Yet another group lighting question...

I am seeking advice for modifiers in a group lighting scenario. So, what am I trying to do... I am often asked to take group portraits (3-20 people) at my church. I have been using a couple of YN-460 II's in 43" umbrellas on LP604 stands (pretty typical strobist setup). I've tried convertibles with the black back on and soft silver from Westcott. The problem is that the wall and altar area behind them becomes a dark cave. I've tried adding in ambient, but the ambient quality isn't very good in my opinion.

I've picked up a few new toys that have been on my wishlist for a while (2x White Lightning x1600's, Manfrotto 1004bac/12' stands, Sekonic L-358, etc.) to help with this. My inclination is to use the lights up high and back far enough to give as little fall-off as possible. There are steps about 10/15' from the altar/wall that I use for arranging the groups.

The question that I have is in modifiers. I am leaning towards 86" PLM's in soft silver (with diffusion covers that I could use as needed). Are there better choices for what I am trying to accomplish? My preference would be to stay in roughly the $100-200 price range, portability is a bonus as is quick setup and breakdown since the shots are usually taken between church services. Feedback is appreciated...

Interested also as to what the lighting pros recommend.

Feel free to chime in people...

If the ambient isnt working, you can either move your lights back and turn them up so that the light reaches the area behind your subjects (you may want to get larger modifiers at that point), light the background separately, or find another location to shoot the images.

Thanks for the reply Shane. Do you think that the 86" PLM's are the way to go for larger modifiers? They would be double the diameter of the umbrellas that I have used so far. If my geometry is not failing me, I should be able to double the flash-to-subject distance with them and have the same apparent size. Does the difference between soft silver, white, and extreme silver with/without diffusion socks make much of a difference at 20'? 30'? 40'?. My strobes are about 4 stops brighter than the YN-460 II's that I've been using, so I have the power to more double my current working distance, but I am concerned that my light will start getting hard.

The other option would be to set up a silk between two light stands, but I fear that would take more time than I normally have to work with. Am I overthinking this?

lazer-jock wrote in post #14788105
Thanks for the reply Shane. Do you think that the 86" PLM's are the way to go for larger modifiers? They would be double the diameter of the umbrellas that I have used so far. If my geometry is not failing me, I should be able to double the flash-to-subject distance with them and have the same apparent size. Does the difference between soft silver, white, and extreme silver with/without diffusion socks make much of a difference at 20'? 30'? 40'?. My strobes are about 4 stops brighter than the YN-460 II's that I've been using, so I have the power to more double my current working distance, but I am concerned that my light will start getting hard.

The other option would be to set up a silk between two light stands, but I fear that would take more time than I normally have to work with. Am I overthinking this?

Yes, youre probably overthinking it. Id try 2 60 inch umbrellas. Cheap and effective.

Large source modifiers reduce the Inverse Square falloff to almost Inverse Linear, within a distance of about 2-3x the largest dimension of the modifier. So one of two means of reducing the 'black cave background' effect is to use a larger modifier. For example, if your modifier is 5.6' from the subject and the background is 5.6' further behind the subject, Inverse Square falloff would cause the background to be -2EV darker (quite darker) than the subject, while Inverse Linear would have it only about -1EV darker than the subject.

The other way to deal with the background is to separately light it with additional light sources.

Awesome information on the light falloff Wilt. Would the diffusion sock the PCB offers for his PLM's change the light falloff with distance?

As for lighting the background, I should have enough speedlights to get it even. I would just have to see if I had enough power (I'm guessing that I do).

Shane, I've cosidered 60" softlighters for portable portraits because of the strobe and speedlight versatility. However, I might stick with PLM's for consistency of color shift in materials in the 64" and 86" modifier.

lazer-jock wrote in post #14802735
Awesome information on the light falloff Wilt. Would the diffusion sock the PCB offers for his PLM's change the light falloff with distance?

The back surface of the umbrella is what makes it 'large', the front surface does nothing to the apparent size, it only affects the perceived eveness of illumination across the full area.

Just an update... I have a shoot in the church coming up next weekend, so I pulled everything out to play today. What I finally ended up using was 2x 86" soft silver PLM's with white diffusion covers on White Lightning x1600's. Fully extended Manfrotto 1004BAC (12') stands were side by side and over 30' back from where the subjects will be. I had even illumination (f/5.6 at full power) across the span of the largest group I imagine having to shoot, and only a 1-stop falloff as you went back another 7-8 feet to the altar. The cave effect is now gone!

