I'm starting a new project soon that will involve shooting interiors with Portra 400 sheet film and flash. Prints will be RA4. I checked the color temperature of my flash and found that it varies from about 4400K to 4800K depending on the output. The meter suggests using an 82A or 82B cooling filter to balance the flash light. The specs for portra 400 suggest no filtration for daylight or flash. I'm wondering if 4400K to 4800K is close enough to the 5500K this film is presumably calibratred for? Is it impotant to filter in this case? Thanks in advance for your advice...