What Is ISO?


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funkguru

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Oct 14, 2005
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rivervalley
#1
Hi there everyone,
I'm newbie with a nikon cp 8800, still learning more everyday about taking pictures.
I already understand about shutterspeed and aperture but I catch no ball when it comes to the ISO part.
So I normally leave it on auto. Can someone pls share with me in layman's term the concept of it?:embrass:
 

jbma

Senior Member
Dec 28, 2003
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Tampines
#3
Do more reading dude. Do a google search and wallah.
 

DarkForce

Senior Member
May 1, 2004
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newbie land
#4
;)

http://flfl.essortment.com/buyingcamerafi_rikq.htm

ISO = film speed.

For instance , let say you are using constant shuttle speed S and constant aperture A,

if S + A on ISO 100 take 1 seconds to achieve a certain EV

then using the same S + A on ISO 200 will take about 0.5 seconds to achieve the same EV.

Thus ISO 200 is twice faster to absorb light than ISO 100.
 

Joel Lyn

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Apr 18, 2005
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Bishan
#6
but using higher ISO in nights shots will produce grainer pictures as compared to a lower ISO...
 

jtean

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Oct 11, 2005
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#7
Joel Lyn said:
but using higher ISO in nights shots will produce grainer pictures as compared to a lower ISO...
hi there, what you mean by a grainer pic?
 

Hoky

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Mar 17, 2004
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hoky.multiply.com
#8
jtean said:
hi there, what you mean by a grainer pic?
Higher ISO = Grainy Pic (meaning more noise)

Moreover, it is not unique only to night shots, day shots of high ISO will result in noise.
Longer exposure will also result in more noise also.
 

kensh09

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Feb 1, 2005
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#9
Can say ISO is the sensitivity of the film/sensor to light. Higher ISO means able to take photos in low light condition using faster shutter speed.
 

jtean

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Oct 11, 2005
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#10
Hoky said:
Higher ISO = Grainy Pic (meaning more noise)

Moreover, it is not unique only to night shots, day shots of high ISO will result in noise.
Longer exposure will also result in more noise also.
which means to say that it is thru experience that we are able to determine which is the best ISO settings to go for?
 

Jun 20, 2003
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Visit site
#11
i find it best to stick with lowest iso if can afford like during bright day light.
If at night or inside a concert with lowlight setting but still need to use higher shutter speed, then no choice have to tune up the iso level.
 

ziploc

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Jan 17, 2002
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#12
jtean said:
which means to say that it is thru experience that we are able to determine which is the best ISO settings to go for?
Hi jtean,

Unless you're shooting film which require you to plan the film speed ahead, on digital cameras it is easy to select the ISO. So, depends on the aperture/shutter speed you need, select the lowest ISO that you can go with and change it as necessary. Even film ISO can be changed (with mid roll rewind and film extractor), just a little more tedious. The reason of going with lowest ISO as far as possible is because that will give you the least grain/noise. :)
 

jtean

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Oct 11, 2005
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#13
ziploc said:
Hi jtean,

Unless you're shooting film which require you to plan the film speed ahead, on digital cameras it is easy to select the ISO. So, depends on the aperture/shutter speed you need, select the lowest ISO that you can go with and change it as necessary. Even film ISO can be changed (with mid roll rewind and film extractor), just a little more tedious. The reason of going with lowest ISO as far as possible is because that will give you the least grain/noise. :)
Is there an 'idiot guide' for the control of ISO? newbie needing help. cheers!
 

Hoky

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Mar 17, 2004
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#14
green_leaf said:
i find it best to stick with lowest iso if can afford like during bright day light.
If at night or inside a concert with lowlight setting but still need to use higher shutter speed, then no choice have to tune up the iso level.
Low ISO is the best for P&S and 'easy to use' prosumers at most 'bright' times.
For night shots, shutter speed and exposure is key. ISO depends... on the subject or lighting movement (static, dynamic)

But when you have lot of controls over parameters such as shutter speed, aperture, exposure... etc which limits the amount of light, the user has to determine the required ISO settings for the right shot. :sweatsm:
 

Joel Lyn

New Member
Apr 18, 2005
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Bishan
#15
ok ok... info overload for him le la... poor guy... just keep the ISO to the lowes for bright day shots..

nights shots later la..
 

Hoky

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Mar 17, 2004
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#16
jtean said:
Is there an 'idiot guide' for the control of ISO? newbie needing help. cheers!
Not sure if there's a guide somewhere out there.
But the noise output at the same ISO differ for each camera systems.

For e.g.
My digital Ixus produce noisy pictures at ISO 400, whereas my EOS 350D is acceptable at the same ISO.

Moreover every camera has different ISO setting range, so it is difficult to tell which ISO is suitable and applicable for you.

You will have to try and understand your camera system; the strengths and it's limitations so that you can set appropriate shot settings everytime.
 

jtean

New Member
Oct 11, 2005
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#18
somebody help me!!! haha. think i have to meddle with my Canon S2 first. been 'fooling' around with a low spec d.cam for quite a while. Eversince I'm introduce to this forum. GOSH! Pics starts flowing in. Cheers to all the 'lau jias' in here!
 

Joel Lyn

New Member
Apr 18, 2005
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Bishan
#19
but i am drooling t his cp 8800....

:cry: i got no camera at the moment... urgh...
 

ricohflex

Senior Member
Feb 24, 2005
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#20
ISO
is
International Standards Organisation

Formerly film speed was expressed in ASA
American Standards Association

and

DIN

Deutsche Industire Norm.....something. sorry do not know German

The ASA speed rating was given the "ISO" name later.

ASA 100 would be ISO 100 and would be DIN 21
 

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