Image perturbation caused by electronic transformation and processing.
74
votes
4answers
3k views
What is “ISO” on a digital camera?
What is "ISO" in general, and how is the scale defined?
How does the ISO scale for film speed differ from ISO sensitivity as used in digital cameras?
Is lower ISO always better?
22
votes
3answers
2k views
Why is the blue channel the noisiest?
It is widely observed that the blue channel in digital cameras is the noisiest. I've certainly noticed that with my camera. Why is this?
Is it an artifact of some particular technology (e.g. Bayer ...
19
votes
8answers
2k views
How can I reduce the noise present when taking pictures without lowering my ISO?
I know that high ISOs tend to produce more noise, and some cameras' software can handle that noise better than others, but are there any other settings or conditions tha affect visible noise?
I'm ...
19
votes
2answers
1k views
What is noise in a digital photograph?
What kinds of effects are present in digital images that are referred to as "noise"?
What are the different sources of noise?
What causes each type of noise?
What are the characteristics of the ...
17
votes
5answers
2k views
What is so special about ISO 1600?
I have heard many times that to minimize noise, the highest ISO you want to use is ISO 1600, and that no matter what camera or sensor you use, once you have passed this (ISO 1600) threshold, the noise ...
12
votes
8answers
3k views
Why aren't my night shots sharp even when I shot at ISO 100 on a tripod?
I recently purchased a tripod because I really want to do some night photography. I have tried practicing with street lamps, moon shots etc with my Canon 550D and 70-200 f/4L and most of them are shot ...
11
votes
1answer
312 views
What is the statistical distribution of sensor noise?
Sensor noise is a random variation in pixel values, but what kind of random is it? Does it follow a normal distribution, one of the gamma distributions, or something funky like an F distribution?
...
10
votes
11answers
600 views
What noise removal tools work best, and why?
Can anyone recommend some good noise removal tools, free and commercial? Should support RAW and JPEG. Are certain tools better than others in particular situations? Do some integrate better with other ...
10
votes
3answers
726 views
Does the order of sharpening and noise reduction matter?
I have been shooting for more than three years, but I never do too much in post-processing. I tend to be strict and keep in mind that PP can only do little to save an otherwise-great photo.
I was ...
9
votes
8answers
749 views
Is it better to shoot with a higher ISO, or use lower ISO and raise the exposure in post-processing?
Suppose there are two photos taken in the following scenario:
Scenario 1 - Photo taken using ISO of 3200.
Scenario 2 - Photo taken using ISO of 100.
Both photos are taken in a medium light ...
8
votes
3answers
494 views
How does averaging images or lowering resolution reduce noise?
This answer lists 3 techniques to reduce noise:
Keep the camera's sensor cool.
Take a burst of photos, then average them.
Lower the resolution.
Can someone shed more light about the last two ...
8
votes
1answer
204 views
Why doesn't noise depend on exposure time?
In the post Why do cameras use a single exposure rather than integrating across many very quick reads? an important question was if the noise depends on the exposure time or not. By noise I mean the ...
7
votes
4answers
888 views
Astrophotography picture with too much noise. How do I correct this in postprocessing?
This is the Milky Way above Kakadu National Park, Australia, and my first try at astrophotography.
Thirty second exposure, f/4.0 at 17mm with ISO 12800 (!!) which in hindsight probably was way too ...
7
votes
3answers
209 views
Is Poisson Noise (“Shot Noise”) a significant source of noise for typical photography?
In this answer, @jrista states that even a camera with a perfect, noiseless sensor would still have noise due to "Poisson noise" aka "Photon Shot Noise" - noise caused by the random variations of ...
7
votes
2answers
531 views
How to test noise?
I'm just looking for what's the best technique to test for noise on a camera.
Like what settings are best? What type of photo is best? What lenses should I test with? Like those sorts of things. ...
7
votes
2answers
549 views
Why are sensors less sensitive to blue light?
This is a followup question to Why is the blue channel the noisiest?. The simple answer to that question is that sensors are less sensitive to blue, and therefore require more amplification, which ...
7
votes
2answers
654 views
Does the human eye experience noise as a camera would?
I've noticed when I am in very low light (light that isn't in the same room I'm sitting in), when my eyes adapt to the dark that I see colored particles. Do these colored particles resemble noise in ...
