Thanks, and G9 motion detection with flash

mgxxx

14

Re: Thanks, and G9 motion detection with flash

« Reply #10 on: 31 / January / 2009, 07:42:18 »

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Hi David,

I will have to play with this. I think what is possibly happening is that the flash fires at the very end of the period the shutter is opened ( although it seems longer that that). So on longer exposures eg 1/60th second my pseudo bat flying past the camera has gone by th e time the flash fires. I will check p151 though.

I will try and sort this out by trying to establish the time the object is in front of the lens, and use a range of exposure times.

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Microfunguy

4037

Re: Thanks, and G9 motion detection with flash

« Reply #11 on: 31 / January / 2009, 08:00:22 »

Quote from: mgxxx on 31 / January / 2009, 07:42:18

I will have to play with this.

The more I think about it, I would use a PIR detector rather than the MD script.

If you set SDM focus mode (in Bracketing/Overrides) to 'Manual', at the top of the screen 'Direct' will change to 'Fast'.
In that mode, the photo is taken as soon as the USB voltage is detected, it does not wait for shutter release (required for synching two cameras for stereo).
No script needed.
Set your flash to first curtain.

David

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mgxxx

14

Re: Thanks, and G9 motion detection with flash

« Reply #12 on: 31 / January / 2009, 08:32:38 »

The penny has dropped....of course , the curtain setting is what I described.

I haven't tried PIRs to detect small bats - I thought MD seemed like a very nifty solution.

Thanks as always for your advice, David.
Terry

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mgxxx

14

Re: Thanks, and G9 motion detection with flash

« Reply #13 on: 31 / January / 2009, 08:51:07 »

Success!!!!

Had to recharge my battery but just tested it on first curtain. Works a treat. In fact on 1/500th second. And fungey if you are there - the system now seems to work well - just took several pics and the camera didn't crash even on faster shutter speed.
These are all pretty quick experiments ( have some nice kitchen bits and pieces in flight)

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fudgey

1705
a570is

Re: Thanks, and G9 motion detection with flash

« Reply #14 on: 31 / January / 2009, 10:41:58 »

Quote from: mgxxx on 31 / January / 2009, 06:36:35

But if I use a FASTER shutter speed then the script gives an error message and it all crashes."

The script gives an error message?

If my memory serves me right, the script should never give error messages. Any error message you get would be from ubasic, and that especially should never happen unless you have a corrupt copy of the script (which can happen for instance if you cut&paste things instead of just copying the file properly) or an obsolete version of CHDK (I know SDM has some differences in ubasic compared to trunk CHDK, I hope it includes the get_shooting, get_flash_mode, get_mode, get_video_button commands used by current MDFB versions?).

Note: current script version is MDFB-080914, and current CHDK is whatever is available in autobuilds (unless your camera is only being ported, in which case anything can be expected to be wrong). But if it now works for you with current SDM, no need to fix what isn't broken I suppose.

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