Unless you go to a lab with really obsolete equipment or your photo is made with instant Polaroid (butt-ugly stuff), your photos are going to be "digital". Modern printing machines scan the film, and beyond this point there is no difference in printing process between film and digital.
All the way throug GC process I submitted digital photos. I shot and edited them by myself and then got them printed in a good lab. Never got any problems with those photos, even my US-born sun has home made photo in his passport.
By the way, newly published USCIS photo requirements explicitly endorse digital.
