Rick, did you scan these pics? They were obviously taken with a quality 35mm or larger format camera, and if you can scan the negatives, it would be easier to blow up the photos. Using a flash at night means using very high speed film, ASA 400 or better. Very dense quality film designed for larger prints without losing resolution.
Any good scanner can reverse a negative to a positive image, so you can scan the negative at a higher resolution for enlargments than just scanning a print and trying to blow it up. Then you will run into pixalation problems. JMO.
I oftened wondered how the drivers felt about those flash bulbs going off when they were launching. That takes real concentration on the tree!
