What is ISO?!

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camway

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Simply wondering what is ISO and the outcome of the photo depending on the levels and also wondering how to adjust the levels on a Canon 600D? I usually shoot on the automatic modes of either sport or portrait on my camera so I was also wondering on any other tips for more manual operation to enhance my photos and the effects that they would have
 

yorgdevelopment

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ISO is your camera's sensitivity to light. Low ISO does well in high light conditions, high ISO does well in low light conditions. A tip to learn manual precision is to experiment, depending on the type of learner you are, you may benefit from such a hands on learning experience. You can easily orient yourself to the functions of your camera by checking out books from your local library or signing up for classes at a community college. There is no brief explanation of how to use a camera, nor is there a right or wrong way to shoot a photo. Good luck.
 

412 Burgh

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Quick fun fact!

ISO doesn't stand for anything related to it's meaning lol. ISO = International Standards Organization.
 

SCraig

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Take a look at the turorials Here.

ISO as it relates to digital cameras is the level of the sensitivity of the sensor. The more sensitive the sensor is the more it will amplify low-level signals. This includes the low-level signals within the circuitry of the camera itself which then shows up in the images as digital "Noise".

ISO is also one side of the "Exposure Triangle", the other two being shutter speed and aperture. Always try to use the lowest ISO that will still allow the shutter speed and aperture that you want to use.
 

TCampbell

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Simply wondering what is ISO and the outcome of the photo depending on the levels and also wondering how to adjust the levels on a Canon 600D? I usually shoot on the automatic modes of either sport or portrait on my camera so I was also wondering on any other tips for more manual operation to enhance my photos and the effects that they would have

You've got me curious. It seems a bit odd that someone happily using the automatic scene modes would suddenly ask about ISO and how to adjust it... without knowing what it is. Were you having a problem with your image quality? Did someone suggest you adjust the camera's ISO sensitivity?

It's possible we could give specific guidance if we knew why you were asking.

Image quality will degrade as you increase the camera's ISO sensitivity. At first you get tiny amounts of "noise" in the image -- often not enough to notice. But as you continue to increase the ISO, the noise will eventually get so bad that you would probably decide the image quality is unacceptable. For this reason we tend to prefer to keep ISO settings low whenever there's enough light that high ISO isn't necessary. However... if you keep the ISO settings low all the time, you'll eventually encounter situations where it's just too dark to take a photo without using long shutter exposures... and those will be blurry if the camera is hand-held (nobody can be "perfectly" steady.)

The size of the clear area in the lens through which the light may pass is the "aperture" and is controlled by adjusting the "f-stop". The shutter speed controls how long the shutter will remain open when taking a photo. And the ISO will determine how sensitive the camera sensor will be to the light. Together these three factors control the exposure.

I would suggest you pick up a copy of "Understanding Exposure" (by Bryan Peterson) -- a great book for beginners learning to shoot with a DSLR camera.
 

Big Mike

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Another way to think about it: The ISO setting on your camera, is very similar to the volume setting on your stereo. It takes an input signal and amplifies it...giving you a higher output.
On your stereo, as you turn up the volume, you get a louder output from the speakers. On your camera, as you turn up the ISO, you get a brighter image (if other settings remain the same).

Now think about what happens when you turn your volume up to 10. You will likely hear buzzing, popping, crackling....distortion. The same thing happens with your camera, but instead of audible noise, you get 'digital noise'. In other words, the higher the ISO, the more distortion you will get, and thus the image quality is said to get worse.
 

MyEyeCreative

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ISO is an extremely important part of photography. It controls how sensitive your lense is to light, by lowering your ISO it makes your camera less sensitive to light making it ideal for bright light settings while setting it higher will be more ideal for dimly lit settings because your camera is much more sensitive to the light reflecting onto it. Shooting in a location with constant sun I would recommend setting your ISO the the lowest number possible. This will allow you to require the most realistic image possible. If you are night shooting with next to no light I would recommend shooting no more than around 6400 even at that it will accumulate much more noise in your photo than if you were using an ISO setting of for say 100. These are just tips from my personal experience to find the right settings for you go outside and start experimenting with your camera. See what setting you can achieve before hitting an absurd amount of noise. Have fun and experience life, use these tips as guidelines more than rules!
 
