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Canon PowerShot A1200

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Offline srsa_4c

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    Re: Canon PowerShot A1200
    « Reply #130 on: 01 / November / 2013, 17:44:27 »
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    @WW

    Out of curiosity, is everything OK in movie mode on this camera? CHDK on the same generation a3200 needs CAM_HAS_MOVIE_DIGEST_MODE to correctly recognize the recording status (movie_status). I would be surprised if mine would be the only camera with this issue.
    http://chdk.setepontos.com/index.php?topic=7180.msg106795#msg106795

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    Re: Canon PowerShot A1200
    « Reply #131 on: 01 / November / 2013, 17:51:07 »
    Out of curiosity, is everything OK in movie mode on this camera? CHDK on the same generation a3200 needs CAM_HAS_MOVIE_DIGEST_MODE to correctly recognize the recording status (movie_status).
    I don't use movie mode much.  Actually, I don't use it at all on any of my cameras.  But I did notice your post earlier today and it got me wondering.

    When I was updating the MDFB script to Lua,  I tested the movie modes using the A1200 and noticed that some OSD elements would stick on the screen and it was impossible to disable them without turning off the whole OSD ( 1.3.0 allow thats now).   Now I know why.

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    Re: Canon PowerShot A1200
    « Reply #132 on: 04 / March / 2014, 02:49:19 »
    Hi Guys , I have a problem with my CHDK on my A1200 . I Set the shutter speed on (for example) 1/200 and when I want to shoot(half shutter) , the camera shows the shutter speed 1/200 but after 1 second or less it shows the shutter speed the one that it determines itself ( for example 1/15 ) and takes the photo with 1/15s shutter speed . I don't know what to do  :( it just works when I put the camera mode on Long Shutter mode and the only thing I get after taking picture in this mode with ( 1/200 s) is a black screen and black photo  ;)

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    Re: Canon PowerShot A1200
    « Reply #133 on: 04 / March / 2014, 08:22:24 »
    Hi Guys , I have a problem with my CHDK on my A1200 . I Set the shutter speed on (for example) 1/200 and when I want to shoot(half shutter) , the camera shows the shutter speed 1/200 but after 1 second or less it shows the shutter speed the one that it determines itself ( for example 1/15 ) and takes the photo with 1/15s shutter speed . I don't know what to do  :( it just works when I put the camera mode on Long Shutter mode and the only thing I get after taking picture in this mode with ( 1/200 s) is a black screen and black photo  ;)
    Tried this on my A1200. 

    If you go into the Canon menu while the camera is in shooting mode and disable Servo AF then it will hold the CHDK Tv setting.  With Servo AF enabled,  I see the same behavior that you do.

    I'll need to look at why this is so. Off the top of my head it might be something to do with the CHDK code using SET_NOW rather that SET_LATER?  Or the camera internally doing the equivalent of continuous half-presses and clearing the override attempt?


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    Re: Canon PowerShot A1200
    « Reply #134 on: 16 / October / 2014, 07:48:53 »
    Just tested this on my 1.00C Canon A1200, works great.
    Yes, RAW has uncorrected strong barrel distortion on wide angle, yet is has more picture information in those non-cropped areas.

    Also I noticed one strange issue so far, when comparing RAW with camera JPEG. RAW is always shifted right by exactly 20 pixels. So, left 20px column from the jpeg is lost, but there's new "unseen" right column.

    The both pictures is 4000x3000, so I guess, the real matrix is a little larger? How can I take it all, or at least, has exact match with camera jpeg?

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    Re: Canon PowerShot A1200
    « Reply #135 on: 16 / October / 2014, 10:39:23 »
    Also I noticed one strange issue so far, when comparing RAW with camera JPEG. RAW is always shifted right by exactly 20 pixels. So, left 20px column from the jpeg is lost, but there's new "unseen" right column.
    The both pictures is 4000x3000, so I guess, the real matrix is a little larger?
    The RAW image is actually 4104x3048 and it's saved that way.  The DNG image uses the sensor active area of 4072x3030.  When I did this port a couple of years ago, I was pretty careful about how I lined setup the DNG active area but I believe there is some speculation about how precisely the sensor is placed on low end P&S cameras.  I've since acquired another A1200 so I'll go back and take a look at both.

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    How can I take it all, or at least, has exact match with camera jpeg?
    Note that if you are using the 1.3.0 version of CHDK and you are saving DNG rather than RAW (which I assume from your comments you are) then you have a menu option to save the DNG cropped as full sensor size,  active area, or JPG size.  Prior to 1.3.0 you were only able to save the "active area" defined by the person who did the port.



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    Re: Canon PowerShot A1200
    « Reply #136 on: 18 / October / 2014, 22:28:14 »
    Yes, I was using the 1.2 version since it kind of "stable". And now with 1.3 there's new options with full sensor size and JPG size, thank you for this advice.
    Full sensor isn't very useful, though - the picture has black borders on every side except the left. Guess that's why camera jpeg is almost aligned to the left too.

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    That's most likely because the camera does not have a variable aperature.    The reported f-stop only changes when you move the zoom lens position.  Changing the zoom position changes the effective aperature.
    Well, how the camera can shoot at sunny day then? Just looked to the EXIF, there is f-numbers like 8.3 at wide angle. Yes, f-stop at this sensor size has almost no use, but I still miss any kind of aperture control.

    Also, is it impossible to contol more video option, like shutter speed? Default video looking too jerky.
    Any compact cam makes video like this, no surprises here, but that's "h" in CHDK for. It is almost perfect piece of software for pushing the cheapest camera to the limit.

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    Re: Canon PowerShot A1200
    « Reply #137 on: 18 / October / 2014, 22:52:13 »
    Yes, I was using the 1.2 version since it kind of "stable". And now with 1.3 there's new options with full sensor size and JPG size, thank you for this advice.
    The current 1.3.0 version is very stable - in fact it's about to become the official stable version.  It's just that the CHDK dev community reserves the right to make more changes there.

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    Full sensor isn't very useful, though - the picture has black borders on every side except the left. Guess that's why camera jpeg is  almost aligned to the left too.
    Well, if you want to use RAW / DNG then you get what the sensor gives.  Why is it not useful if parts of the sensor are masked off in your camera and you see that in the image data?  That's what your camera is producing - CHDK can't fix what is not there.  And you are free to crop and adjust to your heart's content in post processing.

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    Well, how the camera can shoot at sunny day then?
    Hmmm ... let me see if I can figure this out?  Faster shutter speed maybe?  Lowest ISO setting?  Or maybe also insert a Neutral Density filter into the light path.   Yup .. that should do it.

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    Just looked to the EXIF, there is f-numbers like 8.3 at wide angle. Yes, f-stop at this sensor size has almost no use, but I still miss any kind of aperture control.
    If you see f8.3 at wide angle that tells you that the camera has inserted its Neutral Density filter into the light patch.

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    Also, is it impossible to contol more video option, like shutter speed? Default video looking too jerky. Any compact cam makes video like this, no surprises here, but that's "h" in CHDK for. It is almost perfect piece of software for pushing the cheapest camera to the limit.
    If you want to push the camera to the limits,  here's the script that does that: http://chdk.wikia.com/wiki/Manual_Exposure_Control_for_Video_Recording
    YMMV but try it out !


     

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