6
votes
7answers
1k views
Cause of grainy photos?
Whenever I view my 12MP photos on my computer at 100% zoom (they're roughly 4200x2400), there always seems to be a lot of grain and noise to the image quality. What, specifically, causes this and what ...
6
votes
2answers
471 views
Where does the noise come from in a long exposure?
I created another test. This time I exposed for 36 minutes, because I wanted to test star photography. This is not meant to be a nice photo; I really just tested.
Camera was inside the house behind ...
6
votes
4answers
806 views
Does noise in images depend upon “Megapixels” or “ISO”?
I have a question about image quality. Does noise in an image is depends upon "Megapixels" or on "ISO"?
6
votes
3answers
252 views
How much does in-camera image processing affect noise on Canon DSLRs?
I've found out that some of photos take with my 5D MkII have more shadow noise than I like. I know there are some obvious settings that affect this, such as ISO a noise reduction settings. But there ...
6
votes
3answers
1k views
Is it me or is the Lightroom's zoomed out preview inaccurate in displaying noise and color?
I'm having some trouble with the Lightroom viewer (In develop mode) when zoomed out. Look at this picture:
See how the sky seems to have a lot of chroma noise
Now check the zoomed in version (Of ...
6
votes
2answers
440 views
What is the source of this multicolored noise in these samples?
I shot many long exposure photos (from 5 minutes to 30 minutes) back in December of 2010 with a two month-old Nikon D7000 and Tokina 11-16mm f/2.8 lens. The photos I took had very little noise. I ...
5
votes
2answers
222 views
Why photos taken with flash appear to have less noise?
I have not verified this on pixel-peeping level. But I have observed that photos taken with flash (built-in one in my case) appear to have very less noise at ISO 800/1600 than the ones taken without ...
4
votes
4answers
349 views
How do I properly determine which camera is better in low light?
This question is motivated by the fact that I'm trying to decide between the the Canon 5D Mark III and the Nikon D800. I really would prefer the one that will perform better in low light.
As far as I ...
4
votes
4answers
491 views
Is higher ISO noise evenly distributed, or does it affect colors differently?
It's obvious that higher ISO affects the photograph by adding noise or grains.
But will that grain or noise be distributed equally over all parts of the photograph, or will it specifically affect ...
4
votes
4answers
659 views
How can I tell if two pictures were taken with the same camera?
Is it possible to identify images (without exif data) and link them to the exact same camera? If so, I'd like some software recommendations to get the job done.
I have two photos that I'd like to ...
4
votes
2answers
390 views
Why does Nikon warn about banding at high ISOs when using autofocus on Nikon D4 or D800?
Nikon says that banding may occur at high ISO sensitivities with autofocus on the D4 or D800:
D800
Noise in the form of horizontal lines may appear in pictures taken with AF-S Zoom Nikkor 24-85 ...
4
votes
1answer
191 views
When is high ISO noise not noticeable?
I noticed that sometimes when taking pictures with my D5100, they come out with very little visible noise with ISO 800 and up, for example this picture. It was taken at ISO 1600 if I remember ...
4
votes
1answer
200 views
How can a newer camera increase ISO while decreasing pixel size?
I am a bit confused as I am considering to upgrade my canon 350D to 600D. The pixel size has reduced from 6.4 microns to 4.3 microns, however, top ISO has increased from 1600 to 6400. How did that ...
4
votes
4answers
524 views
What is causing increased noise in my recent photos?
In the last two shoots I've taken I have noticed much more noise in the resulting photos. In the first instance, I put this down to my fault, as I was shooting at high ISO levels, but in the second ...
4
votes
1answer
329 views
what's the relation between sensor size and image quality (noise, dynamic range)?
I'm reading this description on sensor size:
Digital compact cameras have substantially smaller sensors offering a
similar number of pixels. As a consequence, the pixels are much
smaller, ...
4
votes
2answers
110 views
What is the nature of noise in small-sensor cameras, and can it be overcome in the future?
What is physical nature of noise in small-sensor cameras? Is is thermal noise in the semiconductor?
Is there hope that in couple of years, noise in small sensors will disappear, and small sensors ...
4
votes
1answer
378 views
What do the different noise reduction options in Silkypix mean?
