lens for a group shot question

mrcoons · August 3, 2008

I have to photograph a large group this week. It is a band that is around 120 members. I've told the director I want to shoot this in the gym on the bleachers. I'll end up with around 11 or 12 rows with the maximum in one row of 15. (Will stagger the members so no one is behind anyone. They will be in all black uniforms, also. No hats.)

The gym has pretty good light but I plan on using 2 or 3 flashes on stands (probably with umbrellas) for fill light.

My question is lens selection for my 40D. My first choice is the Canon EF-S 17-55 f/2.8 and I have rented a Tokina AF 11-16mm f/2.8 (that should be here tomorrow). I always fall back to my trusty 24-105 f/4L lens too.

Anyone have a comment on which lens they think will work best?

Arkayem · August 3, 2008

mrcoons wrote:

I have to photograph a large group this week. It is a band that is around 120 members. I've told the director I want to shoot this in the gym on the bleachers. I'll end up with around 11 or 12 rows with the maximum in one row of 15. (Will stagger the members so no one is behind anyone. They will be in all black uniforms, also. No hats.)

The gym has pretty good light but I plan on using 2 or 3 flashes on stands (probably with umbrellas) for fill light.

My question is lens selection for my 40D. My first choice is the Canon EF-S 17-55 f/2.8 and I have rented a Tokina AF 11-16mm f/2.8 (that should be here tomorrow). I always fall back to my trusty 24-105 f/4L lens too.

Anyone have a comment on which lens they think will work best?

If you plan to use your flashes for fill, then make sure their color temperature matches the ambient, or there will be color shifts all over your image.

When I shoot really large groups, I use lots of flash and try to make the flash primary, so there will be no color shifts.

Then, I place the flashes as close to the camera as possible. If you place the flashes away from the camera, even in umbrellas, the light is not soft due to the distance, so you will get shadows and obvious light fall-off. As long as the flashes are close to the camera, the light fall-off will not be as noticeable.

I also place the rows as close to each other as possible to minimize the light fall-off from front to back and depth of field required.

See my blog on this subject.

ziggy53 · August 3, 2008

mrcoons wrote:

...

The gym has pretty good light but I plan on using 2 or 3 flashes on stands (probably with umbrellas) for fill light.

My question is lens selection for my 40D. My first choice is the Canon EF-S 17-55 f/2.8 and I have rented a Tokina AF 11-16mm f/2.8 (that should be here tomorrow). I always fall back to my trusty 24-105 f/4L lens too.

Anyone have a comment on which lens they think will work best?

If the gym is large enough (if you can back up far enough), I should think that the Canon EF-S 17-55mm, f/2.8 IS USM would work well. Try to use as long a focal length as possible to moderate the effects of perspective distortion. (If you shoot from the floor of the gym, the heads in the back row would be smaller than the heads in the front row unless the camera and lens are a ridiculous distance away.)

Think of the heads of the subjects as forming a flat plane, roughly the same plane as the bleachers themselves. It would be nice to have the camera and lens lifted to such a height that all of the heads are roughly the same distance to the lens, or roughly place the camera perpendicular to the subjects' collective plane (which would also be roughly perpendicular to the bleachers.) It doesn't have to be absolutely perpendicular to the palne of people, but the closer you get, the better the separation between heads as well. There is probably a balance of height that you will find satisfactory.

Likewise, it would be nice to have the lighting above the camera but evenly distributed across the subjects' collective plane. If you can't physically position the lights to this point, you might be able to achieve this through bouncing off the ceiling of the gym. (Using ceiling bounce you probably wouldn't need umbrellas.) If you have a flash (incident) light meter you can use it to check for evenness of light, even without subjects. Studio lights really are indicated for a group this size.

