Don, the 2nd son Loc: Crowded Florida

Take many shots every ingenious way you may think of, some will work.

autofocus Loc: North Central Connecticut

Lots of good advice already mentioned above, but I think Gene's suggestion of this, "Even if you are shooting at night, there is always a way to get natural looking and flattering light from a flash - even if it means you need to bring a friend to hold a large bounce surface so that the light source is large and nicely diffused, yet directional." is an excellent idea. And if you can get say a piece of white poster board, maybe at least 2 feet by 3 feet, or piece 2 together for a larger reflector it would be ideal. You also would need an assistant to hold it.
Direct flash is a very hard light, very harsh, and very unflattering. The goal is to make that small light source larger by bouncing it off a larger surface. If you can do this you might want to start with the following setup:
1) swivel the flash around so the light is aimed over your right shoulder, and have your assistant standing back there with the white poster board aimed at the flash. That person should be no further away from the flash than 3-4 feet.
2) I would shoot in full manual and start with a setting of f/5.6, and a shutter speed of !/80 -1/100. This is slow enough to pull in some ambient light (of the Christmas lights) but not too slow to create the possible problem of motion blur that still can occur when using flash with too slow a shutter setting.
3) Set flash to full power, do a quick test shot and see how the exposure looks by checking the histogram. If you think it's too overexposed you can incrementally correct that 3 ways. 1) reduce the flash power output, 2) move the poster board a little further away from the flash, or 3) close your aperture down some, maybe to f/6.3 or f/7.1. My typical choice in a situation like this would be number 3, start by closing down your aperture. But, any one of those, or a combination of those will help.
A little tidbit about using flash or lights: your shutter speed controls the amount of ambient light entering the camera, and your f/stop controls the amount of flash entering the camera. And you can start with your camera's native ISO, maybe ISO 100 on your camera, but an ISO setting of 200 should also be fine. Lastly, disregard what the meter is showing you with the settings I mentioned above and with the camera in full manual mode...it will indicate that you are grossly underexposing the shot, but the flash if used properly will provide for that.

ABJanes Loc: Jersey Boy now Virginia

I have had good luck with bounce cards when a bounce surface is not readily available https://petergregg.com/a-better-bounce-card-flash-diffuser/ You can also tape a large index card on your flash as well. Note the position of the flash head. Neil van Nierk has used this product in certain situations.

anotherview Loc: California

Flash lighting presents its own learning curve.

Before saying more, I suggest you beg off the night time assignment. Just say you do not feel comfortable with artificial lighting at night. Add that you've only begun learning this mode of shooting.

If I may so, your boss wants free photographic services using you. You must decline politely.

You have to take charge of your own photography.

Here are two Web-sits that devote to flash lighting. They should help you get your mind around this alternate mode of photography.

David Hobby
https://strobist.blogspot.com/2006/03/lighting-101.html

Neil Von Niekirk
https://neilvn.com/tangents/

Flash photography opens to many more photo opportunities. It is worth the struggle to learn and use it.

DavidM Loc: New Orleans, LA

Basically see below. Use a reflector and bounce the flash off of it for appropriate light:


Set camera to manual mode.

Manual flash
Shutter speed controls ambient light
Fstop controls flash brightness
ISO makes everything brighter or darker

Start with:
125 ss,f5.6, ISO 100
Power on flash and set to manual mode. Start with quarter power, adjust as needed.

https://www.bhphotovideo.com/c/product/1274713-REG/impact_r2542_51_42_5_in_1_collapsible_circular.html

gvarner Loc: Central Oregon Coast

This link will give you a place to start - https://improvephotography.com/50388/flash-photography-camera-settings-for-beginners/

There are many such Google links for "manual flash photography". And point the flash at a white ceiling or other large white surface whenever possible. Trial-and-error seems to be the order of the day with manual flash.

joer Loc: Colorado/Illinois

Put the on camera flash on manual and camera on manual and expose for the back round house and lights ensuring that you stay within the flash sync range with out the flash on. Then turn the flash on and start at lowest power gradually increasing the flash power until you get a pleasing shot. You can practice without the subjects for approximate setting and then dial it in with the subjects in place. Good luck and stay safe.

