Hello there Steffen_R.,
Thanks for stopping by the Apple Support Communities! From what you're describing, it sounds like you do not want to have your pictures synced through iCloud. Furthermore, you'd like to remove certain pictures from your iPhone 6 via syncing in iTunes. I know that I like to be able to manage my photos on my own terms and I'll be happy to provide you with some resources.
To begin, let's ensure that all your pictures are safely imported to your computer so you don't risk losing any important memories. The following article will walk you through that process:
Import photos and videos from your iPhone, iPad, or iPod touch
Once we know that your pictures are safe, we can begin the process of disabling the photos feature in iCloud on your devices and setting up your devices to manually sync content through iTunes. We'll start by disabling photo syncing through iCloud. This article has the steps on how to turn off iCloud Photo Library and how to remove the pictures from iCloud:
Get help with your iCloud Photo Library
Check out this section specifically:
How do I remove all iCloud Photo Library content from iCloud and my devices?
To turn off your iCloud Photo Library, follow these steps:
- On your iPhone, iPad, or iPod touch, go to Settings > iCloud > Storage > Manage Storage > iCloud Photo Library, then select Disable and Delete.
- On your Mac, go to Apple menu > System Preferences > iCloud. Click Manage, select Photo Library, then select Disable and delete.
Photos and videos will be stored in your account for 30 days. To download your photos and videos on your iOS device, go to Settings > iCloud > Photos and select Download and Keep Originals. On your Mac, open Photos, choose Photos > Preferences, then select Download Originals to this Mac. You can also select the photos and videos that you want to download from iCloud.com.
You may also want to turn off the My Photo Stream feature and iCloud Photo Sharing. This can be done via the same path listed above.
Once the iCloud photo features have been disabled on both your devices, we can turn our attention to iTunes. First, let's make sure that the automatic sync feature is turned off. Without your connecting your iPhone, launch iTunes. From there, click on iTunes in the upper left corner near the Apple logo. Next, click on Preferences > Devices and make sure there is a check mark next to "Prevent iPods, iPhones, and iPads from syncing automatically".
Now that automatic syncing is turned off, we will be able to connect your iPhone and then work to remove the pictures from your device. This resource provides the steps on how to manually sync pictures to your iPhone, as well as how to remove all or some of your photos:
Keep your photos safely stored and up to date on all your devices
I'd like to highlight this section for your specifically:
Turn off iTunes syncing
If you don't want the synced photos on your iPhone, iPad, or iPod touch anymore, turn off syncing in iTunes and they'll be removed from your device. You can turn off syncing for some of your photo albums or all of them at once.
Stop syncing some albums
- Open iTunes on your computer and connect your iPhone, iPad, or iPod touch.
- Click on the device icon in iTunes.
- Click Photos.
- Choose "Selected albums" and deselect the albums or collections that you want to stop syncing.
- Click Apply.
Stop syncing all photos
- Open iTunes on your computer and connect your iPhone, iPad, or iPod touch.
- Click on the device icon in iTunes.
- Click Photos.
- Deselect "Sync Photos" then click "Remove photos."
- Click Apply.
Learn how to delete photos and videos synced from iTunes when you can't access the originals.
Take care!