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(noob) G12 cant set EV

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(noob) G12 cant set EV
« on: 28 / July / 2014, 04:53:51 »
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Hi All,

Silly noob question:

I've been trying some of the scripts on the wiki in regards to HDR and none of them seem to actually change any of the settings on my camera.

It will take the correct number of shots but all the photos are (almost) the same.

Apart from loading the script do i need to do anything else to allow the script to change values on my camera?

Cheers

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Offline msl

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Re: (noob) G12 cant set EV
« Reply #1 on: 28 / July / 2014, 06:49:59 »
Which scripts you've tried? Probably there were only scripts for older cameras with wrong propertycases.

Try a script from the CHDK zip file, hdr.bas or hdr.lua. These are Tv bracketing scripts. For a first success are these scripts good enough.

Ev bracketing is a simple task. The following lines make 3 photos, first normal, second -1Ev, third +1Ev.

Code: [Select]
@title ev bracketing

shoot
set_ev -96
shoot
set_ev 96
shoot

Save the lines in a file, e.g. as ev.bas.

msl
German CHDK pages:  CHDK forum | CHDK inside | CHDK Twitter News by msl | Download CHDK-DE (Autobuild)
Note: SDM violates the GPL rules!

Re: (noob) G12 cant set EV
« Reply #2 on: 28 / July / 2014, 07:46:35 »
Hi msl,

Thanks for the reply.

the TV hdr scripts work that come with the CHDK firmware.

With your example, set_ev seems to do nothing. I've tried it in AV mode and Manual mode.

I then added a few "get_ev e" commands after the "set_ev" to see if it was actually setting but the camera says "unknown statement"

Is EV not implemented in CHDK for G12 v1.00e?

Cheers

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Offline msl

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  • A720 IS, SX220 HS 1.01a
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Re: (noob) G12 cant set EV
« Reply #3 on: 28 / July / 2014, 08:19:05 »
Ev settings are available for all cameras. But the mode M is not the best choice. Try the script with the P mode.

For reading the Ev settings you can insert a line in the script like this:
Code: [Select]
print get_ev
For some tests try the next script demo:
Code: [Select]
@title ev test
@param e 1/3 ev steps
@default 0
@range -9 9

set_ev e*32
shoot
print get_ev
Check also the Exif data.

msl
German CHDK pages:  CHDK forum | CHDK inside | CHDK Twitter News by msl | Download CHDK-DE (Autobuild)
Note: SDM violates the GPL rules!


Re: (noob) G12 cant set EV
« Reply #4 on: 28 / July / 2014, 08:57:27 »
I've been trying some of the scripts on the wiki in regards to HDR and none of them seem to actually change any of the settings on my camera. It will take the correct number of shots but all the photos are (almost) the same.
Apart from loading the script do i need to do anything else to allow the script to change values on my camera?
Can you provide a few links to scripts that do not work for you? Also, what version /  release of CHDK are you using? (the complete name of the file you downloaded & installed - or go to the Miscellaneous Stuff menu and click on "Show Build Info")

I then added a few "get_ev e" commands after the "set_ev" to see if it was actually setting but the camera says "unknown statement"
try

Code: [Select]
e=get_ev

Ported :   A1200    SD940   G10    Powershot N    G16

Re: (noob) G12 cant set EV
« Reply #5 on: 28 / July / 2014, 09:14:29 »
Hi,

Here is the code i am trying
Code: [Select]
@title ev bracketing DEBUG

e=get_ev
print "EV = ", e
shoot

set_ev -96
sleep 500
e=get_ev e
print "EV = ", e
shoot

set_ev 96
sleep 500
e=get_ev e
print "EV = ", e
shoot

my output is:
Code: [Select]
EV = 0
EV = -96
EV = 96

my 3 jpg files all look the same and the metadata says:
EV = 0
f = 2.8
ISO = 500
exposure = 1/30 for the first photo and 1/25 for the last two

I also have camera in P mode.

Firmware is g12-100e-1.3.0-3544-full. I also tried latest stable 1.2 which gave same results.

