Manual focus for video recording

Solone

1

« on: 20 / October / 2012, 17:49:45 »

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Hi everybody,
I'm not sure if this currently exists, but it seems you cannot specify a manual focus distance when recording a video clip? I have a powershot A480 which I would love to make super macro video clips with as well as a powershot A1200 that i wih i could specify a focal distance for when making HD (1280 x 720p) clips. I have CHDK on both cameras. How much effort is involved in making the existing focus function affect video clips?
thanks in advance for great work so far.
Solone

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Razor512

94

Re: Manual focus for video recording

« Reply #1 on: 31 / March / 2013, 17:26:05 »

Would also like to see this, manual focus in video is one of the main features I missed in moving from my powershot a560 (1 button press would cause it to refocus)

Now with my sx230HS, the video seems to be in auto focus all the time with no way to get it into manual focus, or at least lock the focus and have a single button push to cause it to refocus like with the a560 running chdk allowed.

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srsa_4c

4451

Re: Manual focus for video recording

« Reply #2 on: 31 / March / 2013, 19:46:00 »

Quote from: Razor512 on 31 / March / 2013, 17:26:05

Now with my sx230HS, the video seems to be in auto focus all the time with no way to get it into manual focus, or at least lock the focus and have a single button push to cause it to refocus like with the a560 running chdk allowed.

Try the following Lua script. You need to be in movie mode. Unfortunately, this will likely crash the camera as would any other script during recording. Try it in a low res video mode, maybe that will help.
When the script is running and you're in ALT mode, the "UP" key will lock the focus, "DOWN" will unlock it. At least that is what's supposed to happen. You can press "MENU" in ALT mode to exit, or you can interrupt it the usual way.

Code: [Select]

--[[
@title AF lock test
--]]
-- don't run in play mode
rec,vid,mode=get_mode()
if rec~=true then
    error("ERR: not in rec mode!")
end

if (type(call_event_proc) ~= "function" ) then
    error("ERR: native calls are disabled!")
end

if (call_event_proc("SS.Create") == -1) then
    error("ERR: SS.Create failed")
end

while true do
    wait_click(5000)
    if is_pressed("down") then
       call_event_proc("PT_UnlockAF")
    elseif is_pressed("up") then
       call_event_proc("PT_DoAFLock")
    elseif is_pressed("menu") then
        break
    end
end

The DoAFLock method is from the SX220 porting thread. It's not enabled as "AF scan in video" replacement, because it crashes the camera when subject distance override (?) is active.

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Skybuck

5

Re: Manual focus for video recording

« Reply #3 on: 29 / September / 2014, 02:26:40 »

This is indeed one of the most annoying problems with Canon Powershot SX50 HS.

If it's auto focus fails, the user of the video mode is pretty much f*cked.

Zooming in and out may help the auto-focus to get the focus better, but when trying to zoom back in it might still f*ck up.

Really annoying, and really bad about this camera. I guess older cameras has a cicular control/numb to change focus but with this camera it's gone... pretty shitty.

Anyway, the dial could be used to change focus... I think that could be a nice option or the buttons as long as it doesn't suddenly "over-focus"... it has to do it gradually and such oh well... or maybe exponential... hmm...
centimeters, meters, etc... hmmm... or maybe just multiple buttons that's probably easiest/best:
centimeter adjustment button, meter adjustment button. so user can adjust focus quickly/largely or slowly/finely.

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Skybuck2002

2

Re: Manual focus for video recording

« Reply #4 on: 30 / September / 2014, 21:23:15 »

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