How to take your own Astrophotography
Polar Alignment for Southern Hemisphere |
Lake Tekapo Photography |
Wide angle astrophotography examples
On this site I will try and explain what you need to know about taking your own basic star photos using a DSLR camera and there own camera lens, either just using a normal camera tripod or a German Equitorial Mount. Give you ideas on what you can do with your own camera, the settings required and introduce some of the equipment needed.
Camera Setting
On the camera we need to be able to control 4 things at the same time: Shutter speed, aperture, ISO and to be able to manual focus. Some models of camera will have a bulb setting in which case use this other wise use M (manual exposure) which will let you change both the shutter speed and aperture, the shutter speed change to bulb (bulb means that if you were to hold down the shutter buttom the shutter will stay open until you release the shutter button) and the aperture wide open (quite obviously the larger the apperture the more light that come into the camera) or use the chart below. If your camera doesn't have a bulb setting then you will be restricted to the maxium setting on the camera usually this is 30 seconds. ISO (International Standards Organization) is basically a setting on the camera to tell the sensor how much to react to light, the higher the ISO the more light you will get but at an expense of getting a lot more camera noise - so if the sky conditions are good try for a lower ISO. Heres an idea of how ISO and aperture effect the shutter speed required to gather the correct amount of light.
Exposure times required in minutes when comparing aperture and ISO
| Exposure time (Minutes) |
ISO 1600 |
ISO 800 |
ISO 400 |
ISO 200 |
ISO 100 |
| Aperture 5.6 |
6 |
11 |
22 |
45 |
90 |
| Aperture 4 |
4 |
8 |
16 |
32 |
64 |
| Aperture 3.2 |
3 |
6 |
13 |
26 |
51 |
| Aperture 2.8 |
2 |
5 |
11 |
22 |
45 |
These exposure times will give you a good amount of light for processing on the computer afterwards and are good for one shot photos, or for exposures that are going to be averaged together (not stacked). If there is a moon (over 1/4) or you live in an area that doesn't have a dark sky then your exposure times will have to be less.