Noise in low light
By Connie
@connierebel (1557)
United States
December 23, 2008 2:06pm CST
I was wondering if anyone has some tips for avoiding noise when using a digital camera to take pictures in low light situations. I know the combination for film cameras is a fast film speed and a slow time, but I tried this and the pictures came out really "grainy". It was a nighttime scene, and I took some pictures of a gazebo that was lighted up. I think I used 1 second at 800 or 1600. I have just a regular digital camera, not a fancy one like the SLR's. But it does have night settings where you don't use the flash and just leave the shutter open for a longer time to collect a much light as possible.
Also, a my sister in law has a bunch of pictures from her wedding, and several of these are grainy also, because the lighting in the hall was not that good.
Any help you can give would be appreciated. I love photography, but I don't have the money for expensive equipment. I like to get the best picture I can with just what I have.
2 responses
@Davidarich (985)
• Australia
26 Dec 08
I'm afraid the advice you have had so far will not reduce the noise in your pictures. It is the equivalent of feedback in a sound system and caused by similar factors (which is why it is called "noise"). The problem is actually that the signal to noise ratio is too low.
Any increase in ISO is equivalent to turning up the gain (volume), and adding stops via exposure compensation or a slower shutter speed magnifies the problem.
If you can shoot at a higher shutter speed you will have less noise, but you have to keep your ISO below 400 with any camera with a small sensor. That means you will have to add more light (a flash is possible, but your built in flash is limited to about 12 ft (4 metres), but sometimes you can turn on extra room lights or use a reflector to get more light onto the subject.
Certain subjects are affected more by noise: large areas of the same tone or colour show more noise, and dark areas are worse than light ones. Keeping that in mind as you compose your shot might help.
The only real solution is to get a camera designed for the task. I can shoot at ISO3200 in poor light and not be troubled by noise using a digital SLR with a CMOS sensor. THe larger sensor means that there is more space for larger pixels, so less electrical and heat contamination on the sensor, and more light gathering capacity; and the CMOS sensor has noise reduction hardware at each sensor site.
It is now possible to buy compact cameras with CMOS sensors, and to get compacts with SLR size sensors. These may be an option until you can afford an SLR.
Apart from using complex software like Photoshop, Clear Image, Noise Ninja and other special purpose programs do a good job in reducing the impact of noise; some have a free version. Try www.neatimage.com or do a search for Clear Image or Imagenomic.
@connierebel (1557)
• United States
3 Jan 09
Is ISO the equivalent of film speed in regular film cameras? Because I thought that for low light with film, you should use long exposure time and a very fast film speed. That's why I used a higher ISO. I guess I was mistaken. Next time I'll try a lower ISO and see if that's better. I was not at the wedding, so I don't know if the flash was used, but for my outdoor pictures, the flash would not have worked because it only has a limited range. I guess the best thing for me to do is experiment with various different settings for the same scene and see what comes out best. Thanks for the explanation.
@Davidarich (985)
• Australia
3 Jan 09
Yes, ISO is equivalent to film speed: you were not mistaken. And just as higher speed films tend to be grainier than slower films, so setting a high ISO result in noisier images.
The problem is that while film grain is related to random clumping of silver salts, noise is caused mainly by heat and is much more regular and mechanical. Grain can enhance some photos; noise just degrades the image. This is not just a matter of taste (though aesthetics does come into it): grain is a useful tool to enhance atmoshere while noise only degrades detail.
Invest in a good noise-reduction software package until you can afford a better camera.
@im_anna (717)
• Philippines
26 Dec 08
aside from thr ISO settings, I also use the +/- Exp of my digital camera to +2 or +1 depending on the lighting, sometimes I also use the flash, then edit it using Adobe Photoshop. Most of the time, when lighting is too low, I always make sure I take 3 shots, one with flash, one with high ISO setting, then one with additional +1 exp just to make sure I am satisfied with the shot, specially when the shot is too important to pass away. photoshop for me is too usefule since I don't have a dslr yet specially since there is a big difference with ordinary digital camera & DSLR shots.
