Jimmy T Loc: Virginia

Very Important Clarification, my flash has a 200 GN (Guide Number = Subject Distance From Flash × f-stop")
https://www.digital-slr-guide.com/flash-guide-number.html

Manglesphoto Loc: 70 miles south of St.Louis

Dim Flash Loc: Canton, Michigan

I taking photos in a large banquet room with high ceilings and I don't want the flat look of a head on flash.

Dim Flash Loc: Canton, Michigan

I am taking photos of a family reunion in a large banquet room with high dark ceilings and I don't want the flat look of a head on flash.

Bridges Loc: Memphis, Charleston SC, now Nazareth PA

I also like the light bender. I will at times roll it into a circle and use it like a snoot. If you are photographing birds from about 50 ft. away, it will concentrate the light beam to be effective from that distance.

Bridges Loc: Memphis, Charleston SC, now Nazareth PA

To note: If you don't want to have your subjects look like they are pasted to a black background, use a shutter speed of around 1/15th of a sec. This should give some detail to the background so it gives a more 3-D look to the shot. The flash will freeze any motion so you don't need a high shutter speed. If there is a considerable amount of ambient light you could go up to 1/25 of a sec. but it really doesn't matter, as I said before, the flash is what will freeze the action. How many people and how many rows do you estimate? If there will be three or more rows, I would suggest a two-step ladder. Look down from just above the group and slightly tilt the camera lens to mirror the slant of the rows. This will keep the most people in focus.

flyboy61 Loc: The Great American Desert

Those work very well!
What I used for years and still do, was a cut-off end from a WHITE, no texture from the vertical blind trash barrel. (Home Depot) 5-6 inches long. Round off the sharp corners, get some sticky-back Velcro spots. Easier to remove than a continuous strip. Use what you have. 3 0n the reflector/diffuser. Wrap the flash head with a layer of Gaffer tape, and put the other side spots on it . Makes it easier to remove the Velcro when /if it needs replacing. Cheap, works well, too.

flyboy61 Loc: The Great American Desert

One layer of a white handkerchief = about 1 stop, 2 layers = 2. Some tweaking may be necessary.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

Just call me Mr. Flash Modofier! OK- just kidding!- but I have been using these devices, improvised, homemade, and pre-manufactured since 1957 with flashbulbs, strobes, studio flash gear- with everything except flash powder in a flint-activated T- Gun. I employed everything from toilet paper to the late and popular brands. The good news is, that they all work if you know the effect you want and IF YOU KNOW HOW TO USE THEM to that end.!

You also need to determine the effect you want to achieve and plan your modifier usage accordingly. There is a bit of science- no advanced physics- just the angle of incidents, the inverse square law, and the theory of diffusion of light.

To determine which modifier is best for you, you first need to determine what you feel is wrong or undesirable about straight-on, on the camera flash. Especially with small Speedlights, the light emitted is rather harsh. That is because it is a small source generated by a small linear flash tube, and it is effective power boosted by a highly polished or mirror-like reflector slightly diffused by a small plastic "lens" or diffused over the flash tube compartment. Not great for portraits. Perched atop the camera, it does no provide much modeling- classic FLATlighting- OK for fill but no big shakes for portraits.

If you have experienced a lot of on-the-camera direct flash work with the aforementioned gear configuration, you will have become an expert in the effects or effects of the inverse square law which is the fall off of light with distance. In a typical room, you will get a properly exposed subject, an overexposed foreground, and a (black-hole) underexposed unnaturally dark background. Not good!

Enter bounce light- been around forever. Indirect lighting. So, the flashes are aimed up the ceiling, either straight up or and an angle, and are reflected over a much larger area which difuses the light and spreads it over a larger area. A wall can be used in certain situations for different effects. These methods are kinda time-honored and they work to a certain degree- or NOT. The method fails or is not applicable if the wall or ceiling is not reflective, very far from the light source, and the surface is not in close proximity to the subject. This method can somewhat defeat the black hole effect. The onboard modifiers become popular because they give the photographer a portable bounce surface or diffuse regardless of surroundings and can provide more control.

If you're in your flash unit and its modifier is still on the camera, the light may be softer but still lack modeling- that will depend on the type of modifier and how you apply it.

