This is a recent DSLR image made in Ocean County, New Jersey. I had seen examples of long exposure photography that exhibited substantial cloud blurring but I hadn’t pulled many off before this. I still would like to increase the length of this type of shot to minimize shape definition but that will require use of Bulb Mode on the camera and even less light hitting the sensor.
Above photo was taken with the tripod mounted Canon EOS 50D camera and the Tamron SP 10-24mm Di II LD lens. A Hoya 77mm HDx400 HMC filter is screwed onto my lens thread. This 9-stop Neutral Density filter greatly lowers the amount of light that reaches the camera’s sensor. Exposure time is 30 seconds at F/10 ISO 100. Mirror Lock-Up and Camera Timer were also set on the camera to reduce loss of sharpness from vibration of the camera’s mirror or from my hand pressing the shutter button.