DSLR Training White Balance
This DSLR Training White Balance (WB) is about how colour affects your photo.
When we look around what we consider to be white light may in fact not be. The expression goes “not all light is created equal”, it is in fact the colour of light that is the issue. A good example of this is the light in the morning, have you noticed that red brick buildings looks redder?
To standardize, direct sunlight at noon is considered to be white light and all light sources are compared to this as the standard. This is why you have different white balance temperatures for different light, i.e. cloudy, shade, tungsten lights. Taking photographs under different lighting other than sunlight and not adjusting the white balance will give a red, green or blue tint to the picture.
Correcting White Balance
Using the correct WB is about removing the colour casts so that items appear white that are white in your photo. Setting the correct WB takes into account the colour temperature of the light source.
Colour temperature of light is expressed in kelvin (K). The range is from 1000kelvin (K) up to 10000kelvin (K), with direct sunlight being in the middle of the table. You need to bear in mind that flash guns operate in the direct sunlight 5000-5900k range.
The images below demonstrate the effect of changing colour temperatures.The original image was shot at WB of 5100k in direct sunlight. To demonstrate the difference that WB makes this image has been used and altered to different WB values. You can see how the light changes from blue (cold) to Red/Orange (Warm).
Note that the light goes from Red (1000K) through yellow, pale blue to Dark Blue (10000K). This gives the impression of warm through to cold. You can also look at this as being sunrise to sunset. In reality the camera tries to correct the colour cast and images at 1000K appear blue and at 10000K they have a red tinge. This comes about as the camera tries to compensate with a the green-magenta shift.
The following scale from www.digitalcameraworld.com shows how the change occurs over the range.
The above video shows you what you need and how to set a custom white balance.
Capturing good photographs, requires the camera to be set up correctly. As a beginner setting the camera to the white balance symbol for the light at the time of shooting is a good start.
As you become more proficient getting the colour right in a photo is critical; you don’t want the image to be to warm or to cold. To set the camera correctly you need an 18% grey card. This card is shot under the lighting conditions that you are going to shoot under.
To set your ISO, set the card up and fill as much of the lens as you can, take the shot. Next check your cameras manual to set a custom white balance. use the grey card image you took to set the custom white balance. By setting a custom WB this enables you not to touch the setting when shooting under that lighting condition. If you change light i.e. go indoors then you have to use the same procedure to reset the WB.
How it all pulls together
The DSLR Training White Balance video demonstrates the changes in WB or image colour. Its noticeable how the colors change as they go from red to blue. You can also the feel the change from cold to warm. Setting the correct white balance displays the areas that are white in your image as white with no colour casts.
Using the aperture setting, set your camera WB to each of the WB symbols. Using the same subject take a picture by setting the camera at ISO100 and f8.0.
Download your images onto a PC. Look at your images, if you can side by side or slideshow them. Can you see the difference in the colour of the images?
What to do next
If you would like to receive more of this series contact Martin here. Want more info on a given subject to be covered, drop him a line.
DSLR Training ISO (new speak for film speed).
This DSLR Training is on the subject of ISO. The following images are the same scene taken at different ISO’s
Film originally was rated as American Standards Association (ASA) this indicated the rating of speed the film recorded the image. To use film correctly, the camera had to be set at the rating of the film, i.e. ISO400 (ASA400). The disadvantage of film is that you couldn’t plan to shoot different locations in different lighting conditions. You could change the film speed but you had to note where you did in order to inform the printer when the film was printed. Unlike today this had limitations on what you could photograph.
Simply put ISO is the level of sensitivity of your camera to available light. A lower number the sensor is less sensitive than at higher numbers. With increased sensitivity you can capture images in low light levels.
ISO has been in use since 1974 and stands for International Organization for Standardization. It is used for film and digital cameras with the same limitations for film being current today.
With modern digital cameras the ISO range is tremendous. They range from at the low end at ISO100 -ISO32000 or higher at the high end of the range. The big advantage is that you don’t have to change film to capture images in low light. The disadvantage is that as the ISO setting moves higher, you introduce noise (grain) into the picture. To help reduce noise and grain, software can be purchased to help keep this to a minimum. Not a problem at the lower end, but it is more noticeable at the higher end of the scale.
The video below made for DSLR Training shows the differences that the ISO makes on different settings.
The video demonstrates that noise is more noticeable the higher you have the ISO set. It is best to take your photo in the lowest ISO setting that you can achieve.
Using the aperture setting, set your camera to ISO100 and use f8.0. Find a bottle of dark liquid (red wine) and photograph this is on your kitchen worktop near a window.
Repeat at ISO500 AND ISO4000. Download your images onto a PC. Look at your images at 100%, can you see the noise in the images?
When you have tried this, now go ahead and try different ISO’s up to 1000. Note where the grain noise becomes visible.
What to do next
If you would like to receive more of this series contact Martin here. Let him know if there is a subject you would like covered.