When hiring a photographer or a videographer, one thing that may be helpful for them to know is if the church or other venue allows flash photography. Although reasons may vary, this may often be due to flashes being distracting and churches want to maintain the solemness of the space.
If you find out your venue does not allow flash photography, there is no reason to be alarmed. Photographers and videographers often have special lenses that are built for low-light situations and this information can help them prepare to capture the best images for your big day. Although flash photography can help bring out details, images that are captured using natural light can be amazing as well.
Be sure to ask your photographer or videographer if they are comfortable with both flash and non-flash situations. Weddings and other special events often require flexibility and they should be ready for any situation, including power failures where a wedding has to be done completely by candlelight (it has happened!). If they are not comfortable, this could be an opportunity to find another professional.
Having your photographer/videographer can visit the venue beforehand to get an understanding of the lighting can be beneficial. If they are unable to do so, see if you can provide them with photos or even a website where they can get an idea of where the light will be coming from within the venue.
Be sure to get a good understanding of other restrictions as well. Some churches only allow photography from certain areas like balconies or behind the priest and a few may not allow photography at all. Knowing these restrictions upfront will help both you and your photographer/videographer.