I would not recommend using the gymnasium lights as they are usually pretty terrible for color quality. If you can test this beforehand it would be best. (At a local junior college where two of my kids graduated, the color shift was so dramatic for one student that I had to use the "Channel Mixer" control in PhotoShop to try to get her flesh tones even close.)

mrcoons · August 3, 2008

ziggy53 wrote:

If the gym is large enough (if you can back up far enough), I should think that the Canon EF-S 17-55mm, f/2.8 IS USM would work well. Try to use as long a focal length as possible to moderate the effects of perspective distortion. (If you shoot from the floor of the gym, the heads in the back row would be smaller than the heads in the front row unless the camera and lens are a ridiculous distance away.)

Think of the heads of the subjects as forming a flat plane, roughly the same plane as the bleachers themselves. It would be nice to have the camera and lens lifted to such a height that all of the heads are roughly the same distance to the lens, or roughly place the camera perpendicular to the subjects' collective plane (which would also be roughly perpendicular to the bleachers.) It doesn't have to be absolutely perpendicular to the palne of people, but the closer you get, the better the separation between heads as well. There is probably a balance of height that you will find satisfactory.

Likewise, it would be nice to have the lighting above the camera but evenly distributed across the subjects' collective plane. If you can't physically position the lights to this point, you might be able to achieve this through bouncing off the ceiling of the gym. (Using ceiling bounce you probably wouldn't need umbrellas.) If you have a flash (incident) light meter you can use it to check for evenness of light, even without subjects. Studio lights really are indicated for a group this size.

I would not recommend using the gymnasium lights as they are usually pretty terrible for color quality. If you can test this beforehand it would be best. (At a local junior college where two of my kids graduated, the color shift was so dramatic for one student that I had to use the "Channel Mixer" control in PhotoShop to try to get her flesh tones even close.)

ziggy,

I had thought about shooting from a ladder to get up to the middle of the group.

Using the flash (do not have studio lights so that is all I can try) I figured I'd have to use a custom white balance. I'll have to review the site this week to decide if bouncing is an option. With the size group and distance to the subject from the camera would direct flash be bad? Shouldn't be close enough to wash anything out, just provide some fill?

ziggy53 · August 3, 2008

mrcoons wrote:

...

Using the flash (do not have studio lights so that is all I can try) I figured I'd have to use a custom white balance. I'll have to review the site this week to decide if bouncing is an option. With the size group and distance to the subject from the camera would direct flash be bad? Shouldn't be close enough to wash anything out, just provide some fill?

If you can visit the site before the actual shoot, take a large white target and shoot some RAW images including the white target and some flesh tones. Then shoot some samples of the target with your flash.

Later, using a suitable RAW converter, determine the color balance of the gym lights and determine the color balance of the flash. If there is a tremendous disparity, you might need/want to filter the flash.

Once you get your flash balanced fairly close to the gym light you are right that you can just dial the output of the flash down to a fill ratio amount and it should not be that necessary to bounce or diffuse the light. (With speedlights you may not be able to afford the loss in power from diffusion or bounce.)

All of this assumes that you can use the gym lighting as primary. Do you have any experience with this gymnasium and its lights?

mrcoons · August 4, 2008

ziggy53 wrote:

Do you have any experience with this gymnasium and its lights?

No, not really. I have shot in there a couple of times but not recently. Generally only time I'm in there is just in passing, as with this shot:

As I recall this was pretty much straight out of the camera.

Scott_Quier · August 4, 2008

Arkayem wrote:

Then, I place the flashes as close to the camera as possible. If you place the flashes away from the camera, even in umbrellas, the light is not soft due to the distance, so you will get shadows and obvious light fall-off. As long as the flashes are close to the camera, the light fall-off will not be as noticeable.

With respect, this statement is not quite spot on.

Placing the lights sources close to the camera, especially at the subject-to-camera distances we are talking about here my increase the incidence of red-eye. Can you see it in the print? Don't know - what size print are you talking about? Getting the flashes of the camera-to-subject axis will reduce the incidence of red-eye.

