All images and text © copyright Karl Taylor.
There are two types of low light photography scenarios that I would like us to consider, the first is the easiest to undertake while the second is achievable but can require the use of more expensive equipment and some compromise to get the type of results that are desirable.
Scenario one is for low light images that do not require fast shutter speeds to freeze any action and are generally of stationary scenes or where the movement of objects adds some sort of visual effect to our image. The key image requirements to consider are:
- A longer exposure (a slow shutter speed)
- A stable platform (possibly a tripod)
- A cable release to avoid shaking the a camera (or use of the self timer)*
- The possible use of post production software to improve or remove noise created when shooting in low light conditions
*If you want to take it to extreme then a mirror lock up function to avoid the minutest camera shake on long exposures could be used, but generally speaking this will only be necessary when shooting with more powerful telephoto lenses.
Scenario two is for images in low light that require faster shutter speeds to freeze some relevant action as part of the composition. With this scenario we immediately present ourselves with a set of extra problems to overcome. Fast shutter speeds reduce the amount of light reaching our recording medium and in low light we already require more light to reach our recording medium in order to achieve the correct exposure. Before I go into more detail lets look at the requirements we need to consider for scenario two:
- A shorter exposure (a faster shutter speed, determined by the speed of movement in the subject that we wish to freeze)
- A fast lens (a lens with a large aperture to let more light through)
- High quality high speed ISO capability (the ability to record an image well in low light situations)
- High quality optics (lenses of superior quality in order to record an accurate rendition of the scene even at large aperture settings)**
- An additional light source (the ability to add our own light to our low light scene)
- The possible use of post production software to improve or remove noise created when shooting at higher ISO speeds
**Cheaper lenses generally don’t work very well at large aperture settings. Often the images will be of poor quality in resolution especially in the corners of the image as well as suffering a significant loss in colour and contrast fidelity
As you can see the fundamental requirements for both techniques are somewhat different. In scenario one the use of a tripod and long exposures mean we can shoot at pretty much any aperture we desire to either increase depth of field or maintain the lenses optimum optical quality and we can also shoot at standard or low ISO speeds to minimise any noise in our image. Although able to shoot with lower ISO settings because of longer exposures it is important to consider that low light images often contain many shadow or dark areas to the picture and these areas are where you will most notice noise in the final image. Even at low ISO speeds, noise in the shadow areas of our picture can still be a problem on long exposures. Generally speaking the more recent digital SLR cameras have excellent low noise capabilities even at relatively high ISO speeds, for example my 5D mk2 performs better than my 1Ds MkIII or my Hasselblad in low light conditions.
You can further reduce the problem of noise that would interfere with a beautiful low light landscape or cityscape in Photoshop & Camera Raw by applying noise reduction using the reduce noise filters or the settings in Camera Raw.
Another technique to get the best out of your low light images is to use a tripod and photograph your scene 6 or more times at the same exposure and then use layer stacking techniques to reduce the noise.
Because noise is random in the image by stacking the shots on top of each other in Photoshop you can cancel the noise out over a series of exposures. Either adjust the opacity of the layer stacked images or preferably by using the stacks function in Photoshop Extended to get optimum noise reduction. Applying the Stacks function in median mode Photoshop Extended it will average out all the pixels in the image to a mid point, thereby removing the random noise that has appeared at different pixel positions giving you a final image with greatly reduced noise from your shadow areas.
Whilst the above technique is great for “scenario one images” it is not so useful on “scenario two images” because we are working free hand on moving subjects meaning that no two pictures will be the same and unable to stack together in the same way. In these instances additional noise plug in software may be your best answer if the noise in the image is a problem.
Low light “scenario one” images are in my opinion pretty easy for anyone to try and yield excellent results if you just apply a bit of planning and are methodical in your techniques. Obviously good composition and finding something interesting to shoot go without saying, but by following the requirements for “scenario one” then you really can’t go wrong if you get your exposures right. Remember that shooting at night will mean your digital preview screen can look abnormally bright and may fool you into thinking the exposure is too bright, so if possible turn the screen brightness down a couple of clicks to compensate. After that it’s just a case of shooting test exposures to establish the correct exposure and the desired aperture /shutter speed combination to achieve the “look” you are after. Cityscapes at night make great subject material as you can often include car trails and building lights but landscapes and seascapes can also make great eerie low light subject matter.
Low light “scenario two” images add a few problems to getting the shot. Let’s take an example of say street photography after dark where you want to capture and freeze the motion of your subjects in a photojournalistic style. Firstly the faster shutter speeds required mean that you have to consider either using larger apertures or high ISO speeds or even both.
Large aperture shots obviously reduce our depth of field and if this is not an effect you desire then you will have to increase the ISO significantly to ensure that the amount of light needed for a correct exposure can be achieved at your given shutter speed. Personally for these type of shooting scenarios where you must freeze the action I make a compromise between a mid to large aperture setting a higher ISO speed and possibly adding a burst of flash into my shot with a shutter speed of say 1/15th or 1/30th on a wide angle lens. This way I get a bit of the best of both worlds; reasonable grain, reasonable depth of field, ambient light atmosphere and let the burst of flash freeze my foreground subject. The duration of the flash is much faster than the shutter speed and takes care of freezing the motion in the foreground while my shutter speed of 1/15th or 1/30th allows me to capture some ambient light atmosphere but is quick enough to freeze most of the movement in the background as the apparent movement is less due to the further distance of the background objects or scene. I usually apply this technique with the flash set on a low manual power and run some tests to work out my shooting distance for the correct flash exposure at a few given power settings that way I know what my flash power needs to be for a few different shooting distances such as 4ft, 7ft, 12ft. Some cameras semi auto modes with flash compensation can take care of things for you but as with all auto camera modes, you can’t guarantee the results!
It’s important to remember that with street or low light journalistic photography a bit of extra grain or noise sometimes adds atmosphere to the shot and on modern digital SLRs the noise reduction is excellent even at ISO1600. So you may find the need to add your own flash/strobe light unnecessary.
For those of you who are enthusiasts of low light photography then you’ll be glad to here of what is not too far away in technology terms. The next big step that we will see in camera technology is in low light recording capability. In just a few years from now we will see cameras capable of shooting in extremely low light conditions at higher shutter speeds with virtually noise free images. In fact I believe what is just around the corner will actually be able to see even better than we can.
All images and text © copyright Karl Taylor.
Find the tripod and camera bag to suit your needs at www.vanguardworld.com
All images and text © copyright Karl Taylor