Noise on long exposures at night

[flugelboy]

Ok, I have a digital camera (as most of us here do). I've seen many night-time shots with exposrures at or above 1.5 seconds with absolutley no noise at all. A I have particularly noticed this with all of the recent fireworks shots. Many that I have seen have completely dark backgrounds with no noise and I'm wondering how to do this. Is it done in the camera settings or Photoshop or a combination of both?

Here is an example of what I'm talking about.
This photo was taken at F8 with a 1.61 second shutter. No post processing (other than cropping) has been done.


http://www.chadwhite.com/Portals/0/TTTGallery/July%204/IMG_0447.jpg

[Aylwin]

Which camera?

[vfilby]

You may also want to post the ISO speed you used along with the rest of the EXIF data.

Vince

[Persian-Rice]

I dont think the exposure time will have an effect on noise as much as ISO will.

Mind you proper exposure will also reduce noise, and from this picture, it looks a little over exposed.........

[RichardtheSane]

I dont think the exposure time will have an effect on noise as much as ISO will.

Mind you proper exposure will also reduce noise, and from this picture, it looks a little over exposed.........

With digital exposure time does have a significant effect on noise, however slight over exposure (expose to the right on the histogram) will reduce the noise.

Quie a few of the longer exposrues here are done with the 10D and 300D, and these cameras have much better control over digital noise than compacts such as the A80, S50 and the G3...

[Aylwin]

Quie a few of the longer exposrues here are done with the 10D and 300D, and these cameras have much better control over digital noise than compacts such as the A80, S50 and the G3...

Exactly. That's why I asked. I used to have a compact and this appears to be the same type of noise.

[flugelboy]

Thanks for all the responses. I'm using the Canon S1 IS with iso200. Manual focus at infinity. Highest resolution available with the least amount of comression.

I'm at work right now and don't have the rest of the data with me.

[vfilby]

I think that you would be better of shooting at ISO50 (if it is on that camera) with a longer exposure. Because of the small sensor size noise is a big problem on the consumer point and shoots.

Alternatively you can try a noise reduction program. There is a free one called noiseware. It has been discussed here but I don't have the link. Happy hunting.

Vince

[timmyquest]

With digital exposure time does have a significant effect on noise, however slight over exposure (expose to the right on the histogram) will reduce the noise.



This is kind of a misconception.

It's not that over or under exposed photos have differnt noise properties, it's that darker areas are more prone to noise. When a photo is less exposed well, obviously it will have more dark areas.

When shooting at night typically your going to have a subject surrounded by darkness. The firework in his photo is slighty overexposed, but the sky in the backround is underexposed...very dark thus lots of noise.

As stated by others Lower ISO and a better camera will take care of this noisy issue.

[stopbath]

Video noise in a digital image is ALWAYS there. Under normal exposures, the video noise is so small compared to the true image data, that it is not noticeable...

As with grain in a film image, there is always underlaying grain or video noise...

However CCD's exhibit more noise as the exposure is longer as the noise increases due to extra heat.

ISO settings are merely an multiplication of image (and noise) to create a correct exposure, the CCD is NOT more sensative.

When exposing longer, or upping the ISO, you are increasing the levels of visable noise in the image.

[RichardtheSane]

With digital exposure time does have a significant effect on noise, however slight over exposure (expose to the right on the histogram) will reduce the noise.



This is kind of a misconception.

It's not that over or under exposed photos have differnt noise properties, it's that darker areas are more prone to noise. When a photo is less exposed well, obviously it will have more dark areas.

When shooting at night typically your going to have a subject surrounded by darkness. The firework in his photo is slighty overexposed, but the sky in the backround is underexposed...very dark thus lots of noise.

As stated by others Lower ISO and a better camera will take care of this noisy issue.

Sorry, I should have been clearer on what I meant.

If you shoot raw and over expose the image then pull the exposure back with the raw conversion software you resulting image will have less visible noise.

I don't dispute the stated facts that lower ISO and also larger sensor size will significantly improve noise too... and the lengh of the exposure is not a misconception :)

[Aylwin]

I'm using the Canon S1 IS with iso200. Manual focus at infinity.

I'm not sure about the S1 but with my old G1, I could never get anything meaningful at ISO200. And very rarely did I use ISO100. Most of the time it was left at ISO50.

For shooting fireworks, ISO50 with higher f/stop and longer exposure time might work better for you.

[flugelboy]

I think that you would be better of shooting at ISO50 (if it is on that camera) with a longer exposure. Because of the small sensor size noise is a big problem on the consumer point and shoots.

Alternatively you can try a noise reduction program. There is a free one called noiseware. It has been discussed here but I don't have the link. Happy hunting.

Vince

Thanks everybody for the help. It looks like I need to try lower iso settings. As for my existing photos, this program works wonders! I found it just by searching for Noiseware on Google. It was the first link on the list.

Here is the retouched photo using it's default settings.

http://www.chadwhite.com/Portals/0/TTTGallery/July%204/IMG_0447_filtered.jpg

[vfilby]

I am glad that you like it. You may also want to try Mahesh's technique with fireworks. Set a long exposure (20s) and cover the lens up with a black card, then just remove the card for each burst.

Vince