The new iOptron 3305A ball head lets you mount a digital camera weighing up to 6.6 lbs (3 kg) on the iOptron SkyTracker portable camera tracking mount for serious constellation/Milky Way star field astrophotography.
The iOptron 3305A ball head's 1.5" by 2.375" quick release plate lets you quickly mount and remove your camera and lens from the SkyTracker, yet provides a stable and secure camera platform while your SkyTracker is in operation. The quick release plate has three camera mounting bolt position options to let you balance your camera and lens more precisely. Its large aluminum alloy ball, 1.5 inches (39mm) in diameter, provides smooth movement with a very secure clamping action to prevent camera movement once you have aimed your camera. Safety stops on the ball head's quick release plate prevent your camera from accidentally slipping out of the quick release adapter.
The ball head has an integrated compass and level for easy alignment. It weighs only 14 ounces (including the quick release plate), and measures only 3.875" high. While the SkyTracker itself has a rated camera payload capacity of 6.6 lbs for imaging, the ball head will actually hold a maximum payload of 20 lbs (9.1 kg), giving you a generous extra margin of safety. The ball head housing can pan 360°, with index marks every 30°, for multi-shot panoramas. The ball head itself can tilt +/- 90°.
The iOptron 3305A ball head has a 1/4"-20 thread bolt in a quick-release plate on top for holding your camera, with a 3/8" mounting hole underneath for installing on the SkyTracker on standard tripod legs. A 1/4"-20 thread insert is provided for the 3/8" mounting hole to allow you to use the 3305A ball head on a a tripod that uses that size mounting bolt.
A review in Sky & Telescope magazine said "I've spent twice as much for ball heads that weren't nearly as good as the iOptron model, so I highly recommend you buy it if you don't already own one."