shoot immediately on remote press

mellow-yellow

shoot immediately on remote press

« on: 01 / July / 2012, 18:50:50 »

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In the past, I have successfully triggered two SX200IS cameras immediately upon USB remote keypress using Stereo Data Maker (SDM) in S_Fast mode. Now that I've loaded CHDK onto two Powershot A2200's, I need to do the same -- that is, fire both cameras immediately *without focusing* first. How do I override focus to accomplish this? Or is that the right approach?

In my current CHDK setup, this doesn't happen, as explained by here (http://chdk.wikia.com/wiki/USB_Remote_Cable#Homemade_USB_remote_cable), because the camera simply does a "half press" first. I'm a scripting beginner with UBasic, but I have programming experience. How can I make both cameras shoot immediately upon receiving the USB remote signal? Thanks!

« Last Edit: 01 / July / 2012, 18:55:12 by mellow-yellow »

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waterwingz

12058

Re: shoot immediately on remote press

« Reply #1 on: 01 / July / 2012, 19:05:14 »

Quote from: mellow-yellow on 01 / July / 2012, 18:50:50

fire both cameras immediately *without focusing* first.

Not sure what you mean by "not focusing first". A simple script like this will focus and set exposure and then wait for the USB remote to trigger it.

Code: [Select]

@title Simple USB Sync
press "shoot_half"
do 
    sleep 50
until get_shooting = 1
do
      wait_click 1
until is_key "remote" 
click "shoot_full_only" 
sleep(1000)
release "shoot_half"
end

Is that what you are looking for ?

A better way to do this more precisely is to use CHDK's built-in "sync" capability. This is a lot easier to use in the new dev trunk but in both cases, you activate the USB remote ( 5V on) and then release it ( 5V off) when you want to trigger both cameras. The timing that way is about as precise as you are going to achieve.

« Last Edit: 01 / July / 2012, 19:07:16 by waterwingz »

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Ported : A1200 SD940 G10 Powershot N G16

mellow-yellow

Re: shoot immediately on remote press

« Reply #2 on: 01 / July / 2012, 19:38:39 »

Thank you Waterwingz. I modified the "Remote button" script (similar to http://chdk.setepontos.com/index.php?topic=8039.0), which works almost (see below) perfectly, since I don't need sync'ing on release, but rather shooting on button press. I load the script below (saved to CHDK/Scripts/remote.bas), then press <ALT>, then the trigger and voilà!

Code: [Select]

@title Remote button
while 1
  wait_click 1
  if is_key "remote" then click "shoot_full"
wend

end

However, I also need to adjust the following settings (which won't change throughout the photo session)
1. "macro" distance (manual focus?)
2. brightness (ISO and f-stop?)

Do I set Disable Overrides to "Disabled" and make the settings there, here in the code, or elsewhere?

« Last Edit: 01 / July / 2012, 19:44:02 by mellow-yellow »

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waterwingz

12058

Re: shoot immediately on remote press

« Reply #3 on: 01 / July / 2012, 19:50:00 »

Quote from: mellow-yellow on 01 / July / 2012, 19:38:39

However, I also need to adjust the following settings (which won't change throughout the photo session)
1. "macro" distance (manual focus?)
2. brightness (ISO and f-stop?)
Do I set Disable Overrides to "Disabled" and make the settings there, here in the code, or elsewhere?

You can try both with script settings. Easier than setting manual overrides every time you fire up the cameras.

However, on many cameras, the manual focus stuff is reported to be problematic. I don't know if the A2200 has that issue or not.

As far as brightness goes, setting ISO, aperture (does the A2200 actually have an adjustable one ?), ND filter and more important, shutter speed is easily done with a script. You can even have it measure the correct exposure at the start of the script and lock the value in for the duration.

« Last Edit: 01 / July / 2012, 20:09:16 by waterwingz »

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Ported : A1200 SD940 G10 Powershot N G16