Definition of ISO 100,200 and 400?


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Mankul

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#1
errr :p ISO 100, ISO 200 and ISO 400 sensitivity level..


what is the definition... my canon S10 both have manual shuttle speed control... so ISO 100, ISO 200 and ISO 400 represents what shuttle speed?

thanks!
 

ckiang

Senior Member
#2
Originally posted by Mankul
errr :p ISO 100, ISO 200 and ISO 400 sensitivity level..


what is the definition... my canon S10 both have manual shuttle speed control... so ISO 100, ISO 200 and ISO 400 represents what shuttle speed?

thanks!
ISO is not shutter (not shuttle) speed. It is a way of representing the equivalent film sensitivity (film speed) in a digital cameras. A higher ISO film/setting is more sensitive to light, allowing you to take pictures in dimmer situations without flash.

More here:
http://www.dpreview.com/learn/Glossary/Digital_Imaging/Sensitivity_01.htm

Regards
CK
 

Mankul

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#3
Originally posted by ckiang


ISO is not shutter (not shuttle) speed. It is a way of representing the equivalent film sensitivity (film speed) in a digital cameras. A higher ISO film/setting is more sensitive to light, allowing you to take pictures in dimmer situations without flash.

More here:
http://www.dpreview.com/learn/Glossary/Digital_Imaging/Sensitivity_01.htm

Regards
CK
errr...can I say that for low light... I choose ISO400 and for bright light conditions I choose ISO100?
 

ckiang

Senior Member
#4
Originally posted by Mankul


errr...can I say that for low light... I choose ISO400 and for bright light conditions I choose ISO100?
Right. But the other thing is to use the lowest possible ISO. Using high ISO in consumer digital cameras can lead to pictures with a lot of noise.

Regards
CK
 

Klause

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#5
High ISO = Faster Shuttle = More Noise
Low ISO = Slow Shuttle = Little Noise

If you got a tripod, set to the lowest ISO for the best effect. If you are using handheld, and shoots at night, then use high ISO to get faster shuttle.
 

Mankul

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#6
Originally posted by Klause
High ISO = Faster Shuttle = More Noise
Low ISO = Slow Shuttle = Little Noise

If you got a tripod, set to the lowest ISO for the best effect. If you are using handheld, and shoots at night, then use high ISO to get faster shuttle.
ok you got me confused now...
so
high IS0 means ISO400
low ISO means ISO100 for my camera right?!!!

I thought might shots use ISO400... so ISO 400 is relatively high or low ISO compared to ISO100? Which one higher, which one lower?:what:
 

Tweek

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Mankul, it's best that u try out the results since you have a digicam! Take ckiang and klause's replies as reference, take pics in the different ISO settings at different scenes, and take note of the aperture and shutter settings that the camera meters. Also take note of the noise level for each ISO setting. After that, you should have a good understanding of what ISO is all about already. :)
 

Flare

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#8
Ok... I'm here to add to the confusion hahahah~

In addition to all those said... ISO 200 will require half the amount of light to achieve the same exposure compared to ISO 100... and ISO 400 will require half the amount of light to achieve the same exposure as compared to ISO 200.

So, when do you reach for that ISO button? Generally, use ISO100, this gives better image quality, less noise (Random nonsense pixels). Let's say you are indoors or the sun is setting... you pull out your camera, measure the exposure, and Oh god.... You need 1/10 seconds to achieve the correct exposure even though your aperture is set to the widest... and you don't want the flash to throw out the ambient light or for some other reason. And you didn't bother to bring that clumsy tripod or there's no space/time to set it up. So, reach for the ISO switch, switch it to ISO 200 and the shutter speed magically becomes 1/20 seconds, which may not be the best to hand hold but better than 1/10... But darn... due to the lack of breakfast... you are shaking like a drench cat... pump the ISO to 400 and you only need 1/40 seconds~ Nice~ Snap away~

With a higher ISO, you may not get the best picture, but you don't lose the picture(s)!
 

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