PTP for photo transfer not working on my S6 edge I have a Mac (iMac, newest model with newest software) and it is impossible to access photos from camera roll of my S6 edge (128 GB) in USB PTP mode. 
In Apple Photo app it shows the device but it always says "no photos". I talked with Samsung support and they said that the only way to transfer photos is to make a full backup with Smart Switch (MTP mode). This transfers 30-40 GB of my photo data only for few new photos in a new backup folder on my Mac. So at the moment I transfer photos via Email or Dropbox - both are extremely slow and unpractical because of internet. 
I also tried another Mac and other cables. I tried a S4 as well which worked fine (just plug in cable and it automatically shows all photos). There is also an integrated file browser in Smart Switch which works but this is also not useful for photos. I also asked this question in a German Android forum and was not getting good solutions (e.g. "Airdroid" software) so far.
Since MTP works for me I guess this is a software and not a hardware problem? Any idea how to solve this?

Thanks!
You can use Android File Transfer to browse your device in MTP mode. All pictures are normally saved in Phone/Camera/DCIM/ or SDCARD/Camera/DCIM/, by date. You can drag and drop the files to your mac. It essentially works like a Finder window. This way only the files you choose are transferred and at MTP speeds instead of PTP.

As for PTP not working, I'm assuming you have PTP selected, and screen unlocked when you try to open iPhoto?