It might be helpful to rent a second camera body and flash just in case the main camera body fails. From advice here this forum I bought a Blackrapid double sling strap. One camera on each side around the side of your waist. It worked really well for me last time. If you're outside, you're F4 will be fine maybe put the F4 on one camera and the 2.8 70-200 on the other and have them both handy with the blackrapid double strap. Plus it just looks cool. I suggest rather than looking at books it's much quicker to look at Tips on YouTube for first time wedding shooters there are several really good ones. All the advice you need is on YouTube.

I do shoot raw. Although, I am not a whiz at PS yet. But I can do the basics. My contract will be verbal, and understood by many witnesses. LOL "you get what you pay for" and since I am not being paid.... I have suggested to her that she hire a professional, even if for the ceremony only, and let me take the pre wedding photos. She seems to be laid back about her decision though. So, looks like it is just me. Thanks for taking the time to offer your advice.

If we can't talk you out of it, take both bodies - one with the 70-200, and the other with the 24-105. That should cover it as long as you're outdoors and have plenty of light. Also a flash if you have it for fill (and extra batteries). Make a list of the standard wedding shots (Google) and check them off. Also, designate a relative to assemble the groups for the group shots so you can concentrate on the shots rather than herding cats. Chimp regularly and adjust as necessary. Also use the UHH search function for "weddings", and read all the advice. Still better to leave it to the pros, but if you must, good luck!

I have "never" shot a wedding before. I am a little unnerved by this thought. First let me say, this is "not" a paying job. BUT, it is a family member, who has a lot of confidence in me and happens to like my photos. She is not hiring a photographer, due to the expense. She just wants a few good photographs of the occasion, besides cell phone photos. (although, I am making sure, I have people taking plenty of those as well.) I often take family photos when we are all together, and send them to everyone. Also I post a few of my images on my FB account. My niece seems to think that I can do this, even though I have told her, I am not a professional photographer, and I still have a lot to learn. As this is not her first marriage, nor is it her fiancé's first wedding. They are not having a formal ceremony. They are getting married at their home, off the coast of Maryland. It will be outdoors, at one o'clock in the afternoon. (worst time of day for pictures lol) Hope their yard is shaded well. The dress is casual. A low country boil reception, and boating and jet skiing activities for all the guests (which is family and close friends only). Still, I want to be able to capture those special moments for her. She is more like a little sister to me than a niece. I will be ok, doing posed shots, but not so sure about the rest of it. I have the right camera for the job but not sure about the best lens to use. My best lens is my 70-200 F2.8L IS USM II for my Canon 5D Mark IV camera. Is this the best lens or is there a better one I should use. Like maybe the 24-105 F4L? also, I have a speed lite, but not any studio lighting. Even if I had it, wow, traveling with all that gear would be hard for me. So, my camera, speed light, tripod, and a couple of lenses is all I really want to take. Maybe a couple of reflectors. But that would be the most I'd travel with. So, any tips, advice, and a little compassion when giving it, haha, would be appreciated. I want feel too bad if they are not great, due to the fact that I am doing this as a favor to her. But, I am taking this as a challenge, and want to do my best.