As a life celebrant and minister, I officiate at many different types of celebrations and events.  I interface with many other professionals in ensuring that the details and day run smoothly.  At weddings, baby blessings and memorials, often a videographer is brought in to record the day.  While I have worked with several terrific videographers, this past weekend I had the unfortunate experience of working with one that created problems during a wedding ceremony. 
This particular person did not use a stationary camera, nor did they wire the groom for sound.  They were moving around quite a bit during the actual ceremony, both in front of the bride and groom and behind me.  During one of the rituals I had to actually ask him to move and I noticed on more than one occasion that the photographer was having a problem taking pictures because this person stepped into their camera's view. While ultimately I do not know the quality of the product produced, my experience with this videographer prompts me to offer the following helpful questions should you wish to incorporate videography at your wedding or celebration of any kind: 

Will they contact the other professionals involved ahead of time to discuss each others needs, including your celebrant or officiant?

Will they use at least 1 stationary camera, positioned in a manner that does not distract from the ceremony or interfere with other pictures?

If this is a wedding, do they have an approach for supplementing a stationary camera that will effectively capture what they need to without causing distraction?

Will they coordinate their efforts with the photographers so that both can do their jobs? 

Will they use wireless microphones, if necessary,  in a manner that will not cause audio interruption but will pick up the ceremony?

While it is helpful during weddings and celebratory events to hire a videographer who can blend in and be inconspicuous, this becomes even more important during a memorial service. While all of this may seem obvious to a professional, it is helpful to understand how the person you ar hiring will work with you.  Let me know if their are other questions you think should be asked.