I'm new to flash photography

domu221

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I have a Nikon D3100 with a 35mm f1.8 that I use for taking pictures at night and in theaters. Now that I have aquired a Nikon SB700 speedlight, I'm thinking about using my 18-55mm again. When I shoot a picture with my flash and my 18-55mm, the person is brighter than the background; how can i make the luminance balancee? Also, when i use the flash, the colors loose it's saturation; which white balance should i use: flash or whatever light bulb is present in the room?
 
The brightness of the flash drops off as distance from the flash increases. It's called the "inverse square law" (you can Google the term and find some excellent explanations of how and why it does this). Basically the light is spreading out. 1" in front of your flash, pretty much ALL the photos being emitted will hit that subject. 100 feet away... and the photons have spread out over such a wide area that only a small percentage of them hit the subject.

Each time the distance increases by the square root of 2 (which we round off to simply 1.4) the light is cut in half. An easier way to think of it is each time the distance from the flash doubles then the light is cut to merely 1/4. So a subject at 10' gets some amount of light... then a subject at 14' gets half as much and a subject at 20' gets 1/4 as much (as compared to the subject at 10'.)

You can help balance the foreground & background light by "lagging the shutter". "lagging" means that you'll set a slower shutter speed. This is because when you use flash, remember that only some of the light is created by the flash, and other light was just the ambient light already availabile in the room. The flash will tend to "freeze" a subject and provide a sharp image while "lagging" the shutter (shooting with a shutter speed much slower than necessary if you only cared about the subject) will allow the camera to collect more of the ambient light for the rest of the scene.

Most flashes try to maintain a "daylight" white balance temperature -- although you may find your camera actually has a white balance setting just for flash. This only matters if you shoot JPEG.
 
The brightness of the flash drops off as distance from the flash increases. It's called the "inverse square law" (you can Google the term and find some excellent explanations of how and why it does this). Basically the light is spreading out. 1" in front of your flash, pretty much ALL the photos being emitted will hit that subject. 100 feet away... and the photons have spread out over such a wide area that only a small percentage of them hit the subject.

Each time the distance increases by the square root of 2 (which we round off to simply 1.4) the light is cut in half. An easier way to think of it is each time the distance from the flash doubles then the light is cut to merely 1/4. So a subject at 10' gets some amount of light... then a subject at 14' gets half as much and a subject at 20' gets 1/4 as much (as compared to the subject at 10'.)

You can help balance the foreground & background light by "lagging the shutter". "lagging" means that you'll set a slower shutter speed. This is because when you use flash, remember that only some of the light is created by the flash, and other light was just the ambient light already availabile in the room. The flash will tend to "freeze" a subject and provide a sharp image while "lagging" the shutter (shooting with a shutter speed much slower than necessary if you only cared about the subject) will allow the camera to collect more of the ambient light for the rest of the scene.

Most flashes try to maintain a "daylight" white balance temperature -- although you may find your camera actually has a white balance setting just for flash. This only matters if you shoot JPEG.

Tim, please refrain from scarring the New Guys with Physics on the first day. Let them get their feet wet and then inform them that fully half of photography involves Physics. If you do this, they will be less likely to go to bed that first night wondering what they got themselves into. Well unless they are someone like Michio Kaku. Then feel free to throw as much Physics at them as you dare.
:lol: :lol: :lol: :lmao: :lmao: :lmao:
 
You can help balance the foreground & background light by "lagging the shutter". "lagging" means that you'll set a slower shutter speed. This is because when you use flash, remember that only some of the light is created by the flash, and other light was just the ambient light already availabile in the room. The flash will tend to "freeze" a subject and provide a sharp image while "lagging" the shutter (shooting with a shutter speed much slower than necessary if you only cared about the subject) will allow the camera to collect more of the ambient light for the rest of the scene.Most flashes try to maintain a "daylight" white balance temperature -- although you may find your camera actually has a white balance setting just for flash. This only matters if you shoot JPEG.
Ok, I tried using a slower shutter speed, but now my problem is the blur. It was originally set on 1/60 and then I se it to 1 which gave me a more balanced result. But then, motion blur became present. Also, should I just leave my White Balance at Auto when shooting in RAW and Flash when shooting in JPEG?
I am checking out this resource as we speak, thanks!I have another 2 questions. What about flash compensation; what does it do?Bouncing the flash on to the ceiling seems to balance out the flash, when is it correct to use the flash directly on the subject? And what does a diffuser do?
 