If you scan these various forums, folks have all kinds of love/hate opinions about popular pre-manufactured modifiers. They buy, for example, a Fong dome-like model, slap in on the Speedlight, and complain that it is ineffective. Al, it does prove a more omnidirectional light source but does not necessarily provide better portrait-studio-like modeling. If your modifier or bounce technique throws most of the light upward toward the ceiling, chances are you will get "raccoon eyes" in your subjects- they will look tired and lack sparkle and catchlights. The big flappy scoop-like ones work well in certain conditions. The angle of incidence trick is to try and determine where the beam light for your Speedligh lands on the modifier and where it bounces off to where it ends up on and beyond the subject. Using the whole rig off-camera might change the effect more to your liking. One tack you can take is to fashion a few of these scoop-lie flaps out of white paper or aluminum foils and experiment. When you, find a configuration you like, purchase a high-quality one that will fit you Speedligh easily and securely.

I am not against improvised modifiers, especially if you are working in a fixed space and you are not running around with a Rube Golberg contraption hanging off your camera. A poorly crafted read-made mode can fall off at the most inopportune times if you cover events etc. I might enjoy your "professional image" if you are noticed at an event running around with toilet paper or a birth-control device attached to your camera.

There is tons of good stuff on the market. Rosco makes all kinds of diffusion material and reflective foils. I've heard good reports about Mag-Mod, and Fong Lightsphere, and I have several Rogue Flash Benders.

ABJanes Loc: Jersey Boy now Virginia

https://www.amazon.com/Greggs-Better-Bounce-Card-Diffuser/dp/B006JI1PBU/ref=cm_cr_arp_d_product_top?ie=UTF8. Peter Gregg suggests turning the flash head.

https://neilvn.com/tangents/about/book-on-camera-flash/. A very good overview on the issues relative to the direction and quality of light.

DaveyDitzer Loc: Western PA

I have a "Mag Sphere" which comes with a magnetic attachment collar for the flash and I am very happy with the results. I can show a picture if you (OP) would like.

burkphoto Loc: High Point, NC

He means an "on-camera flash light modifier." It's a device that attempts to soften the light to reduce its harshness.

Most on-camera flashes have tiny flash tubes and tiny reflectors. They put out an extremely specular light source, which bounces off shiny subjects and comes right back into the lens as tiny, mirror-like reflections. Most rounded parts of 3D subjects are, therefore, not lit well.

The goal varies, but generally, the idea is to soften and spread the light, wrapping it around 3D subjects to add texture and dimension and form. This also reduces contrast and improves color subtlety.

The hard part is that the larger the light modifier, the more unwieldy it becomes.

Spirit Vision Photography Loc: Behind a Camera.

Sage advice. Especially about dragging the shutter. Just don't drag it too much, or you will get ghosting from the ambient light.

gvarner Loc: Central Oregon Coast

I second the motion for the Lite Genius. TTL flash, camera in Manual mode, SS 1/200, F4.5, ISO 400. Can’t go wrong with that indoors.

burkphoto Loc: High Point, NC

Been there, done that, borrowed the stuff I needed.

I generally prefer to use large, white satin umbrellas and bounce lots of light into them. How large, and how many Watt-seconds it will take, depends on the size of the group.

Most on-camera flash units are marginal beyond 15 feet. Bounce them off a white surface, or diffuse them, and they lose about half their power before the light ever gets to the subject. So you may need 400 to 2400 Watt-seconds, rather than the 40 to 60 Watt-seconds an on-camera flash typically emits.

In the school portrait market, we had several approaches for team and classroom group photography. We did use on-camera strobes in small spaces with white ceilings, for groups up to 20 people. Then, we used a white card, shaped into a scoop and Velcro'd to the back of the flash unit, and bounced about half the light forward and half off the ceiling. We would stand on a ladder and photograph down, with the flash head DIRECTLY over the lens (no side mount brackets).

But when confronted with high, dark ceilings, as in a gym or on a stage, we brought a couple of 45" Westcott white satin umbrellas, with an 800 Watt-second Norman 808 power pack driving two 400 Watt-second flash heads. We put these on ten-foot stands, and sand-bagged the stands if we were outdoors or in a dangerous place. They were right behind the photographer, directly above the camera, as close together as possible, and feathered for even illumination. Outdoors, we used a Paul Buff Vagabond inverter power supply system.

We used flash meters to set exposure and One Shot Digital Calibration Targets to verify exposure and provide a white balance reference.

Most folks are not going to have industrial strength equipment like this, which is why professional group photographers exist.