You can use the free EOS app to sync to your Canon camera via wifi and you won’t have to buy a separate bulb timer! The app is really easy to use and seems reasonably stable. It’s also very handy for remote shooting when your camera is low to the ground on a tripod, especially in wet and muddy conditions. Here’s a shot taken last night using the app on a bulb setting of just over a minute. Processed in Lightroom and shot on Canon 6d & 17-40mm with Manfrotto tripod.