prevent autofocus on IXUS 75

jt256

13

« on: 02 / June / 2009, 10:12:30 »

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I was hoping the following would allow the camera to first set focus, and then just take pics after that without refocusing.

Code: [Select]

@title Lock Focus

press "shoot_half"

sleep 2000

for q=1 to 50
  click "shoot_full"
  sleep 1000
next q

end

But it forces a refocus everytime. I want to take sunset pics and sometimes the cam loses focus when it faces into the sun too much. So since my scene and tripod aren't moving I just want to focus once then lock it.

I saw a previous post with the lock focus command but that didn't work on my ixus 75. The script just hung.

Any tips for locking focus? I don't mind about exposure dynamically updating, I just want to keep focus the same.

Thanks a lot, John

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Microfunguy

4037

Re: prevent autofocus on IXUS 75

« Reply #1 on: 02 / June / 2009, 10:24:14 »

Quote from: jt256 on 02 / June / 2009, 10:12:30

I saw a previous post with the lock focus command but that didn't work on my ixus 75. The script just hung.

That script only works with SDM.

Temporarily rename your existing DISKBOOT.BIN and replace with ixus75 version from SDM website.

Before running script, fully-press shutter button to clear Synch mode.

Does the script work ?

David

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jt256

13

Re: prevent autofocus on IXUS 75

« Reply #2 on: 02 / June / 2009, 15:06:08 »

No, sorry this does not work.

Code: [Select]

@title aClick

rem init focus
  sleep_for 1000
  press "shoot_half"
  sleep_for 1000
  lock_autofocus
  sleep 1000
  "! locked"
  "! 'AFL' top left"
  release "shoot_half"
 
rem shoot without re-focusing
  while (1) 
    wait_for_switch_press
    click "shoot_full"
    "snap"
  wend
 end

I replaced the bin file with my ixus75 (1.02) version, and pushed the shutter button to take a pic in normal mode, then ran the script, but it just says "started" and then after 5 secs the screen goes black and I have to reboot the cam.

How about my initial code? Thanks for tips

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Microfunguy

4037

Re: prevent autofocus on IXUS 75

« Reply #3 on: 02 / June / 2009, 19:10:44 »

Quote from: jt256 on 02 / June / 2009, 15:06:08

No, sorry this does not work.

if you put 'rem' in front of 'lock_autofocus' , does the script still crash ?

How far does it get ?

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Microfunguy

4037

Re: prevent autofocus on IXUS 75

« Reply #4 on: 02 / June / 2009, 19:22:08 »

It is bedtime in the UK, so a final word ....

Using the CHDK build, you can add statement 'set_aflock(1)' after half-press to lock focus (after a suitable delay).

set_aflock(0) unlocks focus.

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jt256

13

Re: prevent autofocus on IXUS 75

« Reply #5 on: 02 / June / 2009, 21:21:08 »

Now we're talking! hooray, thanks,

Code: [Select]

set_aflock(1) is just the ticket!

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Microfunguy

4037

Re: prevent autofocus on IXUS 75

« Reply #6 on: 03 / June / 2009, 04:54:01 »

Quote from: Microfunguy on 02 / June / 2009, 19:22:08

set_aflock(1)' after half-press to lock focus

should be :-

set_aflock 1

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jt256

13

Re: prevent autofocus on IXUS 75

« Reply #7 on: 03 / June / 2009, 06:21:47 »

Interesting, this works just fine to me:

Code: [Select]

@title LockFocus
@param a Delay (secs)
@default a 5

sleep 500
press "shoot_half"
sleep 2000
set_aflock(1)
sleep 1000
set_backlight(0)

while (1)
  click "shoot_full"
  sleep(100)
  set_backlight(0)
  sleep a*1000
wend
 
end

What I can't understand is why the backlight will never go off? I don't understand why these commands are being ignored?

Thanks

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Microfunguy

4037

Re: prevent autofocus on IXUS 75

« Reply #8 on: 03 / June / 2009, 17:19:11 »

Quote from: jt256 on 03 / June / 2009, 06:21:47

What I can't understand is why the backlight will never go off?

That uBasic command is meant to work on all cameras.
It simply calls the corresponding Canon firmware function.

What happens if you try :-

@title test
sleep 1000
set_backlight 0
sleep 3000
set_backlight 1
end

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