Been in a long exposure mood lately, and this subject tonight has been on the "to-do" list for the longest time. I first tried it probably 7 years ago while in Yellowstone, but didn't understand the concept fully, didn't have the equipment, and/or didn't have the know how to figure out a work around. All changed now. I still don't have the equipment I'd like to pull this off (remote shutter release) - but I do know now I can still do it another way.
Simple how-to - I set the camera to take a series of 30 second shots - this is made easier by connecting it to the computer and letting it take a 30 second picture- wait a second and then take another one - rinse and repeat. Take roughly 30 of these and you have what is an equivalent of 3 - five minute pictures. Take these 30 images and blend them in photoshop so you can capture that star trail. Voila easy as pie. Thanks