I dialed my power down 3 stops to use my 85/1.8 @ f/2.0, so I could pull the lights back farther if I wanted, but I would run out of space before I ran out of power. The 1-stop of falloff gives a nice look to the shots for subject separation. I also appreciate knowing that I could get away with a single strobe (loss of 1 stop) further back (loss of about 1 stop). The light would be harder (grandparents may not appreciate that...), but I could get away with it if I needed to use the other strobe as a rim light.

BTW, I didn't like the specularity of the PLM's without the front diffusion covers for the type of family shots that I will be doing. The falloff into the distance, as Wilt stated, was just the same with and without. Just my opinion, but I thought that I would throw that in in case this thread comes up in a search by someone looking for information.

How may rows deep is your group? and how far back do you need to be to shoot a group at 85mm?

at a distance of 30ft (which I assume is not wide enough) you only have a depth of field of 3'3 ft, certainly not enough if they are more than two rows deep.

My suggestion is to crank the WL's, stop down to at least f8 and if you need more ambient, slow your shutter down to 1/80 at the slowest.

First off, you'll want to get the lights clustered together as much as practical and above the camera. Crank the lights up full blast and leave them there. Adjust the ISO setting up so you can get light levels adequate for an f/11 aperture setting.

Unless the group will be on a tiered stage (each row higher than the one in front), you'll want to get the camera atop a sturdy six-foot or eight-foot stepladder. The lights still should be a couple of feet above the camera, which suggests you'll want sturdy 13-foot light stands.

I've gone through several different ideas before proving that this combination truly works. For large groups (I've done up to 80 people or so in a group), I typically use 6 lights with large umbrellas (5-footers) clustered above the camera.

DO NOT put one light left of the camera and another right of the camera, especially if the lights are at camera height. This produces some absolutely horrible shadows of heads that inevitably wind up on other people's faces.

J_O_S_H_U_A wrote in post #15154388
How may rows deep is your group? and how far back do you need to be to shoot a group at 85mm?

at a distance of 30ft (which I assume is not wide enough) you only have a depth of field of 3'3 ft, certainly not enough if they are more than two rows deep.

My suggestion is to crank the WL's, stop down to at least f8 and if you need more ambient, slow your shutter down to 1/80 at the slowest.

Two rows deep max in the groups, and I want to blur out the altar area. The background would be distracting if I shot at anything slower than f/2.8. I did play with this while shooting with my 15-85 as I was setting things up, but I kept having my eye drawn to all the shiny brass and other things in the background. So, I need to throw it out of focus.

Ambient is a mix of colors, and I am killing it in these shots. If the sunlight coming through the stained glass becomes a problem, I'll throw on a CPL (almost 2 stops of loss) and use some of the headroom I have on the strobe power. [Umbridge voice]I will have order![/Umbridge voice]

SkipD wrote in post #15154428
First off, you'll want to get the lights clustered together as much as practical and above the camera. Crank the lights up full blast and leave them there. Adjust the ISO setting up so you can get light levels adequate for an f/11 aperture setting.

Done as mentioned earlier, the stands were right next to each other and 12' high. They were basically touching to give a roughly 6'x12' bank of light. However, as mentioned above, I do not feel that shooting at f/11 will work for this venue. We want it to be clear that it was at the church, but the background would be WAY too distracting with the dof that I would get from f/11.

SkipD wrote in post #15154428
Unless the group will be on a tiered stage (each row higher than the one in front), you'll want to get the camera atop a sturdy six-foot or eight-foot stepladder. The lights still should be a couple of feet above the camera, which suggests you'll want sturdy 13-foot light stands.

I've gone through several different ideas before proving that this combination truly works. For large groups (I've done up to 80 people or so in a group), I typically use 6 lights with large umbrellas (5-footers) clustered above the camera.

DO NOT put one light left of the camera and another right of the camera, especially if the lights are at camera height. This produces some absolutely horrible shadows of heads that inevitably wind up on other people's faces.

There are two very wide steps leading up to the chancel area, so seeing everyone won't be a problem (no ladder needed here, but it is good advice to others).