Taking Photos in the Bend

[East Texan]

CAMERA RAW NOISE REDUCTION

Here's  a discussion on this topic - longer than you want to read but interesting.  I'm still experimenting with my situation.

http://luminous-landscape.com/forum/index.php?showtopic=29628&st=0

[East Texan]

(and be sure the long exposure noise reduction is turned ON,...)

I am just curious as to what make of camera you use. I am shooting with a Canon 50D, and from what I read from Canon and various other sources, the NR doesn't appear to make any difference when shooting RAW. I haven't shot any star images yet, but plan to soon, so I haven't tested this on my own yet, and just thought I would ask.

This question is driving me crazy... I spent all day today researching it. This info pertains to RAW files only as that is what I shoot. JPG's are handled differently in camera.

Here is what I found from the Canon Learning Center at http://www.usa.canon.com/dlc/controller?act=GetArticleAct&articleID=1407

  Third-party RAW file software programs:
 Virtually all third-party RAW file software programs, such as Adobe’s Camera Raw™
 software, will ignore in-camera settings such as High ISO Noise Reduction. Therefore, if you
 use another company’s software, you’ll generally have to use the software’s own tools to
 change the look of your finished pictures. Don’t expect the High ISO Noise Reduction you
 may have set in-camera to have any effect with most third-party software programs.


So........ High ISO Noise Reduction doesn't benefit if shooting RAW.

I have not found the definitive answer on Long Exposure Noise Reduction

There are noises that are totally random from one frame to the next, and there are noises that are the same from one frame to the next. The type you see in very long exposures is the latter, so if you have the long exposure noise reduction enabled, it will "expose" the sensor to darkness for the same period of time as the real exposure immediately after it, and subtract the second capture from the first, removing most of the time-and-heat-related noise. The downside is that the noise in the deepest shadows will increase by 41%, as that is the way totally random noise adds and subtracts (there is no diffrence between adding or subtracting with totally random noise, as it is both negative and positive in nature).


Very confusing...

More information if anyone is interested in this subject:  http://www.gdanmitchell.com/2009/02/11/hints-for-night-photography

[badknees]

(and be sure the long exposure noise reduction is turned ON,...)

I am just curious as to what make of camera you use. I am shooting with a Canon 50D, and from what I read from Canon and various other sources, the NR doesn't appear to make any difference when shooting RAW. I haven't shot any star images yet, but plan to soon, so I haven't tested this on my own yet, and just thought I would ask.

This question is driving me crazy... I spent all day today researching it. This info pertains to RAW files only as that is what I shoot. JPG's are handled differently in camera.

Here is what I found from the Canon Learning Center at http://www.usa.canon.com/dlc/controller?act=GetArticleAct&articleID=1407

  Third-party RAW file software programs:
 Virtually all third-party RAW file software programs, such as Adobe’s Camera Raw™
 software, will ignore in-camera settings such as High ISO Noise Reduction. Therefore, if you
 use another company’s software, you’ll generally have to use the software’s own tools to
 change the look of your finished pictures. Don’t expect the High ISO Noise Reduction you
 may have set in-camera to have any effect with most third-party software programs.


So........ High ISO Noise Reduction doesn't benefit if shooting RAW.

I have not found the definitive answer on Long Exposure Noise Reduction

There are noises that are totally random from one frame to the next, and there are noises that are the same from one frame to the next. The type you see in very long exposures is the latter, so if you have the long exposure noise reduction enabled, it will "expose" the sensor to darkness for the same period of time as the real exposure immediately after it, and subtract the second capture from the first, removing most of the time-and-heat-related noise. The downside is that the noise in the deepest shadows will increase by 41%, as that is the way totally random noise adds and subtracts (there is no diffrence between adding or subtracting with totally random noise, as it is both negative and positive in nature).


Very confusing...

More information if anyone is interested in this subject: http://www.gdanmitchell.com/2009/02/11/hints-for-night-photography

Long-Exposure Noise Reduction is slightly mis-named as it does not really reduce "noise", but rather thermal signal. This dark frame subtraction is applied to the raw before it is written. Although the implementation may be different among camera manufacturers the general prinicipal is similar.

[East Texan]

Yep, I finally understand.  The following is valid on Canon 40D ... probably other Canon DSLR's also.

Long Exposure Noise Reduction - When turned on, will subtract "hot spots" on exposures of 1 sec or more.  Works in RAW also.

High ISO Noise Reduction - Works only on JPGs - has no effect on RAW.  Must use post processing noise reduction on RAW.

Simple when you understand it.

One more point - heat is the culprit for noise "hot spots" on long exposures.  Best to get those dark shots in the cold of winter or wait between shots to let the camera cool down.

Thanks BK

[Terlingua50337]

I'll guarantee you this, my XTi and XSi are both noisy. I think my XSi is noisier than the XTi. You're right about the NR settings. I seem to find when I apply the NR to a Jpeg it looses alot of sharpness too.

[MilesOfTexas]

Thanks ET and BK!!!  Now it makes a lot more sense.

ET: Sorry for all the trouble, but I am grateful for your efforts!  I had dug into this about a year ago and found it to be about as clear as politicians' agendas.

[MilesOfTexas]

I'll guarantee you this, my XTi and XSi are both noisy. I think my XSi is noisier than the XTi. You're right about the NR settings. I seem to find when I apply the NR to a Jpeg it looses alot of sharpness too.

Potential loss of sharpness is what worries me the most, which is why I haven't used NR (in addition to my understanding that it wasn't worth the effort when shooting RAW).  But, now I understand there is a difference between NR (high ISO speed NR for the 50D) and long exposure NR, in which my 50D offers both options (and neither of which I have used yet).

[badknees]

The loss of sharpness by applying NR is a concern for those of us who are anal about image quality, I being one of that group. However, there are times when the difference between achieving a shot and coming up empty handed is the ability to push high ISO. In particular, low light, telephoto and action combined, make high ISO a necessity. Proper exposure is of paramount importance in reducing the noise in all but the deepest shadows of a high ISO shot. After that good noise reduction, both color and luminance, go a long way in providing an acceptable shot. In addition the ultimate presentation determines whether or not the capture is acceptable. If you intend to print large format, or view the photo at 1:1 crop, the noise will be more evident. At lower resolutions and sizes used to display on the web, the noise is less discernable. Take a look the the photo in the link below. This shot was taken under the worst of circumstances.....Poor lighting, telephoto (200 mm), wide open (f2., and 1600 ISO. Raw capture is essential, and NR was achieved by applying judicious amounts of color and luminance reduction. I think you'll agree that at this size and resolution, the shot achieves it's intended purpose.