One Light: Group Shot

Students helping me demonstrate the issues of problem with one light close the the group. Person closest is brighter than the others.
Here all I have done is repositioned everyone, but still the lady on the far left is darker than the other two in the photo.
This is the lighting setup for the two photos above

After seeing the photos above one of the first things people think they need to do is add another light. No question this would help solve our lighting problem.

Now let’s be realistic here. Most photographers starting out will have just one light and cannot justify another light until some income starts coming in. How do you solve the problem with just one light?

Inverse-Square Law

We need to first start with understanding the Inverse-Square Law of Light.

In physics, an inverse-square law is any physical law stating that a specified physical quantity or strength is inversely proportional to the square of the distance from the source of that physical quantity. (Wikipedia)

In photography it means an object that is twice the distance from a point source of light will receive a quarter of the illumination.

How this is used most often in photography is to figure your exposure.  If you want to keep the same f/stop when you move a light twice the distance from the subject then you must increase the power 4 times. Inversely if you move the light twice as close then you will need to power down the light to 1/4 the power to keep the same f/stop.

Using the Inverse-Square Law of light for Group Photo

The further you move the light from a group the difference between the light falling on the subjects faces will become less and less different. The reason is that the distance of each subject to the light source as compared to others in the group will be so small of a difference that they will appear to be more evenly lighted.

The only thing that changes from the first diagram to this one is the light source is moved further from the group and moved the light to the left side.

As you can see in the lighting diagram I have moved the light source further from the group. My suggestion is to move the light as far as you can from the group to get the most even amount of light.

You can now see that the light is more even on everyone in the photo. One person said it is light creating depth-of-field for the flash using this technique.
While this would have solved the lighting problem by keeping the lights the same in the first photo it will limit your creativity for posing with one light.  This is why moving the light back gives you more posing options and more even light in a group photo.

Technical Changes

  • ISO: You may need to use a higher ISO to have your flash still be affective. You may change from ISO 100 to as high as ISO 3200.  Remember that since you are using a flash the noise is not the same and actually can appear to disappear. (link to earlier blog on this)
  • Aperture: With group photos you will want to use f/8 or higher to be sure everyone is in focus. If you use f/2 for example your group photo above would look more like a solo act and their backup singers and not like a musical group.
  • Studio Strobe vs Hot Shoe Flash: This is when it makes more sense to own a studio flash than a hot shoe flash. You can get more power and recycle time is much quicker. (Earlier Blog Post comparing hot shoe flash and studio light)
(8+ Nikon SB900s) = (1 Alienbees 1600)
(8 x $510 = $4,080) vs ($360)

You can buy hot shoe flashes for under $90. These hot shoe flashes are not TTL, but you can use them in manual mode just as you would a studio strobe.  They are just less powerful and take a while to recycle.

This is the Vivitar 285 which you get get at B&H Photo for $87

Go and practice making a group photo and getting everyone evenly lighted using just one flash. Understanding and mastering this skill will help you when you have limited amount of equipment and still need a professional photo of a group.

How to get rid of orange and green backgrounds with flash

Nikon D4, ISO 3200, f/6.3, 1/80, 28-300mm, White Balance: Flash

Have you been getting photos like this with your off camera flash? The reason for it is you have a mixed lighting situation. The background is tungsten or 3200º Kelvin and the subject has flash or 5500º Kelvin.

Nikon D4, ISO 3200, f/6.3, 1/80, 28-300mm, White Balance: Tungsten

Now by doing everything pretty much the same except for two things are changed: the flash has an orange gel on it to match the tungsten and then the white balance for the scene is set to tungsten.

I prefer to put on the orange gel over the flash and then use my ExpoDisc to get a custom white balance by pointing the lens to the flash with the ExpoDisc in front to help me get an accurate skin tone for the subject.

Nikon SB-900 with the gel kit that comes with the flash and the two covers.  One at the bottom holds the gels and the other cover is a diffusion filter.  You can use the gels with the diffusion filter as well. There are two green and two orange filters. You can test these and depending on the lights in the room one may work better than the other.
The gel slides into the plastic cover and the hole lines up with a raised piece in the cover. When you do the the little white squares will automatically adjust your camera to the correct white balance when on the camera hotshoe.
Here you can see the cover snapped back on the SB-900 with the other gels off to the side in the carrying case.

I prefer not seeing the orange and green backgrounds in my photos when using flash. If you do use the gels as I am showing you here, then you will fly through the post production. Many people try and remove the color shift in the background with post production, but the time it takes to convert the flash to the correct gel combination if far faster than just color correcting one image.

Now imagine shooting a wedding or an event where you may have hundreds if not thousands of images to color correct if you do not use the gels.

Nikon D4, ISO 3200, f/6.3, 1/80, 28-300mm, White Balance: Flash 

This is with regular flash under fluorescent light. There are more color differences from my experience under fluorescent lights than under tungsten.  Just because you see a fluorescent light doesn’t mean it is going to be green. Some of the lights are already daylight balanced and will give you proper color with a flash. 

