Most cameras have automatic settings for sunsets. All that happens in this is that the white balance is being alerted to adjust for the orange light that seen at sunset. Usually, you can also adjust this in manually in camera or in post production better result if you shoot in the RAW file format.
Another way to take a sunset photograph is to use a ‘graduated filter’. This is a piece of glass or plastic with a darker grey tone, that fades to clear at the centre of the filter. What this allows you to do is darken the sky to correct exposure for the foreground.
Photographing the moon is quite different from other night photography, partially because of its distance from the camera and partially due to the fact that the moon and earth refuse to sit still for the photograph. Normally a moving subject can be captured sharply using a very fast shutter speed. In low light situations, however, this is not possible as you would wind up with a completely black image.
The ‘staircase to the moon’, for example, is a natural event in Broome, Western Australia. Here the moon rises over, and is reflected in, the mudflats so that it looks like a staircase or ladder to the moon is being built.
Given the vast distance between the mudflats and the moon, and the darkness, it is virtually impossible to take a photograph where the light reflected on the mudflats and the moon is also in focus. Were it not so dark, allowing the shutter speed to be very fast, this might be easier, as it might be possible to capture the moon before it moved. But given the required long exposure, a composite image of ‘the staircase to the moon’ must be made. One photo must be taken focussing on and with the aperture adjusted for the light on the mudflats. Another photo must be taken of the moon.
When thinking about what exposure to use when photographing the moon, it helps to think of it as effectively being just a giant reflector. The moon is just reflecting the sun. To see the details in the moon surface it’s a lot shorter exposure around 125th at f8.
Bracketing and HDR Photography
This type of photography mainly came about to extend the limitations of digital cameras.
HDR refers to High Dynamic Range; the dynamic range is the amount of variation of light or light contrast, in the photo. A HDR photo has had the contrast enhanced to more that digital cameras today are able to provide. Although digital cameras and in particular their sensors are improving, it is widely said tradition film has a wider dynamic range. Dynamic range is the range of light a photograph can capture, from the lightest highlight to the darkest shadows. For example a typical landscape has detail in the whites of the clouds at the same time detail in the dark shadows. Some of the limitations of digital cameras mean that some of these details may not be captured.
HDR files capture 32bits of information, recording colour and light from highlight to shadow details. Most computer monitors and printers cannot output or show all that colour and light information. A second process called ‘tone mapping’ is used to compress all that information into 16bits for printing and display purposes. There are a variety of programs used to combine the files, then tone map the image into a 16bit file.
Examples of programs: Photoshop Cs2 and above, Photomatix Pro and HDR Efex Pro.
The method for capturing the HDR image varies from taking 1 to 11 photographs of the scene.
One file method.
Recommended you shot in the RAW camera format.
Using multiple files (3 bracketing images)
Take your exposures 2 stops apart, e.g. for 3 exposures 1/1000sec F/8 , 1/250sec F/8 and F/8 1/60
Note: Bracketing means that is three shots, one using the camera remote, one that overexposes, then one that underexposes and then combining them. Some cameras have an auto bracketing setting and do it for you. It dies use up large amounts of space on a memory card but will give you a selection of photos to choose from for a particular shot.Using more multiple files (7 Bracketing images). Take your 7 exposures 1 stops apart eg: for 7 exposures 1/2000sec F/8 , 1/1000secF/8, F/8 1/500, F/8 1/250, F/8 1/125, F/8 1/60, F/8 1/30 and F/8 1/15.
The photographs are then laid on top of each other using photography software. The software aligns them and combines them into a single file with 32 bits of information containing the full dynamic range of the scene. Then the image is tone mapped to fit into the 16 bit file which then can be displayed or printed.
Important points when taking multiple bracketed images for HDR
Use a tripod to eliminate movement.
Vary only the shutter speed, as ISO and aperture can cause alignment and detail problems.Pick scenes that are stationary, as moving object can cause problems with the image alignment and look/ appeal and clarity of the shot.