I know many portrait & wedding photographers love to shoot wide open at f/1.2 & f/1.4. However, with newborn photography, many of the baby poses can have extreme angles and you often will have better luck with your depth of field and sharpness by shooting around f/2 & f/2.2. Remember, it will be rare that the baby’s eyes are on the same plane of focus all the time and by closing down my aperture a bit from wide open I get that little bit extra of depth of field that is often needed.
Before you begin researching photographers, you'll need to first decide what type of photography style you prefer, as that will help determine which kind of photographer you'll want shooting your wedding. Get inspired! Spend time pouring over any kind of imagery you love, from décor shots to a fashion blogger's Instagram feed. Once you have a good collection of inspiring photographs, try to narrow in on what draws you to them specifically and dissect what feels most authentic to you and your partner. Maybe that's formal-posed portraits, a classic photography style or a lifestyle, photojournalistic feel. If you love sharp and contrast-y shots, perhaps a photographer with a flair for the dramatic is the right choice for you. Remember that you don't necessarily need to narrow in on one style in particular, since many wedding photographers can do a blend of portraiture and documentary-style shots, a mix of black-and-white and color images and so on. But if there's a special style you love, make sure to focus on photographers who specialize in it.