In TTL (through-the-lens) mode, cameras can determine the amount of light needed for correct exposure. However, this not usually the case. Sometimes you want to adjust the amount of light so you use flash compansation to make the necessary adjustments. Whether to use more or less power depends on you. It may be akin to going into manual over ride when in auto mode. Note this is different when in manual mode when power is at 100% unless you further "manually" adjust the stops to your desired effect. Though both do try to attempt the same (meaning getting the right exposure). Below is a link about flash compensation explained in lay man's terms.

http://www.photoanswers.co.uk/Advice/Search-Results/Techniques/How-to-use-flash-compensation/

Bounce flash is a nice technique to avoid "blowouts" of the subject. You can also try bouncing on walls so additional lighting can also come from left or right. Your SB-700 can tilt and swivel. So try to experiment using the walls and ceilings and with different angles. The main limit of bounce flash obviously is when you are outdoors since there is no ceiling or wall to bounce to. Main solution to this is to use a bounce card. If I am not mistaken the SB-700 has a built-in bounce card. (It is the "thingy" in the flash head in case you don't know.)

Using direct flash and bounce flash IMO depends on really how you want create your shot. In my experience, if I use direct flash my subjects are bright or blown out while the background is dark even when indoors. I have two solutions for this. I use direct flash with slow sync on to get a brighter background. But this you probably know may lead to blurred shots as slower shutter speeds are used. Alternatively, I use bounce flash to get better lighting. Best way to do this is to keep on practicing.

Diffusers soften the light of the flash to have a subtle change in the subject. You can dispense using a diffuser by using flash compensation, but IMO there are subtle differences in the shot. In my case, since I don't have a bounce card I use a diffuser when doing fill flash outoodrs. When to use it is a matter of personal preference IMO. Again practice is the key. And I believe the SB-700 comes with a diffuser box. Below is a link about diffusers.

http://digital-photography-school.com/using-flash-diffusers-and-reflectors
 
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In TTL (through-the-lens) mode, cameras can determine the amount of light needed for correct exposure. However, this not usually the case. Sometimes you want to adjust the amount of light so you use flash compansation to make the necessary adjustments. Whether to use more or less power depends on you. It may be akin to going into manual over ride when in auto mode. Note this is different when in manual mode when power is at 100% unless you further "manually" adjust the stops to your desired effect. Though both do try to attempt the same (meaning getting the right exposure). Below is a link about flash compensation explained in lay man's terms.

How to use flash compensation | Photo Answers
Bounce flash is a nice technique to avoid "blowouts" of the subject. You can also try bouncing on walls so additional lighting can also come from left or right. Your SB-700 can tilt and swivel. So try to experiment using the walls and ceilings and with different angles. The main limit of bounce flash obviously is when you are outdoors since there is no ceiling or wall to bounce to. Main solution to this is to use a bounce card. If I am not mistaken the SB-700 has a built-in bounce card. (It is the "thingy" in the flash head in case you don't know.)

Using direct flash and bounce flash IMO depends on really how you want create your shot. In my experience, if I use direct flash my subjects are bright or blown out while the background is dark even when indoors. I have two solutions for this. I use direct flash with slow sync on to get a brighter background. But this you probably know may lead to blurred shots as slower shutter speeds are used. Alternatively, I use bounce flash to get better lighting. Best way to do this is to keep on practicing.

Diffusers soften the light of the flash to have a subtle change in the subject. You can dispense using a diffuser by using flash compensation, but IMO there are subtle differences in the shot. In my case, since I don't have a bounce card I use a diffuser when doing fill flash outoodrs. When to use it is a matter of personal preference IMO. Again practice is the key. And I believe the SB-700 comes with a diffuser box. Below is a link about diffusers.

Using Flash Diffusers and Reflectors

Thanks for the links, it was some really interesting reading.
 

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