How to take long exposure pictures with a camera?

Answer 1

Most good cameras will take quite long exposures automatically. Anything longer than 1/30 sec and you will need to either use a tripod or support the camera against shake (a bean bag is good for this).

You still need to meter for the exposure - but you may want to set the time manually. If the meter cannot calculate the exposure you can experiment - use the B stop (it stands for bulb) which most good digital and film cameras have and try a few exposures.

Film suffers from a thing called reciprocity failure for long exposure. This means that with 1/2 the light you need more than twice the exposure. You need to allow for this.

Digital suffers badly from noise on long exposures - some cameras can automatically compensate for this by doing a second exposure of the same length with the shutter closed to assess the noisy pixels.

Answer 2

Assuming you want the immediacy of a digital camera, you need one with a long exposure or B option.

However, if you want to get pictures from a telescope there are some interesting possibilities using modified webcams which can give some excellent results. A good starting point is the QCUIAG site. This will give you lots of pointers for some methods of modifying webcams to use in astrophotography.

Another way of making long exposure photos is known as stacking, where lots of shorter exposure images are added together or stacked. The result of this is that random noise cancels out and the image gets sharper and clearer. Current software can even get rid of start trails by automatically shifting the images while stacking. Although it's better with a modified webcam, this also lets you do this with an unmodified webcam attached to a telescope with a simple connector or even a video camera. (also on the QCUIAG website)

Finally, if you want to play around with long exposures and need a sensitive webcam, Philips SPC 900NC Pixel Plus 1.3 MP is currently available and is absolutely brilliant in low light, having good sensitivity and low noise. It can be used as stock as a webcam for long exposures and will work just by the light of a monitor in a darkened room with excellent results. It looks relatively expensive compared to other webcams, but for this purpose I've got one and I couldn't believe the quality of it.

Have fun!

Answer 3

You will have to read the manual that came with your camera. The manual will tell you how to correctly take pictures having a long exposure. It's just a matter of changing the settings on your Camera is all.

Answer 4

With film it is easy just do a time exposure. With digital it is more complex if you wish to use a webcam you need to modify it. Do a search on webcams and you will find many links

Answer 5

You need a timing mechanism