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Ysarex

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ISO is an extremely important part of photography. It controls how sensitive your lense is to light, by lowering your ISO it makes your camera less sensitive to light making it ideal for bright light settings while setting it higher will be more ideal for dimly lit settings because your camera is much more sensitive to the light reflecting onto it. Shooting in a location with constant sun I would recommend setting your ISO the the lowest number possible. This will allow you to require the most realistic image possible. If you are night shooting with next to no light I would recommend shooting no more than around 6400 even at that it will accumulate much more noise in your photo than if you were using an ISO setting of for say 100. These are just tips from my personal experience to find the right settings for you go outside and start experimenting with your camera. See what setting you can achieve before hitting an absurd amount of noise. Have fun and experience life, use these tips as guidelines more than rules! myeyecreative.weebly.com

Welcome to TPF.

You've dragged up an old dead thread from 4 years ago? Consider joining the discussions currently in progress.

The information you've presented here is just wrong. ISO does not control the light sensitivity of your camera. See this thread: Want a better understanding of ISO?

Joe
 

table1349

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ISO is an extremely important part of photography. It controls how sensitive your lense is to light, by lowering your ISO it makes your camera less sensitive to light making it ideal for bright light settings while setting it higher will be more ideal for dimly lit settings because your camera is much more sensitive to the light reflecting onto it. Shooting in a location with constant sun I would recommend setting your ISO the the lowest number possible. This will allow you to require the most realistic image possible. If you are night shooting with next to no light I would recommend shooting no more than around 6400 even at that it will accumulate much more noise in your photo than if you were using an ISO setting of for say 100. These are just tips from my personal experience to find the right settings for you go outside and start experimenting with your camera. See what setting you can achieve before hitting an absurd amount of noise. Have fun and experience life, use these tips as guidelines more than rules! myeyecreative.weebly.com
ISO has nothing to do with lens sensitivity to light, neither now or back in 2013. Lenses don't have sensitivity to light. Here is the actual relationship of ISO in the digital world. ISO sensitivity | DxOMark
www.Clarkvision.com: ISO and Digital Cameras, ISO Myths

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fmw

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International Standards Organization. Decades ago "film speed" or the film's sensitivity to light was defined by the American Standards Association or ASA. So the photographer could expect a film rated at 200 ASA to require one stop less exposure than one rated 100 ASA. The standards were moved to the ISO for whatever reason and the same ratings became 200 ISO etc.

The downside to a high ASA or ISO rating was grain because faster films performed as they did by creating larger clumps of silver on the film. The higher the rating, the grainier the image the film would produce.

When we moved from film to digital, film speed was no longer an issue. But since digital sensors have adjustable sensitivity, it was common sense to move those same ISO film ratings to the digital sensor. So the system was set up to copy the results a photographer could expect from the old ISO film rating to the new ISO digital sensor rating. A photographer dialing in ISO 200 into his digital camera can expect the same exposure performance as he or she did with ISO 200 film.

Digital photography doesn't involve clumps of silver but there are similar issues with the use of higher ISO settings. We call those issues digital noise and you can find examples of it on the internet. Higher ISO settings create more digital noise. It is comparable to what we did in the old days by selecting our film.
 

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International Standards Organization.

It's actually the International Organization for Standardization.

Decades ago "film speed" or the film's sensitivity to light was defined by the American Standards Association or ASA. So the photographer could expect a film rated at 200 ASA to require one stop less exposure than one rated 100 ASA. The standards were moved to the ISO for whatever reason and the same ratings became 200 ISO etc.

The downside to a high ASA or ISO rating was grain because faster films performed as they did by creating larger clumps of silver on the film. The higher the rating, the grainier the image the film would produce.

When we moved from film to digital, film speed was no longer an issue. But since digital sensors have adjustable sensitivity,

They don't. The light sensitivity of a digital sensor is fixed when manufactured and can not be altered in any way.

it was common sense to move those same ISO film ratings to the digital sensor. So the system was set up to copy the results a photographer could expect from the old ISO film rating to the new ISO digital sensor rating. A photographer dialing in ISO 200 into his digital camera can expect the same exposure performance as he or she did with ISO 200 film.

Digital photography doesn't involve clumps of silver but there are similar issues with the use of higher ISO settings. We call those issues digital noise and you can find examples of it on the internet. Higher ISO settings create more digital noise.

