Kmgw9v Loc: Miami, Florida

The acquisition of the 35mm 1.8 DX lens is a great suggestion.
Great lens for indoor, limited lighting, group pictures.

kmpankopf Loc: Mid-Michigan; SW Pennsylvania

So true. I can't think of a reason why I would shoot a family function. First, if it is a family function I'd like to be part of it - not taking pictures. Second, no one wins. Everyone thinks YOU are a professional. Be prepared to deliver the results.

Basil_O Loc: Minneapolis, MN

I'll lend my two cents here: hire somebody else to do it and just enjoy the dinner. As others have pointed out, your lenses are not adequate for the task at hand, especially if you don't use flash. In the end, you will wind up with poor quality shots and a lot of frustrated folks (including yourself). These family moments are far to precious to spend all your time and effort focusing on taking pictures. The best gift "pops" could give is your presence and undivided attention to the moment.

CanonTom Loc: Birmingham

Sorry but does not sound promising with what you list for equipt. If nothing else think of buying or renting or borrowing a nifty fifty. Not very expensive and will give you f 1.8, which without a flash you are likely to need. You will likely need either f 1.8 or f 2.8 to get these shots if you are not using a flash. Frankly I would consider flash unless not allowed for whatever reason. Good luck!

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

Looks like your BACON is going to fry.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

I don't think that a fast lens is the answer here - large apertures have correspondingly shallow depth of field. More than likely he will end up using F5.6 or F8 just to make sure everyone at a table is in focus, and he can do that with his existing equipment. Flash and higher ISOs are his only alternatives. I would not cover such an event with anything less than a D700 or a D3S, both of which have great image quality even at ISO 6400 for both, and 12800 or higher for the D3S. So at lower ISO with flash he would be fine. But I think that his camera will be fine as long as he understands how to get his best results from his flash.

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

I really didn't mean your bacon will burn but your really asking for it with your current equipment.
Here is my helpful suggestion, use your fastest lens, the AF-S 18-70mm 1:3-4:5G. Your going to have to get higher on your ISO, shoot at no smaller than f5.6, your really going to have a shallow depth of field so use it at 18 mm to 24 mm.
IF it was me, I would use my SB800, turn the flash head up and behind you and use a black felt paper and put it around the end of your flash to make a funnel and use a elastic girls ponytail band to secure it to your flash. Using the flash this way will retain a lot of candle effect. Use manual on the camera and TTL on the flash. A base exposure might be 1/30 sec. at f8, then adjust your ISO to get the effect you want.
I WOULD STRONGLY SUGGEST YOU GO TO THE VENUE BEFORE THE EVENT AND TRY OUT THESE TECHNIQUES.
And, if there is a NEXT time, let a pro do the work.

camerapapi Loc: Miami, Fl.

In the first place, if you do not have training in wedding photography the couple should not expect much. Understand it is a very important day in the life of the couple.

I can only make comments based on the information you offered and the fact that there could be mixed lighting is a strong case in favor of using flash. The low available light is also in favor of using flash. In my case I do not use AUTO ISO.
Your lenses and I like the 18-70 f3.5-4.5 AF-S with flash could do a great job. I hope you know how to use flash to avoid those ugly shadows behind the subject and the harsh light on the faces.
When I did weddings I used more than one flash.

gvarner Loc: Central Oregon Coast

You could use flash compensation for either source to dial down the light and make it a fill light. I always use my Lite-Scoop on my SB600 for these types of shots.

Low Budget Dave

I just did a quick check of indoor lighting the other night. With a single 60 watt bulb in a 10' by 10' room, at 1/80 second and F2.2, I ended up at ISO 6400.

My camera has pretty good noise control, so as long as I don't blow the photos up past 6" by 9", they would be usable. Anything bigger, though, or with a crop, the photos look amateurish.

mwsilvers Loc: Central New Jersey

I agree. I mentioned in my earlier post that while the acquisition of a fast 35mm lens might allow him to shoot without the speedlight, I cautioned him that a fast lens, wide open, would be problematic for any group shots because of the shallow depth of field.

Frankly, based on the question he posed, and the fact he's still shooting with those kit lenses and owns no others for his terrific camera, I am concerned that he lacks the knowledge and experience to do this properly. That's why I suggested that he put his camera in P mode and use his flash as a bounce for every image. He may have enough of a struggle just to achieve good compositions if this is the first time he has tried to shoot something like this.

burkphoto Loc: High Point, NC

I really believe in site surveys! Visit the restaurant in advance, if all possible, and measure the light where you will be working, at the time of day you will be working. Restaurants are notoriously dimly lit places.

Meter a cheap Delta-1 gray card:

( https://www.bhphotovideo.com/c/product/15633-REG/Delta_22010_Gray_Card_8x10_2.html )

...or use a hand-held incident meter, if you have one. That will give you an idea of the aperture, ISO sensitivity, and shutter speed combination you will need, so you can formulate a strategy that works.

Remember that to avoid camera shake in hand-held images, you will need a shutter speed close to, or shorter than, 1/(longest focal length * 1.5). The 1.5 multiplier in the denominator is the "crop factor" of a DX camera. So for a 70mm focal length, 1/(70 * 1.5) or the next faster speed, 1/125. If you are less than a rock-steady photographer, use a tripod or an even faster hand-held speed.

Your kit lenses are really quite a bit slow for available light photography. If you can borrow a prime lens with a maximum aperture between f/1.2 and f/2.8, you'll be MUCH happier with the results. A 24-70mm f/2.8 zoom or a 28-75mm f/2.8 zoom would be okay, too.

Under VERY few circumstances do you need an aperture smaller than f/8 with a DX or APS-C camera. Smaller apertures give you extreme depth of field, but add diffraction to the scene, which is like using a soft-focus filter. In a situation such as this, I'd probably be working at f/2.8 to f/4!

Your camera should be okay out to around ISO 3200, before you notice distracting noise and color degradation. But I'd try to keep it at 1600 or slower. 200 to 800 is a very clean ISO range on that camera.

Good luck! Testing in advance will make your job MUCH more likely to yield good results.

dandev Loc: Enumclaw, WA

I just shot a large charity fundraiser - black room, high ceilings, yellow (very dim) lighting, no windows.
Used a Canon 5D3 with 24 to 105 - f5.6, 125, ISO 4,000. (Set to manual) And - a Canon 600 Speedlight (which was essential) with Gary Fong modifier. Ceiling was too high to bounce - and it was black. Speedlight was set to ETTL.
You need to have some depth of field - or too much will be out of focus. And you can't shoot much slower or you will get motion blur.
With all of that, I still had to do a lot of color and noise processing. (The flash and room lights were different color temps. I could have used a yellow filter (1/2 CTO) on the flash to fix that, but I forgot.)
I think you will be disappointed if you don't use a (non pop-up) flash.

Buzzardluck Loc: Tempe, AZ

FYI, I once 45 years ago acted as the photographer at my brother's wedding. Now even though they are divorced and remarried to others I still hear complaints about how bad the pictures were. As others have said hire a pro and enjoy the wedding.

BebuLamar

The best thing you can do is to visit the place and see what kind of light you have. Take some test shots and go from there.