Are ISO and Shutter Speed related linerally? - General Chat - CHDK Forum

Are ISO and Shutter Speed related linerally?

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Are ISO and Shutter Speed related linerally?
« on: 31 / December / 2011, 11:03:15 »
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Basically my question is, will I get the same picture if I shot a 60 second exposure at 100ISO as I would if I shot 15 seconds with 400ISO? Is the differential between ISO and shutter speed linear?

Re: Are ISO and Shutter Speed related linerally?
« Reply #1 on: 31 / December / 2011, 12:17:00 »
Is the differential between ISO and shutter speed linear?

Over a certain range .. yes.

It will not apply at very short or very long exposures.

Whether 60 seconds counts as a long exposure I have no idea.

I assume by now you have had the opportunity to test it many times.

microfunguy hits 3000 !!
« Reply #2 on: 31 / December / 2011, 12:21:29 »
Over a certain range .. yes.
Congratulations to microfunguy on his 3000th post !

« Last Edit: 31 / December / 2011, 12:23:38 by waterwingz »
Ported :   A1200    SD940   G10    Powershot N    G16

Re: Are ISO and Shutter Speed related linerally?
« Reply #3 on: 31 / December / 2011, 12:35:21 »
Congratulations on your 3000th post!! That sure is a lot, its hard to comprehend!

Good to know that they are related linearly. Should be useful for astrophotography.


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Offline reyalp

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Re: Are ISO and Shutter Speed related linerally?
« Reply #4 on: 31 / December / 2011, 13:08:48 »
Good to know that they are related linearly. Should be useful for astrophotography.
You may find this useful http://dougkerr.net/Pumpkin/#APEX
Don't forget what the H stands for.

Re: Are ISO and Shutter Speed related linerally?
« Reply #5 on: 31 / December / 2011, 19:16:42 »

Congratulations to microfunguy on his 3000th post !

I delayed posting until the UK was in 2012, far nicer ending 2011 on 3000 posts rather than 3001 !

This is a good opportunity to say that when GrAnd first introduced CHDK (based on earlier work by the still-unknown VitalyB), I had not done any 'C' programming at all.
I decided if I wanted to apply it to stereo photography I would just have to learn.
Well, I know more than then but am still a novice.
Quite a few years to go yet.
It has been a privilege and a pleasure to study the work of more expert developers and I can think of no better way of learning the language.
Infinitely better than endless "Hello World"  and "foo-bar" examples.


David

 

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