Any ideas? I'm completely lost.

Cheers

Re: (noob) G12 cant set EV
« Reply #6 on: 30 / July / 2014, 00:04:06 »
Here is the code i am trying ....
Ran your code on my A1200 and it did exactly what you expected it would do - three JPG images with three different exposures marked as 0, -1, 1 in the exif data for Ev adjustment.  The CHDK console showed 0, -96 and +96

So I ran the same script on my G10 (very similar camera to your G11) and got the same thing you did :

Quote
my 3 jpg files all look the same and the metadata says:
EV = 0

So there is nothing wrong with your script. 

I'm guessing that Canon P&S cameras with an external Ev offset dial (the G series) do not respond to CHDK's way of setting Ev adjustment values (via propcase setting).

Ported :   A1200    SD940   G10    Powershot N    G16

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Offline philmoz

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Re: (noob) G12 cant set EV
« Reply #7 on: 01 / August / 2014, 18:35:16 »
Here is the code i am trying ....
Ran your code on my A1200 and it did exactly what you expected it would do - three JPG images with three different exposures marked as 0, -1, 1 in the exif data for Ev adjustment.  The CHDK console showed 0, -96 and +96

So I ran the same script on my G10 (very similar camera to your G11) and got the same thing you did :

Quote
my 3 jpg files all look the same and the metadata says:
EV = 0

So there is nothing wrong with your script. 

I'm guessing that Canon P&S cameras with an external Ev offset dial (the G series) do not respond to CHDK's way of setting Ev adjustment values (via propcase setting).

The propcase setting works if it is done after the exposure calculation when the shutter is half pressed. You can verify this by enabling the 'Fast EV switch' option and rotating the jogdial with the shutter half pressed.

The current set_ev() function will probably work in a script if it half presses the shutter, waits for the camera to be ready then calls set_ev() before fully pressing the shutter.

A better approach might be to add an Ev override (like Av, Tv and ISO) to the shooting_expo_param_override() function, and use the SET_NOW/SET_LATER system in the script set_ev() function to control the override.

Phil.
CHDK ports:
  sx30is (1.00c, 1.00h, 1.00l, 1.00n & 1.00p)
  g12 (1.00c, 1.00e, 1.00f & 1.00g)
  sx130is (1.01d & 1.01f)
  ixus310hs (1.00a & 1.01a)
  sx40hs (1.00d, 1.00g & 1.00i)
  g1x (1.00e, 1.00f & 1.00g)


Re: (noob) G12 cant set EV
« Reply #8 on: 01 / August / 2014, 18:51:00 »
A better approach might be to add an Ev override (like Av, Tv and ISO) to the shooting_expo_param_override() function, and use the SET_NOW/SET_LATER system in the script set_ev() function to control the override.
There already is a set_ev() override function but it just pokes the passed value into the appropriate propcases.  Sound like it needs to be modified to support SET_NOW/SET_LATER.
Ported :   A1200    SD940   G10    Powershot N    G16

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Offline philmoz

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    • Photos
Re: (noob) G12 cant set EV
« Reply #9 on: 01 / August / 2014, 19:00:54 »
A better approach might be to add an Ev override (like Av, Tv and ISO) to the shooting_expo_param_override() function, and use the SET_NOW/SET_LATER system in the script set_ev() function to control the override.
There already is a set_ev() override function but it just pokes the passed value into the appropriate propcases.  Sound like it needs to be modified to support SET_NOW/SET_LATER.

The current set_ev() function is only available for scripts - there is no equivalent in shooting.c that is available as an override (e.g. shooting_set_tv96_direct) and can be called from shooting_expo_param_override().

Phil.
CHDK ports:
  sx30is (1.00c, 1.00h, 1.00l, 1.00n & 1.00p)
  g12 (1.00c, 1.00e, 1.00f & 1.00g)
  sx130is (1.01d & 1.01f)
  ixus310hs (1.00a & 1.01a)
  sx40hs (1.00d, 1.00g & 1.00i)
  g1x (1.00e, 1.00f & 1.00g)

 

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