How do I reduce the noise in this image / prevent noise in future images?

Question

I'm Canon Powershot A510. I took photography as an elective, and I normally look for pictures later in the evening, as I find it more enjoyable to walk then. The problem is that - especially considering it's winter here - that it gets dark pretty early. This isn't a huge problem, as there are some things that look better in the dark, but I keep running into issues with noise.

For example

The camera has four ISO settings, 50, 100, 200, and 400. I used 400 for the shot, a 5.5 f-speed (the lowest it would go for that zoom level) and a 1/60 second shutter speed.

I have photoshop, but the filter > noise > reduce noise doesn't do much. How can I reduce the noise on this image and prevent it in future images?

Also, any constructive criticism is appreciated. I'm not a big fan of photography, but I wouldn't mind taking pictures a little better.

Answer 1

The darker the image, the more noise you're going to get. The way to avoid noise is to get more light to the sensor. To do that you'd need to use a tripod or monopod and increase the exposure by a few stops. In post processing you can lower the exposure back down if you want the image to look as you saw it.

If I'm not mistaken, most of the noise in your image looks like color noise. You are right that the photoshop noise reduction filter isn't very effective. But Adobe Camera Raw is good at removing noise, especially color noise. Open your image in ACR, go to the Details tab and move the Luminance and Color noise sliders to the right. You can usually move the color slider all the way over, but you'll lose sharpness if you move the luminance too far.

In this particular image, most of the noise is in the sky which doesn't have edge detail to worry about losing, so I would take this approach:

• open the image in adobe camera raw
• apply 75-100% color noise reduction, and maybe 25% luminance
• open as a smart object
• make a copy of the smart object
• double click the copy to open back in camera raw
• this time apply 100% luminance noise reduction (will result in some loss of detail)
• save back to PS
• use a mask so that the luminance noise reduction layer is only visible inthe sky area.

There are 3rd party plugins for noise reduction. Noise Ninja is probably the most popular. I use Topaz DeNoise and it's affordable and very good. Both certainly go beyond what ACR and PS can do.

Answer 2

I hate to answer a question with "buy something different", but I think that's really the answer here. Camera sensor technology has come a long way since in the seven years since this camera was new, and even in 2005 it was not at the top of the budget-camera heap for low noise. (Reviews from the time suggest avoiding ISO 400).

So, while there are some things you can do to get slightly better results, in order to see real improvement, I suggest shopping for a replacement. Pretty much every camera on the market today will do better for noise and for other aspects of image quality, including the cameras built into high-end cell phones.

Alternatively, you can embrace what you have and learn to live with the faults. If the composition is great and the subject compelling, the technical qualities may not be a big deal.

Answer 3

Concerning future images, the first thing I would try would be to use a lower ISO. In your case, instead of using ISO 400 I would go with ISO 100 or 50.

Note that lowering the ISO while maintaining the aperture would imply increasing the shutter speed. If with ISO 400 you needed 1/60s, with ISO 100 you would need 1/15s and with ISO 50 you would need 1/8s.

At those slower shutter speeds (and your zoom level) you would need to keep the camera really steady, and a tripod or any other support would be highly recommended. Even the pressing of the shutter would shake the camera too much, so the best option would be to use the camera timer (2s would be enough) to trigger the shot.

After you make sure the camera has captured the picture with the lowest noise possible for it, any other corrections would have to involve post processing software like the ones mentioned in other answers.

Answer 4

You just might be in luck. I had a canon Asomething series camera. It had the ability to shoot "dark frames" when the shutter speed was < 2 seconds. It would then subtract the dark frame from the scene and this really helped with noise. Check out this shot taken with this camera. You will, of course, need a tripod, but that camera is so light a cheapo will do. And yes, like the others said, lower the ISO to 100.