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Thread: EV calculator to iPhone 3GS

  1. #1
    Antonio Correia's Avatar
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    EV calculator to iPhone 3GS

    I would like to have an EV calculator in my iPhone and - having Googled a bit - I found this one which looks good enough.

    However, I don't want to buy any app until I get some advice from you.

    Any tips please ?

    Thank you

  2. #2

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    Re: EV calculator to iPhone 3GS

    Quote Originally Posted by Antonio Correia View Post

    Any tips please ?
    Yes -- open your wallet and take a chance Scrooge - it's only 1 US Dollar!

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    Antonio Correia's Avatar
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    Re: EV calculator to iPhone 3GS

    Quote Originally Posted by Colin Southern View Post
    Yes -- open your wallet and take a chance Scrooge - it's only 1 US Dollar!
    Excuse me Colin but I couldn't find that app despite of having searched in different ways.

    I must be doing something wrong.

    Oh I understand now... You are pulling my leg...

    scrooge app for iphone

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    Re: EV calculator to iPhone 3GS

    Wrong scrooge ... you need this one ...

    http://en.wikipedia.org/wiki/Ebenezer_Scrooge



    PS: What's wrong with using the "EV App" built right into you camera (called "Metering")?

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    Antonio Correia's Avatar
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    Re: EV calculator to iPhone 3GS

    Nothing is wrong with the built in system for measuring the light.
    I want to use this calculator for scenes under Moon Light when the exposure is larger than 30". The calculator will allow me to expose correctly under any circumstances based on the camera system itself.
    Yesterday at the main place of Setubal I wanted to shoot with the closest possible aperture and low ISO and the camera was refusing to measure over 30"
    BTW Olympus goes until 40"
    With the calculator I can do it securely without forgetting how a timer is great at this time. Sure. Also a tripod
    I will be able to do the same in the field under the Moon light one of these days...

    Meanwhile one app I found.
    And another one

    EV calculator to iPhone 3GS


    Believe it or not I read Oliver Twist when I was young. In Portuguese.
    Last edited by Antonio Correia; 7th July 2010 at 12:32 PM.

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    Re: EV calculator to iPhone 3GS

    Quote Originally Posted by Antonio Correia View Post
    Nothing is wrong with the built in system for measuring the light.
    I want to use this calculator for scenes under Moon Light when the exposure is larger than 30". The calculator will allow me to expose correctly under any circumstances based on the camera system itself.
    Yesterday at the main place of Setubal I wanted to shoot with the closest possible aperture and low ISO and the camera was refusing to measure over 30"
    Hi Antonio,

    Just temporarily increase the ISO until you get a reading under 30 seconds, and then double the exposure for each ISO stop you decrease back to your base ISO. So if you have to go to 400 ISO to get a reading and that reading is 25 seconds then that will be the same as 50 seconds @ 200 ISO or 100 seconds @ 100 ISO. You'll need to find a way to manually time the exposure in bulb mode though, as you can't set an exposure greater than 30 seconds in manual mode (I use a TC 80-N3 to time my bulb exposures).

    Hope this helps

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    Re: EV calculator to iPhone 3GS

    Quote Originally Posted by Antonio Correia View Post
    Meanwhile one app I found.
    And another one
    Hi Antonio,

    If I had an iPhone, I'd pay the 99c (for the first one at least), just to put you out of your misery/dilema

    For that price, wouldn't it be more cost effective time-wise, for you just to buy it, try it and see?

    Cheers,

  8. #8
    Antonio Correia's Avatar
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    Re: EV calculator to iPhone 3GS

    Quote Originally Posted by Colin Southern View Post
    Hi Antonio,

    Just temporarily increase the ISO until you get a reading under 30 seconds, and then double the exposure for each ISO stop you decrease back to your base ISO. So if you have to go to 400 ISO to get a reading and that reading is 25 seconds then that will be the same as 50 seconds @ 200 ISO or 100 seconds @ 100 ISO. You'll need to find a way to manually time the exposure in bulb mode though, as you can't set an exposure greater than 30 seconds in manual mode (I use a TC 80-N3 to time my bulb exposures). Hope this helps
    Yes that is fine. I'll try that procedure. Thank you
    I don't have the TC80N3 but the lower version... the RS80N3
    -
    Quote Originally Posted by Dave Humphries View Post
    Hi Antonio, If I had an iPhone, I'd pay the 99c (for the first one at least), just to put you out of your misery/dilema For that price, wouldn't it be more cost effective time-wise, for you just to buy it, try it and see? Cheers,
    Good and wise advice

  9. #9
    Antonio Correia's Avatar
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    EV calculator table

    Let's see if I can explain myself in what I was expecting from an app of these.

    When I shoot during the night in poor light conditions and I want to make loooong exposures I find that my camera stops at 30" as maximum.

    As I want to keep the Exposure Value (EV) correct I am needing a way to calculate it with precision.
    I downloaded two programs from the iTunes and I found them not doing what I wanted.
    Shame: one of them stopped at 30 seconds !
    May be it's just me or my ignorance or... both.
    I understand that it is not practical to have to keep looking among a couple of situations looking for what is supposed to be the right EV.

    Let me give you a quick example:
    I am on the field and I read the light and it goes like this:
    ISO 100 - 15 sec exposure - f/4

    But if I want to use f/11 I must change the other parameters.
    I light my torch on the iPhone because it is dark and take my table from the pocket and read that I have to change the exposure to 2 minutes keeping the ISO

    I was expecting that the apps would help me but just confused me until I decided to build this table. I am only showing you a small part of the table as it is much broader...

    Any corrections ? Am I wrong ? Where ?

    EV calculator to iPhone 3GS

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