It's great to scan a group photo based on the size you want to print it. Again, printing same size as original--scan at 300dpi; twice the size--scan at 600dpi, etc. However, be sure you take into account it just might contain the only image of a relative you don't readily recognize. If the photo is on loan to you, and you have to return it after scanning, think through your options. A good overall scan plus some detailed scans of individuals really won't take long at all, and may well give you images that prove integral to your family's pictorial history later on. This photo ended up providing us with a couple's only photo from that time in their lives. It also yielded the only picture we have of two sisters together.
