| Author | Thread |
|
|
05/27/2008 05:05:52 AM · #1 |
|
|
|
05/27/2008 05:59:17 AM · #2 |
yes, but why bother?
Shooting hi-res and resizing afterwards does the same trick.
Message edited by author 2008-05-27 05:59:28.
|
|
|
|
05/27/2008 11:00:08 AM · #3 |
| Well, for one, more photos on the memory stick, but that's about all I can think of. |
|
|
|
05/27/2008 11:36:31 AM · #4 |
| We debated this in detail over in the S5 group on Flickr, since noise is the big problem with that camera. The general consensus was that shooting lower res would not affect noise, as the pixels on the sensor are the same size and the lower resolution image is being scaled down from the native resolution version that the sensor is actually picking up. |
|
|
|
05/27/2008 11:44:06 AM · #5 |
Shooting at lower res will not decrease noise. Like  yospiff said, the noise comes from the size of the pixels and how close they are together, and since you aren't changing the actual pixel size, it doesn't affect the noise issue.
|
|
|
|
05/27/2008 11:48:56 AM · #6 |
OK, then one other question: Why do some pocket cameras have to decrease the resolution in order to shoot at the highest ISOs?
EDIT: Not that you should be doing that anyways <_<; I'm just curious.
Message edited by author 2008-05-27 11:49:13. |
|
|
|
05/27/2008 11:52:59 AM · #7 |
I assume they're grouping pixels (in software) into larger light gathering sites - interpolating the image so to speak.
The best way to avoid the noise it to properly expose or expose a tad hot if possible. Pushing a stop later in PP will only make things worse.
|
|
|
|
05/27/2008 12:20:41 PM · #8 |
| lowering the resolution makes noise less noticeable when viewed at 100%. There is the same percentage of overall noise. On P&S lower res. for higher ISO's is just a compensation for noise, to make the picture bearable (well, to some I guess). |
|
|
|
05/27/2008 02:53:51 PM · #9 |
Let's straighten this out... there are two types of noise we need be concerned with:
1.) Random noise
2.) Fixed pattern noise
The first type is due to a couple things, namely thermal noise in the electronics and noise that is actually present in the received image (statistical noise in photon arrival frequency).
The second type is due entirely to electronics, and has to do with the varying sensitivity of individual pixels and variation in the associated electronics.
Both types of noise *will* be reduced by reducing image size. The reason for this is that you are averaging the values of multiple pixels. For instance, if you take a 12Mpx image and reduce it to 3Mpx, you've averaged 4 "input" pixels to create each "output" pixel. Because of a statistical property called the "central tendency of the mean" there will be less variation (noise) in the averages than in the starting values, thus less noise in the final image.
On the practical side, it's probably better to shoot at full resolution and down-sample later because you can control the process. You can use the more powerful algorithms available in photo processing software, compared to the more simple algorithm (because of limited camera processing power) available in-camera. |
|
|
|
05/27/2008 04:15:14 PM · #10 |
Originally posted by kirbic:
Let's straighten this out... there are two types of noise we need be concerned with:
1.) Random noise
2.) Fixed pattern noise
The first type is due to a couple things, namely thermal noise in the electronics and noise that is actually present in the received image (statistical noise in photon arrival frequency).
The second type is due entirely to electronics, and has to do with the varying sensitivity of individual pixels and variation in the associated electronics.
Both types of noise *will* be reduced by reducing image size. The reason for this is that you are averaging the values of multiple pixels. For instance, if you take a 12Mpx image and reduce it to 3Mpx, you've averaged 4 "input" pixels to create each "output" pixel. Because of a statistical property called the "central tendency of the mean" there will be less variation (noise) in the averages than in the starting values, thus less noise in the final image.
On the practical side, it's probably better to shoot at full resolution and down-sample later because you can control the process. You can use the more powerful algorithms available in photo processing software, compared to the more simple algorithm (because of limited camera processing power) available in-camera. |
Lies, all lies! |
|
Home -
Challenges -
Community -
League -
Photos -
Cameras -
Lenses -
Learn -
Help -
Terms of Use -
Privacy -
Top ^
DPChallenge, and website content and design, Copyright © 2001-2025 Challenging Technologies, LLC.
All digital photo copyrights belong to the photographers and may not be used without permission.
Current Server Time: 12/28/2025 12:50:07 AM EST.
