The Shutter Speed

 

In continuous light, the shutter speed will be detrimental as the choice of shutter speed controls or prevents subject blur. It works in conjunction with the lens aperture to determine the correct exposure.By choosing a faster shutter speed, at about 1/2000, you will then be able to capture a topless model running through a castle. In this shutter speed in "Shutter priority" or "Aperture priority" mode, the digital camera will measure the light and set a wide aperture to create and ensure a perfect exposure.

 

When we use the studio flash, the main purpose of the shutter is to be fully open when we fire the flash. This can alter of cause if there is an extra light, or continuous light mixed with the flashlight. This won't affect the exposure, you will need to set your camera to manual mode and by setting the shutter speed to a speed at which the shutter will be fully opened.

 

A digital DSLR camera has a focal plane shutter, meaning a shutter plate right in front of the sensor. Simlar to two blinds, which open and close at different intervals. Just as the first one opens up and uncovers the sensor, the second blind lowers and closes. This tells us that at a slower shutter speed, the sensor is exposed to the light for a few seconds. But when we use a flash, the flash will need to fire at this precise moment to be in sync.

 

But this is where you will probably experience some problems. At faster shutter speeds the second "blind" plate starts to close way before the first one has reached the end of its full function. The affect of this is a moving plate "blind" that moves across and in front of the sensor, and this exposes a part of it at the time of taking the picture. As the plate "blind" has not fully performed its function correctly, part of the image will be covered by the shutter plate "blind" and your image will have a black line covering a section of it.

 

So without stating the obvious. The shutter speed will need to be slow enough and fully open at the time you trigger the flash. In order to capture a perfectly exposed image. Now, this varies from camera manufacturer and most manuals will advise you to input settings of about 1/250. Consult your user manual that came with your camera to verify the max sync speed for your camera. Once you know your cameras max sync speed, you will notice that your camera and flash units can't sync up properly if you are trying to shoot at a higher shutter speed. That is if you are using a dedicated hotshoe flash and not a studio flash. I would recommend setting your camera to a lower shutter speed of around 1/125.

 

It is important to remember that when shooting with a studio flash. You control the exposure by adjusting the aperture, not by adjusting shutter speed. Changing the shutter speed changes the ambient light exposure and this isn't exactly what we want. It is also worth remembering that the shutter speed has no effect on the subject blur either. In a studio set-up situation, the flash of light is very brief and it's the flash that freezes the movement, not the shutter speed.

 

The White balance

 

If you are using continuous lighting, you should set your white balance to auto, but this won't work with a studio flash as the camera can't measure the colour of the brief flash of light. It therefore is unable to measure the light from the flash or any other light from the surrounding area. You will need to then set the white balance manually. All digital Camera's will allow you to set a "custom white balance". Please consult your Digital camera manual on how to do this. When we set the white balance on our digital camera's we are in fact inputting the colour temperature of the light source and this will set the balance needed to obtain neutral colours.

 

Measuring light

 

If you are going to use your camera with continuous lighting in any of the camera settings other than manual. You will notice that your camera will measure the light reflected from the subject and will automatically set both the aperture and shutter speed if we had chosen the programme mode and the aperture that suits the shutter speed in "TV" Shutter-priority. The shutter speed that suits the aperture "AV" Aperture-priority. But these settings won't work with a studio flash because your camera's meter just can't measure for the brief flash of light. By changing your camera to Manual mode we are then able to input both the given shutter speed and aperture. We get both these figures by measuring for them with the use of a flash meter. We could keep checking the LCD preview screen or by checking the histogram to get the correct exposure. But this is time consuming and usually ends with poor results.

 

When we are ready to shoot with a studio flash, the most important things to do are to set the camera to manual mode and then the correct flash sync speed. Now each camera manufacturer has its own specifications on how to do this. To save time I will give you a generic setup. Apply this to your given camera model, and you should be fine. First set your main control dial to M to select the manual mode. Then turn the input dial behind the shutter button and set the flash sync speed to (1/200sec canon/ Nikon/ Olympus), set to (1/180 sec Pentax), set to (1/160 sec Sony). Once you have taken a flash metering reading press and hold down the +/- button then turn the input dial to set the aperture you require.