EPT is for tungsten lighting.(to correct for yellow cast under tungsten light, might appear blue if used in daylight)
EPD is for daylight temperature.(Might be overly yellow if used for tungsten light)
If you don't like the photo effect from the studio , you can always ask them to re-take or adjust the color. You do not need to listen to their explaination on the effect. Most important is that you must happy with your photos coz' you are paying for it. If the studio dun do any action , don't pay them lah ;p
It could also be the developing lab. Whether it's yellow cast, tungsten lighting film or watsoever, a pro lab will correct it, unless the customer insist on NO color correction.
If you are not happy with the photos, don't accept it.
Sad to tell you this but, sometimes pro photographer won't admit their fault, they would ague that their photos were "purposely" taken that way, and insist that the photos were "ART". I say, insist on what you like. Afterall you are going to face all those photos for life, while, the photographer, would just be laughing all the way to the bank!
Did you look at their portfolio before you get their services?? If it differs a lot from the one you see, then you "may" be right to reject the pics. but then it's outdoor, the lighting on that day you see on the portfolio may not be the same when you take your outdoor shots. it's not in the studio, where every lighting can be control.
Don't think "PROS" will wanna use a "no standard" lab. you know, sometimes it's the customer who's not willing to pay for the better photographer and the better studios. so you pay peanuts, you get monkey.
EPT, when use outdoor under "daylight" condition will make the pics turn blue as it's make to correct tungsten lighting.
EPD, is a ISO 200 daylight slide film.
Usually when we use such films,we cross process then, are tour pics cross process?? if it's cross process, then they will look difference from normal pics.I have a strong feeling that they are doing cross process for you. normally when we do bridal shoots, we use film, for slides, we cross process them.