-1394-snapshot.jpg
No usable thumbnail data for 20160702-000042-1392-snapshot.jpg
Opened with GDK
No usable thumbnail data for 20160702-000048-1392-snapshot.jpg
No usable thumbnail data for 20160702-000054-1392-snapshot.jpg
No usable thumbnail data for 20160702-000100-1392-snapshot.jpg
No usable thumbnail data for 20160702-000106-1392-snapshot.jpg
Creating thumbnail for 20160702-014112-1394-snapshot.jpg /media/thomasd/backup2/Motion-Rpi2/2016/2016-07/20160702-snap/20160702-014112-1394-snapshot.jpg
Opened with GDK

regards Thomas