Nikon D4, ISO 3200, f/6.3, 1/50, 28-300mm, White Balance: Fluorescent

Here you can see the shift to a better skin tone and background not as green, because I used a green gel over the flash.

While this may take between 2 – 5 minutes to set up properly over time you may cut your time to 2 – 3 minutes to do. It is very important you see this in your over all workflow. 2 – 5 minutes once or 2 – 5 minutes for every photo you shoot to color correct it. It is your choice. Depending on the situation you might not have time. If you had the time and didn’t do it you will be wishing you had during post.

Improve your Flash photos by not lighting everything

How do you get this result? [Figure 1]
When this is where you started? [Figure 2] Nikon D3, 85mm, f/1.4, ISO 200, 1/500 on Matrix metering.
Maybe you want the light on even less of the face like this. [Figure 3]

I started this photo shoot with figure 2. I started with a back lighted subject. Most all the light is on the background and the subject is in the shade.

This is the setup.  I used a fill flash on my Nikon P7000 to take this photo.  If you look behind the model you can see the shadow from the house and see how all the sunlight is hitting the background. Nikon SB900 on light stand with Radio Poppers PX helping be sure the signal from the Nikon SU800 is not lost outside in all the sunlight.

I suggest doing this assignment yourself and take some notes just to be sure you are remembering all your settings.  While the Nikon will capture the camera settings it doesn’t show the SB900 settings in the embedded information, only that it was used.

Shoot all these combinations and you will have 16 different photos to compare the results.  Add + series and you would have 28 total different ones to look through and compare.  
As you can see in these shots the background is consistent through each series and the skin tone gets brighter and darker due to the flash changing while the Camera setting stays the same.  You then change the camera setting and re-shoot the series with the flash.

Here you can see me changing just the camera settings on the Nikon D3. The ISO stays the same. The aperture stays the same and by dialing this under the shutter speed will change automatically because I am using the exposure compensation to change it. Had I chosen to shoot this in Shutter Priority and not Aperture Priority the Aperture would change from each setting instead of the Shutter Speed.

Since the flash is off camera and I am using the Nikon SU-800 to control the flash, I am changing the SU-800 and not the SB-900.  Here is what those changes will look like.

You can continue to go through to the -1, -2, -3 respectfully to get more combinations.  The reason I am only changing A and not B or C is the Nikon SB-900 is set to Channel 1 Letter A.

Camera setting at 0 and the flash is set to -3.  Also the Flash is zoomed to 200 so I am just lighting her face and not the outfit. [Nikon D3, 85mm, f/1.4, ISO 200, 1/1000]
Camera -1, Flash 0 [Nikon D3, 85mm, f/1.4, ISO 200, 1/2000]
Camera -3, Flash +3 [Nikon D3, 85mm, f/1.4, ISO 200, 1/8000]

Now let’s back up and talk about the Zoom on the Nikon SB-900 flash.  The next three images are all shot with the Camera at 0 and the Flash at 0, but I am zooming the flash all the way as wide as it will go at 17mm to 35mm and finally at 85mm.

Zoom at 17mm [Nikon D3, 85mm, f/1.4, ISO 200, 1/1000]
Zoom 35mm [Nikon D3, 85mm, f/1.4, ISO 200, 1/800]
Zoom 85mm [Nikon D3, 85mm, f/1.4, ISO 200, 1/800]

When you push the shutter you can never see it happen, but the Nikon Speed light system fires a pre-flash to set the exposure and then fires the flash.  Now remember the camera is set to Aperture priority and the camera is in matrix metering mode trying to figure all this out for you.  When the flash was at 17mm the light from the flash is falling on the model’s black robe and the camera wants to make it darker and thus shortens the shutter speed to 1/1000.  When the flash is just hitting the face with the 35mm and the 85mm zoom setting then it is at 1/800 shutter speed.

I mention this to say when you are in TTL mode shooting in some form of auto there are variances due to each scene.  This is why you want to shoot this type of test before you shoot a real job.  Just change the model’s shirt to white and everything will change again.

Let’s mix it up a little more by adding a snoot to the SB900.

I am using the LumiQuest snoot on the Nikon SB-900.  This narrows down the light to an even smaller spotlight.
I didn’t move the flash or camera, but the model moved ever so slightly in these two examples.  This is where you can use the Depth-of-Field preview button to have the flash fire a continuous light that you can see where it is hitting the subject.  I can tell you from experience that you don’t want to do this a lot without letting the flash cool down between doing this.  I burned out the tube and had to have Nikon repair it.  Use this sparingly. [Nikon D3, 85mm, f/1.4, ISO 200, 1/5000] 

I pushed the depth-of-field preview button and then had the model stay still to get the light where I wanted it. [Nikon D3, 85mm, f/1.4, ISO 200, 1/5000] 
As you can see everything is the same as without the snoot in the setup.  By using the snoot the exposure changed a great deal even tho I am only having the Camera at -3 and the Flash at +3

Pass the Pen + Walk and Talk

Getting people doing something gives you better expressions.  I have two techniques for keeping people engaged when I have to set up a situation and then help it to become a real moment.

