Absolutely stoopid question...

Montymint

Montymint

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No
But.....

I can;t seem to get my head around iso and why you would need to jack it up?

Can anybody enlighten me to this and hopefully give an example. I shoot at iso 200 most of the time but I would like to know the application of the higher iso ranges.

Thanks and regards

Pete
 
When the light levels drop and you need shutter speed or extra depth of field, or both.
 
In simple terms, higher ISO's will increase the sensitivity of your sensor, allowing you to use faster shutter speeds in low light. The downside is that this can introduce more noise to your photos depending on the capabilities of your camera.

On a normal day in daylight conditions, there's no real reason to use anything other than ISO100 unless you specifically want to introduce noise.
 
Hi Pete, Iso is the sensitivity of your sensor.

Now in the old days of film, you used to have to make a choice as to which film to load depending on the conditions. Some films had more of the grains which were also smaller per square inch. That was your film speed, 50 or 100 for nice bright stuff right through to 1600 and 3200 for shooting in a crypt!

ISO works pretty much the same way, it's the electronic equivalent. The higher it goes the more sensitive to light your sensor becomes and so it captures more of it.

So if you find yourself in a low light situation, make your sensor more sensitive to any light there is.

Does that help?
 
iso is usually increased because of low light. If you've chosen a specific aperture and the shutter speed required is too low every time you increase iso you will increase your shutter speed.

1/80 at iso 100
1/160 at iso 200
1/320 at iso 400
1/640 at iso 800 etc.

Scott


( I really need to type quicker)
 
Montymint said:
yeah that makes sense, so it's essentially to stop you needing stupidly long exposures when shooting in dark areas?
Click to expand...

Yep, it means you can keep the shutter speed in the realm of unstupid. Take shooting in a church, anything under 1/60 sec is likely to cause problems as people move (highly inconsiderate I know ;)) So I need to keep the shutter speed above 1/60. If I have the lens open at f2.8 anyway, I can't simply change the aperture, so ISO is the one to change upwards.
 
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