Light fall-off is a function of the light to subject distance. Taking, for example, the situation described by the OP, if the light(s) were placed at the opposite end of the gym such that the distance from the light to the first row is a significant fraction (approaching 90%) of the distance between the light and the last row and (further assume) the power/duration of the flash adjusted to "properly" expose the first row. Given this, the light reaching the last row would be something in the neighborhood of 82% (assuming I’ve done the math right) of that at the front row. Remembering that a 1-stop falloff would equate to 50% - this light falloff is nearly insignificant and should be easy to correct in post.

Take the same scenario, but position the light such that the distance to the last row is 2X the distance to the first row. Now, the light falloff from the first row to the last row is actually 2 stops. Not so easy (maybe impossible

) to correct in post.

The strength of the shadow boundaries (how "soft" is the light) is not a function of the subject-to-light distance so much as it's a function of the apparent size of the light source as viewed from the perspective of the subject. Bouncing light off a wall/ceiling produces "soft" light because the light source isn't the flash that's being used. Rather, it's the size of the reflected spot of light on the wall/ceiling. Shoot-through umbrellas, softboxes, and diffusion panels work because they greatly multiply the surface area of the device (the light source) seen by the subject.

Photoskipper · August 4, 2008

for group photos, a close to standard lens focal lenght is better in order to avoid distortion at both end of the group. The 40D is 1.6X and need a focal lenght around 30 mm.
for the lights source, it is very tricky. You may want to check what is majority color of the clothings. The in-camera light meter may be fooled by the clothes color.

Multiple flash with big reflector is perfect but not easy to set up unless you have the professional crew and contractor stand by for you and the venue owner allow you to do it a day before.

120 people is not a very big group and they may line up for 4 -6 rows and up to 15 meter wide, It creates more challenge to the light source and the depth of focus. Just to be careful with the light intensity between the front row and the last row. High mount reflector and flash may be needed.

The ceiling spot light from the stadium roof creates a lot of shadows and the color temperature is a bit too cool.

Test shot to finalize the exposure, position of lights and reflectors then bracket it.

Discuss with the host how to arrange the group position and get couple of helpers to guide the group into position will make the job faster and you can still see the smile on the faces.

The last thing you need is the luck.

Arkayem · August 4, 2008

Scott_Quier wrote:

With respect, this statement is not quite spot on.

Placing the lights sources close to the camera, especially at the subject-to-camera distances we are talking about here my increase the incidence of red-eye. Can you see it in the print? Don't know - what size print are you talking about? Getting the flashes of the camera-to-subject axis will reduce the incidence of red-eye.

You won't get red-eye as long as the lights are not directly on the axis of the camera. I normally place them well above and as close to the camera as possible. This makes all the shadows fall behind the subjects from the perspective of the camera, so you can't see them in the image. If you position a light way off to one side, then shadows from people in front will fall on other people behind them and you can see that. Also, the people closer to that end of the group will be brighter.

The higher I can position the umbrellas above the group, the better.

You can also minimize shadows by using multiple evenly matched lights spaced appropriately across the group. However, if you try that with small flashes in umbrellas, they are far from evenly matched and you almost always get shadows and uneven lighting.

It also helps to use a diffuser like a Gary Fong Light Sphere II on the camera as the Commander to the remotes, and set it to fill shadows. However, this will sometimes cause red-eye if you are too far away, so you have to be careful. If I use on-camera fill, I always use a fairly wide focal length as well. That keeps you closer and minimizes red-eye. But then you have to watch out for perspective distortion, so you can't win, so you always go for the best compromise.

Light fall-off is a function of the light to subject distance. Taking, for example, the situation described by the OP, if the light(s) were placed at the opposite end of the gym such that the distance from the light to the first row is a significant fraction (approaching 90%) of the distance between the light and the last row and (further assume) the power/duration of the flash adjusted to "properly" expose the first row. Given this, the light reaching the last row would be something in the neighborhood of 82% (assuming I’ve done the math right) of that at the front row. Remembering that a 1-stop falloff would equate to 50% - this light falloff is nearly insignificant and should be easy to correct in post.

Light fall-off is actually a function of the square of the distance. At twice the distance, you get one fourth the light. You will never get enough light from small flashes in umbrellas that far from the group.

lens for a group shot question

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