Studio flash issues

[brendenward35]

Hi,

I have a small studio which I have 2 lastolite lumen 8 lights, the problem i have is no matter how low the setting is the lights are too powerful. I've tried soft boxes, umbrellas and still cannot get the light low enough in the photo's I take. Even with the camera iso set at 100 it is still quite bright.
Does anyone have any suggestions? (lens filters, put some kind of de-fusser over the lamps)
Because I'm photographing kids playing camera speed is important to capture movements in the studio.

Guidance would be very much appreciated.

Thanks
Brenden

[Manfred M]

Brendan - what power setting are you running them on? I have larger lights (640 WS; albeit a different make), and get get the lighting levels down so that I can get close and do product photography. Kids playing seems to suggest that the lights are some distance away from your subject. I tend to be within a few feet of my subjects tend to run around 1/8 or less power .

I would have expected that at the 1/32 setting the power output would be fairly low. Light modifiers are not going to reduce the lighting level that much, just redirect it and umbrellas tend to scatter light more than other modifiers.

[brendenward35]

Hi,
they are 100w bulbs which I'm told have an output of 400w light during the flash. They are about 6-8 feet away from the subject and I've turned the flash setting all the way down from full and still too bright. Do you think turning the umbrellas so the light bounces off the wall might fix the issue?

[Manfred M]

Your flash will have two separate lights; the 100W are likely the modeling lights which should either power down or have minimial effect on the actual shots. The actual flash output will be through flash tubes that produce a very short burst of bright light. I've looked up the manual on line and unfortunately, there is no information on the power output other than at 100%; where there seems to be a typo (the manual shows a rating of 400 W/s; whereas I would expect the rating to be in W-s).

You are shooting at ISO 100; I assume you are shooting on manual settings, so what shutter speed and aperture have you selected?

[brendenward35]

Hi,
I've got the camera set on the P setting for canon 50d and turned the iso down to 100 am I missing a trick here do i need to do everything manually? what settings would you recommend? appreciate your kind help

[Manfred M]

Yes; I'm pretty sure that I understand your problem now. I assume you are fairly new to using studio lights?

Your studio lights have NO integration with your camera (unlike a dedicated flash), so if you are shooting in P mode, your camera will select the shutter speed and aperture based on the output of the modeling light, meaning that when the flash fires, the exposure will have been determined by the ambient light levels and your shot come out completely overexposed.

Studio lights are shot 100% on manual mode.

You need to set your shutter speed below synch speed (this is because the synch speed is based on using a dedicated flash, and there is a bit longer delay with the more powerful studio lights). If you see any banding in your shots, then your shutter speed is still too high, so reduce it until there is no banding. This information will all be in your camera manual. Don't worry too much about the actual shutter speed, as for indoor flash, the flash itself will have such a short duration as to stop motion (somewhere around 1/1000th sec is typical), regardless of the actual shutter speed.

You also have to set your lens aperture setting manually. I would probably use f/11 or perhaps even /f16 to give you sufficient depth of field.

Finally you have to set up your exposure. I normally use a flash meter, but you can also do this by trial and error, using the histogram display on your camera. The image on the camera screen does not give you a good view of how good your exposure is.

You need to adjust flash output level. Start at the 1/32 power level take a test shot. Keep adjusting up your power setting on the flash until you get a good exposure histogram). I would start at 1/32, 1/16, and play around with intermediate settings (I see that your flashes are adjustable in 1/10 stop increments). Note these down and use these settings for your shoot.

If you have two studio lights, put one of them away and work single flash for now. Multi-flash setups are much more complex to use. In terms of a starting position of the single light; a good rule of thumb to start with is set it at about 45 degrees from your subjects shooting down at 45 degrees. Distance is dependent on the diameter / diagonal of the light modifier you are using. If you are shooting with an umbrella, start by positioning the light about twice the diameter of the umbrella away from your subjects.

If you find that you do not like the shadows from the single flash, you can add a fill light. I often use a reflector to do this, but you can add a second flash as well. The fill flash should be set to deliver at most 1/2 the light as your main (also called a key) light. I would suggest a simple white reflector will be easier to use than second light; I just use the back of a piece of coreplast project board that one of my daughters used for a school project. Aim it so it fills in any shadows, if required.

[rpcrowe]

Manfred is totally correct regarding the need to shoot on manual exposure mode when working with studio lights.

I suggest that you try this test:

1. Shutter speed somewhere around 1/125 second. I have to use 1/60 second with my older studio lights but, your manual should tell you the maximum speed that your lights will sync at.

2. Start with the power setting at about 1/4. I suggest that you stick with the detentes that are on your flash for the start, such as 1/32, 1/16, 1/4 and so on. This will allow repeatability in exposure.

3. Position your light fairly close to your subject (I assume you are bouncing your light into an umbrella. Umbrellas and softboxes provide the softest light when closest to the subject). For this initial test, I suggest that you use flat frontal lighting.

4. Shoot a series of exposures starting with wide open and ending with the smallest aperture

5. Look at the series of exposures and decide which is the best f/stop to give the exposure you like. The f/stop is the only thing controlling the exposure. Shutter speed (as long as it is within the sync capabilities of the light) should have no impact on the exposure. BTW: I like shooting in a fairly dark room so that ambient light will have less impact on my exposure.

6. I suspect that one of the exposures will be somewhere within the ballpark exposure wise. You can then extrapolate using the power control and the flash-subject distance.

