Q: iPhone 6 + Lightning to USB Camera Connection Kit problem

Welcome to Apple Support Communities, elfrommoscow!

It appears you're able to import pictures from your digital camera to your iPhone 6s but not to your iPhone 6 when they're both on the same iOS version. I'd be wondering about that as well and I'll be glad to help!

Here's the information you'll use to get it working like it should -- Import photos using Apple camera adapters -- scroll down to where it reads "If you don’t see the import option"

Have a fantastic day!

Thanks for trying those steps for us, elfrommoscow.

Since the kit an iPhone 6s work just fine, that means the issue is with your iPhone 6 specifically. The next steps will totally erase your iPhone 6 so we highly recommend backing it up first to make sure your personal data is safe. -- How to back up your iPhone, iPad, and iPod touch

After you're sure that your information has been backed up, follow this article to completely erase the iPhone and iOS installed, then put a fresh, clean copy of the latest iOS back on. -- Use iTunes on your Mac or PC to restore your iPhone, iPad, or iPod to factory settings

When you're asked what you want to use to set up your iPhone 6 again, this time through, set it up as a new iPhone. Take a few throw-away pictures from your phone then see if the Camera Connection Kit is able to communicate with it. If it does, you can use the backup you've just created to restore your personal information again. -- Restore your iPhone, iPad, or iPod touch from a backup

If your Camera Connection Kit and your iPhone 6 are still not communicating, it's time to have it evaluated. Use this link to locate the nearest Apple Store or Apple Authorized Service Provider. -- Find Locations

Cheers!