Camera Trigger Too Slow?

ThatGuyOverThere

4

« on: 22 / July / 2015, 18:12:57 »

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Hello,

I have been using a PixHawk to trigger my Canon PowerShot SX260 (equipped with CHDK) in a UAV and it seems to be sending voltage pulses too quickly. The camera will take pictures while running the predetermined flight path, then continue to take pictures even when it was put into manual mode (pictures should stop) and we will have images all the way up to when it lands and sometimes it will even continue to take pictures of the ground while it's just sitting there.

My initial theory is due to a "build-up" of these pulses since the camera can't register them fast enough, but I'm not sure if that's possible. I consistently notice the camera won't take nearly as many pictures as it was supposed to, as well. Is there an ideal speed to send these voltages? I seem to produce relatively good results when the camera takes a picture every 2.7s, but I have only been able to get it to do that once and am still having some issues.

That being said, is there any way to reduce the amount of time it takes the camera to take a picture utilizing CHDK? So I wouldn't have to slow the voltage pulses and can just increase the picture speed of the camera?

Any insight/comments are welcome!

Thanks

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waterwingz

12138

Re: Camera Trigger Too Slow?

« Reply #1 on: 22 / July / 2015, 18:29:33 »

Quote from: ThatGuyOverThere on 22 / July / 2015, 18:12:57

I have been using a PixHawk to trigger my Canon PowerShot SX260 (equipped with CHDK) in a UAV and it seems to be sending voltage pulses too quickly. The camera will take pictures while running the predetermined flight path, then continue to take pictures even when it was put into manual mode (pictures should stop) and we will have images all the way up to when it lands and sometimes it will even continue to take pictures of the ground while it's just sitting there.

Are you using a script with CHDK or just triggering via the built-in CHDK USB remote functionality? If you are using a script then which one?

Quote

My initial theory is due to a "build-up" of these pulses since the camera can't register them fast enough, but I'm not sure if that's possible.

Depending on how you are using the CHDK functionality there is one way to use a small internal buffer that will hold the last 8 "commands". But for most of the USB remote modes, there is no buffer.

Quote

I consistently notice the camera won't take nearly as many pictures as it was supposed to, as well. Is there an ideal speed to send these voltages? I seem to produce relatively good results when the camera takes a picture every 2.7s, but I have only been able to get it to do that once and am still having some issues.

That's pretty much normal for most Canon P&S cameras when they have to focus & set exposure before each shot.

Quote

That being said, is there any way to reduce the amount of time it takes the camera to take a picture utilizing CHDK? So I wouldn't have to slow the voltage pulses and can just increase the picture speed of the camera?

To go much faster you have to run the camera in continuous mode with the focus and exposure locked. There is a long discussion currently being held about this starting here : http://chdk.setepontos.com/index.php?topic=10822.msg123007#msg123007 . We now have that script taking photos at rates faster than one shot per second, syncronized distance over the ground by the pixhawk.

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Ported : A1200 SD940 G10 Powershot N G16

ThatGuyOverThere

4

Re: Camera Trigger Too Slow?

« Reply #2 on: 23 / July / 2015, 18:52:46 »

"To go much faster you have to run the camera in continuous mode with the focus and exposure locked. There is a long discussion currently being held about this starting here : http://chdk.setepontos.com/index.php?topic=10822.msg123007#msg123007 . We now have that script taking photos at rates faster than one shot per second, syncronized distance over the ground by the pixhawk."

Is there a way to put parts of this Intervalometer script into a USB-triggered script? Unfortunately, the way I am using my camera in the UAV requires the USB input. Or can this be done simply by using the camera in continuous mode and running the regular script we already have?

I know it's possible to just use the Intervalometer script, but then I assume once the script is ran, the camera will start rapidly taking pictures and won't be connected to the pixhawk, but unfortunately, for my purposes this isn't ideal.

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waterwingz

12138

Re: Camera Trigger Too Slow?

« Reply #3 on: 23 / July / 2015, 19:03:37 »

Quote from: ThatGuyOverThere on 23 / July / 2015, 18:52:46

Is there a way to put parts of this Intervalometer script into a USB-triggered script? Unfortunately, the way I am using my camera in the UAV requires the USB input. Or can this be done simply by using the camera in continuous mode and running the regular script we already have?

I know it's possible to just use the Intervalometer script, but then I assume once the script is ran, the camera will start rapidly taking pictures and won't be connected to the pixhawk, but unfortunately, for my purposes this isn't ideal.

If you had a chance to read through the thread I linked, you would probably have noticed that everything after the post I linked was about triggering the script via the camera's USB port connected to one of the pixhawk's servo outputs.

What do you mean when you say "the way I am using my camera in the UAV requires the USB input"? I'll need to know a lot more about how you have your system configured before I can comment further.

Logged

Ported : A1200 SD940 G10 Powershot N G16