The Photo application on your iPhone allows you to zoom in to it by you double tapping your screen. And if you double tap it once more you are zoomed out and if you pinch the screen to zoom further, the photo snaps back to its zoomed size. But it doesn’t zoom in further there by making it so that there is just one scale that can be zoomed into any photo. But with all that it’s a shame when considering how much details the iPhone’s camera, most especially the new models, can capture. There is a little bug in iOS that allows you momentarily zoom into any photos pasts the original zoom level and right down to one pixel. It will reset itself anytime you return to the photos. Here is how it works.
Open the picture you would like to zoom in on and click the Edit button at right top. When inside edit mode, you will have some row of buttons at the bottom which includes buttons for rotating the image, add filters, and managing the colors. Click the rotate image icon and rotate the image just once and click “Done” and save it like that. Don’t get worried about losing the image because you can always revert it back from the Photos app. A cropped picture can easily be restored and this is just by a simple rotation function. Now pinch and zoom to zoom to your desired interest.
After you return to the Photos application then open the same image you edited, it can’t allow you to zoom in the same level like before. You can only zoom to the default level. To be able to zoom in again, you will have to rotate the image once more.