Pass the Pen

Many schools love to show the seminar setting for a class.  When you photograph in a room with everyone around the table Murphy’s Law states the action will be when their back are to you if you are photographing.

I have a few moments with everyone and explain my dilema.  If I shot this naturally it will take ten times longer due to I am on the wrong side of the table when someone starts to talk.  By the time I shift then the conversation has shifted.

I ask everyone to listen with their eyes and not just with their ears.  This really speeds up the number of usable images.

Typical conference table for a seminar class.

I then ask to borrow a pen and then give it to someone and tell everyone this person will talk.  I ask them to tell us what they did the other day or what they are planning to do that is exciting.  No one can interrupt them and they need to continue to talk until I say pass the pen. 

Even if you do not see the pen the person holds the attention of the group and lets me get the photos catching their various expressions.  Usually we get some laughs and good stories in the process.
Even in small groups I use the pen to help the subjects relax. 
This teacher used a similar technique for classroom discussions.  He had a ball of tape that he would toss to a student who raised their hand to answer a question. He tossed it to the student and when they were done they tossed it back to him.  He was quite impressive with his tosses and catches.
You can see as this student tosses the ball back he is engaged in the class. 

Walk and Talk

When you get people walking and talking they forget about you and engage quickly.  If it is just 2 people I have them walk close enough to feel each other bump occasionally.  I have one person talk and the other listen. I stress the importance of looking at each other and not the ground.  It is amazing when people are in a normal conversation they might look at the ground or off somewhere rather than looking at a person.  However, for a photo to communicate they are interested in each other they must have eye contact.

Again in the group situation I designate who is talking and ask everyone to give them their eye attention and not just their ears.  Off to the left my assistant is walking along with them out of camera range pointing a flash to them.  I normally use the Nikon SB900 with the Radio Poppers PX system to be sure the signal from the Nikon SU800 triggers the flash consistently.  The flash is zoomed out to about 28 setting to light the entire group.
Here you can see the tour guide helping tell the student about the campus.  Now for this photo I am using a Pocket Wizard Plus II to trigger the Alien Bees B1600 being fired off to the right of the group.  They are walking towards me as my VALS (Voice Activated Light Stand: AKA assistant) is carrying the light on a light stand and staying with the group out of the frame.
The couple is walking and talking to each other a good 50 yards from me. I like using the zoom lens so as they walk closer I just zoom out.  My VALS is carrying the Nikon SB900 with the Radio Poppers PX system being triggered by the Nikon SU800 on the camera.  I am shooting with the flash at normal setting and zoomed to 200.
The flash off camera really helps clean up the photo.  Often you will have a shadow on one or more of the people.  The other advantage of the flash winking in is it helps draw the audiences attention to the subjects.
Helping keep the dark skin tones with detail is really improved outside with the off camera flash.  I can power the flash up or down on the Nikon SU800.  Sometimes I make it +1 or -1 as compared to the exposure of the camera.  Only takes a second to look at the histogram and the LCD and see what might need adjusting.  By shooting RAW I still have lots of control in post processing, but being sure shadows have detail is really important when the dark areas can be the subjects face in a photo like this one here.
Take notice that we have details in the white shirt and the dark skin of the subjects in the photo.  This is will work in a printed piece easily.  Remember I have one person talking and the others listening with their eyes.

TTL hot shoe Flash vs Manual Studio Strobe

As your VALS is walking along with the Nikon SB900 as they vary their distance from the subject the camera still compensates being sure the power stays the same.  Of course the assistant has to remain pretty close with a hotshoe flash like the Nikon SB900 because it is not powerful enough to be much more than 10 to 15 feet away.

Now when you VALS is carrying a studio flash that means as they change the distance to the subject the exposure will change.  As they get closer the flash will get brighter and when they move away it will get darker.  However, with a studio strobe they can stay further away, since the strobes are much more powerful than a hot shoe flash.  I seldom am shooting with my Alienbees B1600 much more than 1/4 power.  I am usually at 1/8 power.  I do like to use a grid spot so I am not lighting up the ground leading up to the subjects.  I like to hit the faces and let it drop off a little.

Photographing birds at a feeder in the rain

We just love watching the birds at a feeder on our deck each day.  Of course we have to chase away some of the squirrels. 

I was wanting to shoot some photos and it was raining–then I thought let me show you how to do this in the rain.

We enjoy our bird feeder and the birds that visit us.
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By using a flash I can somewhat capture the bird in flight.  Actually I startled the bird with the flashes.
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Here is the simple setup.  I did this while it was raining and so I covered the flashes with zip lock bags to keep them dry.
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Since it was raining it was darker than normal and the flashes helped light up the birds but the background disappears.
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I decided to put one flash pointing to the background (see setup below) to help keep the background from disappearing.  However the birds had stopped for a while visiting when I was doing this.
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The Nikon SB900 flash to the far right is set on 200mm zoom.  This helps put the light on the distant trees.  The light to the right is lighting the bird feeder and any birds.