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See_Jane_Run
05-16-2007, 07:06 PM
k, so I used the search function here for the forums on "noise" to see if I could find any old topics, and I couldn't.

So, since I've been studying photos here & @ flickr, I've been noticing all the noise in my photos.
Most of the threads I found were mostly aimed at noise reduction editing software.. So is that what most people do? Just edit it later? I downloaded the Noise Ninja, just have to figure out how to use it.
Otherwise, what are some steps in preventing it while actually taking the shot? I adjust my ISO back & forth to test out what works best, so far neither. Shutter??
The noise is mostly in distant type shots, for example:
http://i14.photobucket.com/albums/a314/TEMP4PICS/IMG_0234.jpg i don't think i zoomed in very far, maybe to a 4 at most. I didn't use a flash, is that what might have helped??

This one I zoomed all the way in, to a 12:
http://i14.photobucket.com/albums/a314/TEMP4PICS/IMG_0228.jpg this leads me to believe that zooming is a factor in this problem

& last, this one I'm pretty sure I used a flash & didn't do any zoom.
http://i14.photobucket.com/albums/a314/TEMP4PICS/IMG_0241.jpg
SO please & thanks for any advice. I use a canon SD 630, maybe it's not a good enough camera, I don't know.

kgosden
05-16-2007, 07:36 PM
You say you adjusted the ISO back and forth, but don't mention what it was set to for these photos. You always want to use the lowest ISO value that will allow you to take a given photo if you want to minimize noise. In the first picture flash would be of no benefit. Flash is only helpful on your camera if your subject is less than 10 feet away. In a large landscape there is nothing close enough to your camera to reflect the flash back.

The squirrel photo looks like it has been cropped or you have your camera set to allow digital zoom. This meand that when your lens has reached it's telephoto limit the camera begins to use less and less of the sensor. In other words it crops the picture in the camera. Your 6 megapixel Canon is now taking only 2-3 megapixel photos to try and magnify the center.

I really don't have any comments on the last one.

Dawoofo
05-16-2007, 07:45 PM
Noise comes in a couple of flavors: luminance and color. Luminance being that there are some splotches that are darker but essentially just a different shade of the surrounding color, and color noise where the splotches are different colors altogether (usually green, purple, etc.).

Noise shows up the most when ISO is set higher (e.g. ISO 800 will show worse noise than ISO 100), and when shutter speeds are slower (a 30 second exposure will have much more noise present than a 1/500th of a second exposure). Noise also shows up in darker areas of the picture more as well as in solid colors (such as a blue sky).

I believe some of the causes of noise are the unevenness of photons striking the sensor as well as the sensor being sensitive to electric fields (some of the more expensive DSLRs attempt to shield the sensor from the electric fields, reducing more noise than non-shielded sensors). I don't think that zooming would increase the noise unless the zooming caused vignetting or a darkening in the image, and images in the distance shouldn't show more noise unless they are darker.

The best way to avoid noise from the camera end is to use as low an ISO as you can, make sure picture is exposed with the proper amount of light, and try to have enough light present to be able to have a fast shutter speed.

For noise reduction software I personally prefer Noise Ninja. Since upgrading from my fairly noisy S3 to my XTi I seldom have to use noise reduction unless I'm at ISO 800 or more—one thing that impressed me about some of the DSLRs. Another very effective way of reducing apparent noise is to reduce or "shrink" your photo with software...an image reduced by 50% for example will show much less noise than a full-sized image.

Hope this helps. :)

See_Jane_Run
05-16-2007, 08:20 PM
You say you adjusted the ISO back and forth, but don't mention what it was set to for these photos. You always want to use the lowest ISO value that will allow you to take a given photo if you want to minimize noise. .

thank you, all very useful to me. i didn't realize how important the ISO setting was.

See_Jane_Run
05-16-2007, 08:22 PM
For noise reduction software I personally prefer Noise Ninja. Since upgrading from my fairly noisy S3 to my XTi I seldom have to use noise reduction unless I'm at ISO 800 or more—one thing that impressed me about some of the DSLRs. Another very effective way of reducing apparent noise is to reduce or "shrink" your photo with software...an image reduced by 50% for example will show much less noise than a full-sized image.

Hope this helps. :)

thank you, all really helpful to me.

i downloaded noise ninja & neat image. i found neat image easier to use, and i'm still toying with noise ninja. i'm willing to pay for a software, i just have to figure out what works best for me.

iamaelephant
05-16-2007, 09:33 PM
I use Neat Image and it works really nicely for me. I accidentally left my camera on a high ISO setting for an entire day of tramping a few weeks back and the pictures looked horrible. Net Image made most of them usable. Keep in mind you will always lose a certain amount of details in noise removal, but Noise Ninja and Neat Image have pretty advanced algorithms so most detail is retained.

John_Reed
05-17-2007, 07:49 AM
You asked if using flash would help on those landscapes of yours. NOT! Your flash only has a short reach from the camera. Your photos show noise in the sky, WAY far away, WAY out of the flash's reach. The only side benefit you might get from using flash would be that it may force a low ISO, though even that's doubtful, as often ISO is raised by cameras to extend flash range.

To reduce noise in your photos, get more light into them, by slowing shutter speed, increasing aperture. Sometimes even using a higher ISO may reduce noise, by reducing shadows in the image. Shadows are where noise tends to really collect.

See_Jane_Run
05-17-2007, 08:31 AM
To reduce noise in your photos, get more light into them, by slowing shutter speed, increasing aperture. Sometimes even using a higher ISO may reduce noise, by reducing shadows in the image. Shadows are where noise tends to really collect.

thank you, i will try again tonight just for practice.

i appreciate all the help from everyone!

Norm in Fujino
05-17-2007, 09:54 AM
If Neatimage works well for your camera's photos, I'd use it, since it's cheaper than Noise Ninja. Another one you might like to try is Noiseware. Both can be downloaded for free trial.

I use both Neatimage and Noiseware and they both work well on my camera's photos--I personally believe that there are differences in the way that software programs handle different cameras' jpegs, so it pays to try several (Noise Ninja left strange artifacts in my high ISO photos, but my cameras are Olympus).

iamaelephant
05-17-2007, 03:54 PM
I quickly ran your first image through Neatimage, here is a before and after comparison. I just did a very quick auto profile, if you take your time you can get even better results

http://iamaelephant.net/images/ba.jpg

See_Jane_Run
05-17-2007, 06:13 PM
^ wow, nice, thanks.
Do you use the paid version or the free-trial version?
I'm considering purchasing it.

iamaelephant
05-20-2007, 02:42 AM
That was the paid version but there aren't a lot of limitation with the free one. The main reason I bought it was because the free demo version doesn't save Exif data.

sla
05-29-2007, 06:29 AM
I adjust my ISO back & forth to test out what works best, so far neither.

Hi
You wrote that you change ISO. But all three photos of yours are ISO400 ;)
Maybe this is why you found them "noisy".

i don't think i zoomed in very far, maybe to a 4 at most. I didn't use a flash, is that what might have helped??
Flash would't help with "distant" photos. It is said, that SD630's flash working range is 0,5 .. 3,5m. Some cameras have stronger lamps, which give light to 7-9meters.

believe that zooming is a factor in this problem
In general zoom doesn't increase noise. But if you zoom in, the lens lets less light to get into the camera. So the camera may want to increase ISO (sensitivity), and there will be more noise.
By the way - looks like you used DIGITAL ZOOM in the second image (3xoptical * 4xdigital=12x). This is why your image looks worse. It is rather not recommended to use digital zoom. Unless you really want to. But digitally zoomed photos often look ugly, without fine details.
regards