This is the official exposure guide for photographers using LEE Filters range of Stopper long exposure camera filters. It's designed to help you get the most from your Big, Little and Super Stopper filters - accurately calculating the precise exposure you require and offering a flexible timer for very long shutter speeds. Tap the menu at the top to select your Stopper: 6 Stops = Little Stopper 10 Stops = Big Stopper 15 Stops = Super Stopper Turn the left hand wheel to dial in your metered shutter speed (before you insert any filters) and read the adjusted exposure on the right hand wheel. The app converts a full range of shutter speeds in 1/3 stop increments. Use the built-in countdown timer for any exposure over 5 seconds and see in a glance how long you have left. For very long exposures you’ll also get a reminder notification plus all countdowns finish with an alarm and a timestamp. There’s also a handy User Guide and links to a variety of informative and inspirational web resources to support your Stopper photography.