The text you set there, is prompted to the user when you try to access the library for the first time. If you don’t, the app will crash when you attempt to access the library.

When you need to access the pictures library remember to set NSPhotoLibraryUsageDescription on your Info plist. I created a class ImageLibraryHelper to access the library and extract EXIF metadata. Once we collect all the LensModel values of our picture we can show them on a UITableView and find out which is our favourite lens. TLDR: EXIF metadata is a dictionary associated to the pictures with various information like which lenses was used, the GPS location, shutter speed, aperture, ISO and many more.įor the sake of our project, we just need one value, called LensModel. I’ll just leave you the link about EXIF on Wikipedia. In order to find out the lens used to take a particular picture, we need to read the EXIF metadata associated with it. I created a project and you can find it on GitHub, so if you’re curios about your camera usage you can run on your iPhone and find out how many pictures you take with each lens. I do have a photo library on my Mac, but my DSLR pictures are there, while most of the pics I take on my iPhone are on my iCloud library, I only save on the Mac the most important ones. The post linked above teach you how to use exiftool, and if you have your photo library on the Mac this is a great option.īut what if you only have your library on the iPhone? Or the pictures on your Mac are not the same you have on the phone? Inspired by an episode of ATP and by this blog post by Alex Chan I decided to write a simple app to find out which lenses I use the most on my iPhone.

Image metadata extractor