That's a spurious correlation. Digital noise is primarily a function of exposure. To the extent that most people use the camera ISO setting to alter exposure noise increase correlates with ISO increase. However, the post exposure function of ISO in a digital camera reduces noise.

Joe

It is comparable to what we did in the old days by selecting our film.
 

fmw

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International Standards Organization.

It's actually the International Organization for Standardization.

Decades ago "film speed" or the film's sensitivity to light was defined by the American Standards Association or ASA. So the photographer could expect a film rated at 200 ASA to require one stop less exposure than one rated 100 ASA. The standards were moved to the ISO for whatever reason and the same ratings became 200 ISO etc.

The downside to a high ASA or ISO rating was grain because faster films performed as they did by creating larger clumps of silver on the film. The higher the rating, the grainier the image the film would produce.

When we moved from film to digital, film speed was no longer an issue. But since digital sensors have adjustable sensitivity,

They don't. The light sensitivity of a digital sensor is fixed when manufactured and can not be altered in any way.

it was common sense to move those same ISO film ratings to the digital sensor. So the system was set up to copy the results a photographer could expect from the old ISO film rating to the new ISO digital sensor rating. A photographer dialing in ISO 200 into his digital camera can expect the same exposure performance as he or she did with ISO 200 film.

Digital photography doesn't involve clumps of silver but there are similar issues with the use of higher ISO settings. We call those issues digital noise and you can find examples of it on the internet. Higher ISO settings create more digital noise.

That's a spurious correlation. Digital noise is primarily a function of exposure. To the extent that most people use the camera ISO setting to alter exposure noise increase correlates with ISO increase. However, the post exposure function of ISO in a digital camera reduces noise.

Joe

It is comparable to what we did in the old days by selecting our film.

Sometimes the post process can increase digital noise. IOS is the European name for it. ISO is the English one. Both terms say the same thing. Digital noise is all about the ISO setting. One can make two exposures to produce the same EV with different ISO settings and get different amounts of digital noise. I'll stand by what I wrote.
 

Ysarex

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International Standards Organization.

It's actually the International Organization for Standardization.

Decades ago "film speed" or the film's sensitivity to light was defined by the American Standards Association or ASA. So the photographer could expect a film rated at 200 ASA to require one stop less exposure than one rated 100 ASA. The standards were moved to the ISO for whatever reason and the same ratings became 200 ISO etc.

The downside to a high ASA or ISO rating was grain because faster films performed as they did by creating larger clumps of silver on the film. The higher the rating, the grainier the image the film would produce.

When we moved from film to digital, film speed was no longer an issue. But since digital sensors have adjustable sensitivity,

They don't. The light sensitivity of a digital sensor is fixed when manufactured and can not be altered in any way.

it was common sense to move those same ISO film ratings to the digital sensor. So the system was set up to copy the results a photographer could expect from the old ISO film rating to the new ISO digital sensor rating. A photographer dialing in ISO 200 into his digital camera can expect the same exposure performance as he or she did with ISO 200 film.

Digital photography doesn't involve clumps of silver but there are similar issues with the use of higher ISO settings. We call those issues digital noise and you can find examples of it on the internet. Higher ISO settings create more digital noise.

That's a spurious correlation. Digital noise is primarily a function of exposure. To the extent that most people use the camera ISO setting to alter exposure noise increase correlates with ISO increase. However, the post exposure function of ISO in a digital camera reduces noise.

Joe

It is comparable to what we did in the old days by selecting our film.

Sometimes the post process can increase digital noise. IOS is the European name for it. ISO is the English one. Both terms say the same thing.

I wasn't referring to the acronym. I was referring to what the organization calls itself: Home

Digital noise is all about the ISO setting. One can make two exposures to produce the same EV with different ISO settings and get different amounts of digital noise.

Yes, but the result will be opposite of what you claimed. In this case the higher ISO setting will typically reduce noise (depends somewhat on the specific camera) rather than as you claimed; "Higher ISO settings create more digital noise." The dominant source of noise in a digital photo is shot noise which is a function of exposure, not the ISO signal processing. The correlation of increased noise with increased ISO is spurious.

Joe

I'll stand by what I wrote.
 

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Oh Goody, an argument over a 5 year old zombie post.
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