Many iPhone users including iPhone 5s/6s/7 and iPhone 8 users are complaining about an issue in iPhone that while trying to transfer photos to laptop or PC they can't transfer all photos from iPhone to pc as iPhone not showing all photos on computer. It is not like that all photos are not visible in PC but there are many random photos that are missing from iPhone when accessed in Computer. For some users this is happening for thousands of photos and user is unable to transfer photos to PC.
The problem looks serious when huge number of photos are lying in your iPhone and wanted to transfer all my photos to computer and you can't import photos from iPhone to mac/PC as they are not visible. And this is frustrating “Why I can't see all my photos in the DCIM folder of iPhone?”
The issue is generally reported by users who are using iCloud library. iCloud Photo Library can be very confusing even for people who intentionally use it to store photos. Generally, all the photos are on camera roll, and none are showing up under DCMI folder. If you have iCloud turned on, but the pictures will still be shown in camera roll.
How to fix not all iPhone photos showing up on computer
Fix 1: Download from iCloud library
The issue is usually countered when your photos are stored in iCloud and the photos which are successfully uploaded to iCloud are not shown in the photos list when accessed in PC. You can download those images first and then should be able to transfer those pics successfully.
1: First turn on the iCloud Photo Library, from the settings application. Head to the app on your iPhone, scroll the list to find iCloud and opt for Photos. Swipe the iCloud Photo Library to the right to activate the service.
2: On the same iCloud setting, you will be able to find "Download and keep original" option. Turn on the same. Now you should be connected to fast good internet connection as all photos will be downloaded to your iPhone.
3: After some time open Photos application on your iPhone to view the photos available in the iCloud Photo Library app as it will synchronize the data automatically. Now you should be able to transfer these photos to your PC.
Fix 2: Use Airdrop for MAC PC transfer
This is also a solution to fix the issue when you are not able to transfer some photos to your computer as they are not visible in DCIM folder. First make sure phone and Mac in the same WIFI, Select all pictures you want to transfer, AirDrop them to your Mac.