Yes, you may want to extend the expiration date. When you import a tape it will automatically reset its expiration date to the length of time defined by the retention level. For example. If you import a tape that had a retention level 6 and the value of that retention level is 2 weeks then its new expiration date for the imported images will become todays date + 2 weeks. If the 2 weeks is not long enough, then change the expiration to infinity and manually expire them when you are finished with the images.