Linked Questions

126
votes
7answers
15k 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?
44
votes
10answers
2k views

Should higher ISOs really be preferred (all other things being equal)?

My understanding of the ISO setting on digital cameras is that, unlike film-cameras, changing the ISO does not evoke any physical change in the camera. Rather, it simply tells the camera to multiply ...
7
votes
7answers
3k views

Is there any reason to change the ISO manually?

Here's my understanding so far. When taking a photo with a digital camera, there are some tradeoffs: Aperture size: bigger aperture lets in more light, smaller aperture means less blurring in space. ...
10
votes
3answers
3k 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 ...
3
votes
4answers
539 views

How much of digital sensor noise is thermal?

Is all digital sensor noise thermal? And what is the relationship between temperature and noise? For example, as we cooled a CMOS towards absolute zero, would we discover that high-ISO images would ...
5
votes
2answers
563 views

Does changing the ISO of a modern digital camera really change the gain of an electronic amplifier?

The question Why would using higher ISO and faster shutter speed yield more noise than using lower ISO and slower shutter speed? currently has five answers, and four of them contain the word amplify ...
2
votes
3answers
458 views

Does red noise even at low ISO values mean a hardware problem with my camera's sensor?

I have an Canon 200D (Rebel SL). I am concerned about the red noise in the darker parts of the picture, at low ISO values. Especially in the blue sky. Could this be a hardware problem with a sensor? ...
-2
votes
2answers
519 views

How does a photographer edit to get a photo to look this clean? [closed]

I saw this pic recently and I love to quality and sharpness but I have no idea how one edits to get such a look. I know the photographer used A Nikon D750 and a Nikon 24-70 Here's a second example. ...
2
votes
6answers
185 views

What is the physical cause of increasing noise at high ISO?

Which is the physical cause of the increasing noise at high iso? I know that Iso represents the sensor/film sensitivity to light: at lower iso we need an higher exposure time to get the image of the ...
1
vote
7answers
439 views

How do I know which combination of aperture and shutter speed yields enough light to have pictures with minimal noise?

This is a kind of continuation of this question. I'm shooting a poorly lit object. Camera has fastest ISO value of 3200. I set aperture to some specific value and don't alter it, the object is ...
1
vote
6answers
240 views

What setting should I adjust when using a tripod to get less noise?

If there's a really grainy photo. Not much natural light here and a tripod was available. What should be changed in settings to decrease the noise in the photo? Settings Focal length 12mm ISO 6400 ...
0
votes
2answers
264 views

Why do different ISO images have different file sizes? [duplicate]

I set the ISO on my Canon 6D to 200: 1081 estimated shots remaining. I set the ISO to "auto": 728 estimated shots remaining. I'm shooting in RAW, if that makes a difference.
1
vote
1answer
159 views

Why is same image exposed at 100 ISO noisier than 3200 ISO? [duplicate]

I used to believe that ISO adds noise as a drawback to increasing exposure, but after researching the topic I arrived at the conclusion that it is a misconception. By amplifying the existing signal ...