My last two rolls of Fuji Reala came back from the lab and the processor said they had a noticable blue shift. Anyone know what might have caused this? To my untrained eye they seemed to scan fine... both rolls were shot with a Canon T-90 and various lenses.
It's hard to tell without seeing them. The usual cause is that the pictures were taken in open shade, where the light is much more blue. Backlit scenes sometimes have the same problem. With some films, underexposure can make pictures look blue as well as dark. Altitude is also a common cause. Things are more blue above 5000 feet, but since you seem to be in Iowa, I doubt if that is the problem.
Norm makes good points about lighting, but you also need to check on your lab's processing. Did you happen to have exposed an 18% grey card, or better yet a grey card and MacBeth color checker chart on the same roll? If you make a practice of including at least one such frame then you can pick out processing problems more readily. Good labs should run control strips and not have such problems, but even good labs sometimes make mistakes.
which doesn't make them immune. If the film's spec is changed, which happens often, the film's original channel on automated equipment, or filtration requirements change as well.