Bubbee Loc: Aventura, Florida

I agree with Thomas. I have the D7100 and the manual has very explicit instructors for its built-in flash and inc ludes TTL.I just
checked my manual and it's amazing! (I luckily have and use my SB800, and never used this terrific backup)
Read your book
I also think that you should try some with a high iso using flash fill
Good luck

tomcat

Etram,

You CAN do this. It's not that difficult at all. Keep these 2 things in mind: Shutter speed controls the background and flash controls the subject's faces.

1. You have to set your basic in-camera controls to manual in order to light the Christmas decorations properly so that the bulbs will be seen. Otherwise, the flash will overpower the lights and you won't see them. So I would set the shutter for 1/30 sec to start with. Set f/stop to f/5.6. Then take a shot without the flash and see if you like the results of the Christmas lights. Continue to adjust until you get a decent shot of the house and lights.

Now you are good to go for the background. The background exposure will not change when you turn the flash on, so long as you keep the camera in manual.

2. Turn on the flash to manual and adjust the output power to 1/64 or so. You only want just enough flash output to light the 3 people's faces. Adjust the flash as necessary to get proper exposure to the faces.

Again, keep in mind that there are 2 exposures in play here....the background that is set via shutter speed independently from the subjects and then the flash that controls the subjects.

Pixljockey Loc: Southeast Pa.

Hi Etram, as usual CHG CANON has great information I have used both methods he described. I also use the D7200 and the NIkon SB700 speed lite. When I took pictures of my house at night with the Christmas lights on, I actually pushed this awesome flash to its limits because I was shooting from over sixty feet away to get the whole house framed the way I wanted it. It was a dark night, no moon, and the Christmas lights were the incandescent “icicle” kind, so not of much help exposure wise. I ended up “painting” the house with the flash, that is long exposure, flash being fired three times across left, middle, and right side. Got it close to right first time, I think it was set at below full power. But flash at night is very helpful and doesn’t have to be as powerful as you think if your doing portraits. I don’t know that the “painting” method would work for you if there’s a small child (movement during longer exposure) but you never know, might want to try after you get your good shot. Just keep in mind shutter speed as it relates to ambient outdoor lights, most of which need white balance correction. I’d like to see your results, good luck!

sabfish

Thanks for the link to the article. I have used flash for years, but this is one of the best articles I have seen on the subject. I can always learn something new.

One point. The article focuses (no pun intended) almost entirely on getting effective light using bounce flash. If the requestor is taking pictures outside, she will not be able to bounce light off a ceiling or wall, but may want to try a bent white card taped or rubber-banded to the flash head to provide some indirect light.

Wasabi

Etram you have received a lot of good practical advice from the Hoggers. I can not add anything to it, but suggest you explain your in-experience to the boss, ask for their patience, show them the results of your shots as you go, and shoot a lot. You have attractive subjects and it should be a lot of fun for all. (As long as the baby behaves).

Be SURE to post the results and a quick report on how it works out.

Wasabi

OnDSnap Loc: NE New Jersey

Have a look at these sites....

https://strobist.blogspot.com/2006/03/lighting-101.html
https://members.kelbyone.com/course/skelby-one-flash/

sabfish

Thanks for the strobist link. Very useful.

gwilliams6

Number one, your exposure setting must be for the Xmas lights in front of the house, if you want them to appear with proper exposure.

Do not worry about TTL for this. Just first go over , in advance, either before the day or a bit before the scheduled shoot and take some shots of the xmas lights alone. Use manual aperture, f-stop and your flash's proper sync shutter speed. Look at the images on your rear screen and adjust until you have the xmas tree lights exposure exactly right. DO NOT CHANGE THESE MANUAL EXPOSURE SETTINGS ON YOUR CAMERA

Then be sure you can adjust the light output of your flash manually. Most flashes can have their flash output be adjusted manually . You just want to take a few tests shots with one person while adjusting the flash output power until you have the desired balance of exposure between the family and their xmas lights. That is it.

One big tip, do it around dusk as that will still give you the Xmas lights, and also give some ambient light to help fill in areas of exposure of the house that aren't lighted by the xmas lights or hit with your flash.

Most important, you are manually setting you camera to properly expose for the background xmas lights and house, and using your flash on the family to match that exposure. be sure to give yourself an f-stop that will give yourself enough depth of field to keep the entire family in focus. Do not worry about trying to keep the xmas lights in the background in sharp focus, the distance between them and the family may be too great to do that at your chosen f-stop.

This is really not too hard to pull off.