SX10 - Extended TV

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    SX10 - Extended TV
    « on: 20 / October / 2009, 12:06:26 »
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    As posted in  http://chdk.setepontos.com/index.php/topic,4138.0.html, I found that the shutter (TV) overrides were not working for the SX10 and found the solution.

    The apex2us function in generic/wrappers.c should be modified as follows:
    Code: [Select]
    int  apex2us(int apex_tv){
    #if CAM_EXT_TV_RANGE
     short tv;
     tv = shooting_get_tv96();
     if (tv<-576 || tv!=apex_tv) return 1000000.0*pow(2.0, -tv/96.0);
     else return _apex2us(apex_tv);
    #else
     return 0;
    #endif
    }

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    Offline fe50

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    Re: SX10 - Extended TV
    « Reply #1 on: 20 / October / 2009, 16:50:34 »
    Congratulations, good work !

    Did a fast test with my personal build, your code works fine !
    I'll do some more test the next days, also with your extended Av code...


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    Offline RaduP

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    Re: SX10 - Extended TV
    « Reply #2 on: 20 / October / 2009, 23:52:53 »
    Great, it works on my SD980 too.
    I was testing it with a fluorescent lamp, but I guess that's not a very reliable way, because the light depends on the voltage which fluctuates 50 times a second. I guess I should use an LED.

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    Offline fe50

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    Re: SX10 - Extended TV
    « Reply #3 on: 21 / October / 2009, 01:28:35 »
    Great, it works on my SD980 too.
    I was testing it with a fluorescent lamp, but I guess that's not a very reliable way, because the light depends on the voltage which fluctuates 50 times a second. I guess I should use an LED.

    I guess most SX10-based ports are affected by this...
    ...use an "old style" 100W bulb (or a halide lamp) and take nice shoots from the glowing filament - without using a dimmer  8)


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    Offline RaduP

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    Re: SX10 - Extended TV
    « Reply #4 on: 21 / October / 2009, 01:53:35 »
    The lightbulb is still somewhat affected by the alternative current though.
    BTW, why do the cameras based on the SX10 port have this problem? Something wrong with the SX10 port?

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    Offline reyalp

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    Re: SX10 - Extended TV
    « Reply #5 on: 21 / October / 2009, 02:03:14 »
    The lightbulb is still somewhat affected by the alternative current though.
    BTW, why do the cameras based on the SX10 port have this problem? Something wrong with the SX10 port?
    Read the thread. [spoiler]The canon code has changed[/spoiler].
    Don't forget what the H stands for.

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    Offline RaduP

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    Re: SX10 - Extended TV
    « Reply #6 on: 21 / October / 2009, 02:15:08 »
    Read the thread. [spoiler]The canon code has changed[/spoiler].

    obviously. But there are some differences between ports as well, and that could cause some problems.

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    Offline reyalp

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    Re: SX10 - Extended TV
    « Reply #7 on: 21 / October / 2009, 03:09:13 »
    obviously. But there are some differences between ports as well, and that could cause some problems.
    Could cause all kinds of problems, but not this one, as far as I can tell. If you think different, please
    1) read and understand the code in questions
    2) point out the specific difference you think is relevant to this problem
    Don't forget what the H stands for.


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    Offline RaduP

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    Re: SX10 - Extended TV
    « Reply #8 on: 21 / October / 2009, 03:45:49 »
    I am not saying that I think this is the problem, I was just confused by fe50's statement that the SX10 based ports have this problem.
    One of the possible problems could be the way different tasks are hacked, such as the exact placement of modified code in the hijacked tasks. While it probably does not affect this particular issue, I did notice differences in the SD990 vs sx10 on how and where the keyboard is hooked, or the init code in boot.c

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    Re: SX10 - Extended TV
    « Reply #9 on: 21 / October / 2009, 10:07:33 »
    Great, it works on my SD980 too.
    I was testing it with a fluorescent lamp, but I guess that's not a very reliable way, because the light depends on the voltage which fluctuates 50 times a second. I guess I should use an LED.

    Did the SD980 have this problem as well?

    Testing with flourescent or incandescent lamps should be OK in the general sense even though the voltage (and brightness) technically fluctuates, however they tend not to be "instant" on/off.  You should still be able to see a positive exposure difference at least with a couple test runs.  You should at least be able to 'see' a difference, I just wouldn't rely on comparing actual exposure values calculated from an image (i.e. trust the presence of an exposure change, but not the magnitude).

    LEDs would be good if they are bright enough and DC driven.  AC driven LEDs and arrays have an even worse flicker effect than incandescent or flourescent as they are virtually "instant" on/off.

    [rant]
    As a side note I really hate those LED chrismas lights and new LED brake lights you are seeing everywhere, as I can't detect the flicker espescially when in the peripheral vision range.  They need to find a cheap way make them continuous driven (ie 3-phase or maybe a bias flow) In the very least they could alternate LED phases within the array, but I suppose this would require 2 circuits rather than just one.
    [/rant]

     

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