I'm playing around with RAW files in Silkypix that came with my Panasonic camera and I am thoroughly confused by the sliders for the noise reduction and the Silkypix manual isn't of much help (at ...
3
votes
4answers
539 views
How can I keep my camera cool on a budget?
Is there a way to cool the camera without buying a new hardware? How do you determine that the camera is NOT cool ATM? What temperature can be considered hot for the camera sensor? Does cooling really ...
3
votes
3answers
2k views
This doesn't seem very sharp…is this normal?
Body: T2i
Lens: Kit, 18-55mm f3.5-5.6
I went to shoot a sunrise this morning at the beach and got some great pictures, but when I uploaded them to some light post-processing, I was slightly surprised ...
3
votes
4answers
227 views
Does micro 4/3 have an advantage in low light due to aperture equivilence?
Recent Micro Four/Thirds sensors seem to have improved their noise performance significantly.
I own a Canon 5D Mark 2 full frame DSLR and am considering purchasing an Olympus OM-D EM5 micro four ...
3
votes
1answer
117 views
RAW export in Aperture giving square “grid” pattern over noise
I have a RAW photo in aperture that has quite a lot of noise. When I export the photo to JPEG (and TIFF/PSD, 16 bit) I get a strange square grid like pattern on the photo.
Here is an example of the ...
2
votes
2answers
3k views
Why is there so much noise in RAW files from my new Canon 7D?
I recently bought a Canon 7D, upgrading from a 50D. I was blown away by what I saw on the back of the camera after I took a few shots.
Now that i've taken the time to import the photos into ...
2
votes
2answers
96 views
Which is the factor that creates noise in a photo? [duplicate]
Possible Duplicate:
What is noise in a digital photograph?
This happens while talking photos on dark or night. The Black color is not black, it has some noise. What would be the reason for ...
2
votes
3answers
1k views
Noise Issue / Canon 5D Mark II
Just curious if anyone can help with this?
I am using a Canon 5D Mark II and it seams to be having noise issues at ISO 250 and up and especially at ISO 400? What is going on?
In low light when my ...
2
votes
2answers
166 views
Is there software for detecting noisy areas in a photograph?
I have been told that this photograph contains noise and is muddy. It is difficult for me to identify noise in a photograph until it is in extremes.
Are there any softwares available which detect the ...
2
votes
1answer
186 views
Factors for preventing noise in-camera
In low lighting conditions I have to bring up my ISO (even when using flash) and open the aperture to a certain point to get the ambient light alongside subjects I'm photographing (which are mostly ...
2
votes
1answer
343 views
What algorithms or example tools are there for denoising of images in Raw format?
I am trying to perform some post-processing of Camera Raw images captrued using my Canon EOS 450-D. I am using PS CS5 and GIMP particulary to remove noise which is present in images.
My questions is:
...
2
votes
1answer
187 views
Do cameras turn off their sensors when entering the menu?
Let me clarify this: In movie mode (or live view), the sensor is gathering light all the time, and due to this the heat starts to build up.
This is a problem in certain situations, due to the heat ...
1
vote
3answers
280 views
Why is there too much noise in a fog photograph?
I have been told that this photo has terrible noise.
I wasn't aware of this fact! :redface:
Morning scene, F4.8, Shutter: 1/50, ISO 100, Focal 14.4mm.
The fog was dense of course, but still it ...
1
vote
6answers
569 views
Is noise related to shutter speed as well as ISO?
I understand that as I increase ISO, I'll increase the amount of noise in the resulting image. With a constant aperture I can decrease ISO and slow the shutter speed (assume a non-moving subject, ...
1
vote
2answers
806 views
What is the source of excessive noise in images from my D7000?
I'm a beginning photographer who recently invested in the following setup:
Nikon D7000 camera body, 15-105mm Nikor kit lens, 150-500mm Sigma lens.
We recently made a trip to the Pantanal, Brazil ...
1
vote
2answers
112 views
Does shooting at lower MP result in less image noise? [duplicate]
My Sony a65 has a 24MP and 10MP mode. Will shooting at 10MP result in less image noise? I'm looking to do more night photography.
1
vote
4answers
177 views
How do I reduce the noise in this image / prevent noise in future images?
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 ...