7. If for some reason, all of the exposures are too dark: increase the power and if all of the exposures are too light, decrease the power. I would definitely use the power settings to adjust my exposure rather than the flash-subject distance because I like to keep my umbrella/softbox quite close to my subject.

By the way, the modeling light usually gives me enough light to work with so am not stumbling around in the dark. However, the modeling light has no impact on the exposure because it will usually momentarily go out during the flash exposure. On my White Lightning studio flashes, the modeling light will go on again as soon as the flash capacitor is charged and the unit is ready to fire again!

After determining the exposure for your main light, you can actually eyeball the fill light needed (if your modeling light is fairly accurate) from a reflector or a second flash. Photographers like to get into all types of complicated ratio systems when using multiple lights but, when you are using a continuous light source or a studio flash with an accurate modeling light (which gives you a continuous source by which to judge your lighting) you can do quite well just by eye-balling the subject's lighting.

In the Dark Ages, photographers would use a dark filter (usually a dark blue) and view the subject's lighting through the filter. If the shadows were unmanageable when viewing through the filter, a lower lighting ratio (more fill light was needed). Of course, photographers were using continuous light sources for their portraiture. However, even without the advantages of umbrellas, soft boxes and other light modifiers,and usually without exposure meters, the photographers of the past were able to do very decent work as this image of my father, shot in the early 1930's shows...



Of course, today, the double shadow on the background would be a no-no! The darn cigarette was a prop often used to make the subjects look "SOPHISICATED"

[PhotomanJohn]

I would like to add one thing that you probably understand but sometimes gets forgotten. When we say to use manual exposure we mean manually set the shutter speed, aperture and ISO. Some may forget that setting the mode dial to "M" only sets two of the three exposure controls to manual. If Auto ISO is enabled, you are still in an auto exposure mode.

I have always found studio photography a lot of fun and hope you do also. One thing that will greatly reduce the frustration level during setups is to eventually buy a flash meter as Manfred mentioned.

John

[William W]

. . . Don't worry too much about the actual shutter speed, as for indoor flash, the flash itself will have such a short duration as to stop motion (somewhere around 1/1000th sec is typical), regardless of the actual shutter speed. . .

Note the Original Post:

. . . Because I'm photographing kids playing camera speed is important to capture movements in the studio. . .

Important question for Brenden to answer:

Do you mean that you want the images of the Children, the have MOTION BLUR?

WW

[inkista]

Brenden, just a couple of additional notes.

0. Get out of "P" mode, as everyone's saying. If you're NOT comfortable shooting in M and driving the exposure settings yourself, my recommendation is to put the flash gear away completely until you can shoot in M mode comfortably. IMO, ambient-only exposure is a basic skill you need to have under your belt before you add flash. If you need help with this, Bryan Peterson's Understanding Exposure is a great basic text on learning "the exposure triangle."

1. Once you've got the ambient mastered, start to think of using a flash as combining two separate exposures into a single image: the ambient light (everything that isn't from your flashes), and the flash (only the light from the flash). While they're inter-related, you can actually control both types of light independently of each other, which is the power and glory of using strobes.

The reason your camera can't set everything automagically for you with flash is that the meter can only measure the light in the scene coming through the lens. The flash burst isn't in there, yet, so it can only tell you about ambient. That's why you need to be in M--to account for what will happen when the flash burst comes into the scene.

What Manfred means by stating that the studio strobes are completely manual is that they don't have any sort of electronic communication with your 50D other than the "sync/fire" signal. If you were to use a Canon hotshoe flash on the hotshoe, or the pop-up flash on the 50D, there's additional communication going on where the camera can use metering to automatically set the flash power. This is called TTL (or eTTL-II for the specific version Canon dSLRs use). Here, the camera tells the flash to throw out a "preflash" of a known brightness, meters it Through The Lens (TTL), compares what it gets against the known value, and adjusts the flash power before the main flash burst.*

Studio strobes can't do TTL in this way, which is why you have to set up the flash's power manually, as well as adjust the exposure settings for the addition of the light from the flash in the scene. Often, those adjustments may not be within the exposure compensation range, which is the main reason why M is the favored shooting mode for studio flash setups [shot-to-shot consistency and precision of control being others].

ambient controls: iso, aperture, shutter speed.
flash controls: iso, aperture, power setting, flash-to-subject distance.

2. The 50D's max. sync speed, btw, is 1/250s.

3. When Manfred mentions the power on the flash, what he's talking about is the setting on the dial on the back of the flash head. The one on the lower right, labelled "22" on page 4 of the manual [click on the thumbnail to see a larger version].

Capture.jpg

The power settings are ratios of the full power of the strobe: 1, 1/2, 1/4, 1/8, 1/16, and 1/32. You can think of these settings as "stops", just as doubling/halving your iso or shutter speed are also stops.
_______
* In Canon cameras, with eTTL-II and auto shooting modes, the shooting mode you're in affects the behavior of the pop-up or a hotshoe flash. Being in Av/Tv mode by default sets the camera to assume you only want the flash for fill (i.e., most of the light will be from ambient, a little bit from flash), so you can get a very long shutter speeds in Av even with a flash attached and the image, if shot in low light, can look very underexposed. P, however, only assumes fill in higher levels of light, and switches to flash as the main source of illumination in lower levels of light. You can get Av to behave like P when it comes to flash by adjusting your custom settings, and setting the shutter speed to default to your max. sync speed (1/250s). Just assuming you may have defaulted to P for flash because of this behavior without knowing why it "worked" while Av "didn't work."