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is 1 frame / sec timelapse possible ?

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Offline tavis

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is 1 frame / sec timelapse possible ?
« on: 30 / December / 2012, 00:21:20 »
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I have an SX260 HS.  With the standard intervalometer script the fastest I can shoot is about 1 frame every 4 seconds. I want to get 1 frame / sec or faster.  Has anyone been able to shoot frames faster than 4 fps ?

I normally achieve this by just shooting video and trimming out frames but I'd rather do it with an external trigger and stills.

thanks

-tavis

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Offline reyalp

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Re: is 1 frame / sec timelapse possible ?
« Reply #1 on: 30 / December / 2012, 01:18:11 »
CHDK will definitely not let you shoot faster than the the built in continuous rate, and will be substantially slower using the simple intervalometer included with chdk. http://www.usa.canon.com/cusa/consumer/products/cameras/digital_cameras/powershot_sx260_hs#Specifications is a bit confusing, but it looks like your camera can do between 2.4 and 0.8 FPS in continuous mode depending on settings.

If you don't need a steady frame rate, you could just use continuous mode, using press() to hold the shutter down for the desired time or number of shots.

The standard intervalometer will try to do a full preshoot (auto focus, auto exposure, etc) before each shot, so it will be substantially slower than continuous mode. Using the kind of script discussed in http://chdk.setepontos.com/index.php?topic=1444.15 (which holds down halfshoot and repeatedly clicks shoot) should be substantially faster. Of course, this will not adjust focus and exposure between shots.

On my d10, the first (full preshoot) method tops out at about 3.1 seconds/frame, while the second manages about 1.6.  I forced 1/256th exposure for this, if you are shooting in low light the actual exposure time can be significant. I also used MF, which reduces the time required for the first method.

On some cameras there is a low light mode which is 1/2 resolution but much faster than normal shooting. Using CHDK, you can force the ISO to a lower value which regains some quality. Using this method on my d10, the first case is reduced to 2 sec/frame.

Normal (non low light/iso3200 etc) reduced resolution modes do not seem to shoot faster than full resolution, and in some cases are slower. High ISO settings that aren't a special reduced res mode can be slower too.

SD card speed probably isn't very significant if unless you are using something really terrible, but having a fast one won't hurt. My test above were done using a very slow card.

Forum user lapser has been doing some interesting work on faster intervalometer capabilities, discussed in these threads
http://chdk.setepontos.com/index.php?topic=8997.0
http://chdk.setepontos.com/index.php?topic=9172.0
This is his own custom code which is not currently included in CHDK, but he might have build you can try.
Don't forget what the H stands for.

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Offline lapser

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Re: is 1 frame / sec timelapse possible ?
« Reply #2 on: 30 / December / 2012, 02:35:14 »
Nice explanation, reyalp.

Do you need to adjust the exposure between shots?  If not, the fastest shot rate on the SX260 is about 2 shots per second, just by holding the shutter down in continuous mode. There's also another continuous mode with autofocus that's a little slower.  You can hold the shutter down in CHDK with a 2 line Lua script:
Code: (lua) [Select]
press("shoot_full")
repeat sleep(1000)until false
My experimental chdk build adjusts exposure and allows you to set a precise shot rate in continuous mode. If you're interested in helping me test it, let me know your firmware version number and I can post something for you to try on your camera. At the moment, it can shoot at a about 1.5 shots per second (750 msec per shot).
EOS-M3_120f / SX50_100b / SX260_101a / G1X_100g / D20_100b
https://www.youtube.com/user/DrLapser/videos

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Offline tavis

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Re: is 1 frame / sec timelapse possible ?
« Reply #3 on: 30 / December / 2012, 22:07:13 »
I've tested my camera's rate by holding half press and full pressing in succession and the rate is well over 1 fps so once I get the the usb half/full trigger working I should be good to go.  Thanks everyone.

-tavis


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Offline lapser

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Re: is 1 frame / sec timelapse possible ?
« Reply #4 on: 30 / December / 2012, 23:57:48 »
I've tested my camera's rate by holding half press and full pressing in succession and the rate is well over 1 fps so once I get the the usb half/full trigger working I should be good to go.  Thanks everyone.
You've probably also noticed that if you press too fast, the camera doesn't shoot. To get the fastest rate with the shutter button half pressed, you have to wait until the camera is ready before pressing the shutter. The timing depends on the shutter speed.

But you should be able to trigger shots from usb at a constant rate with half_press held. However, you can get an even faster rate with full press held in continuous mode. One advantage of continuous mode is that it displays the pictures on the screen as you shoot. There's also a continuous mode with autofocus that goes about 1 shot per second.

It sounds like you're having fun experimenting. I hope you'll post your progress, and some pictures when you have them. Good luck.
EOS-M3_120f / SX50_100b / SX260_101a / G1X_100g / D20_100b
https://www.youtube.com/user/DrLapser/videos

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Offline tavis

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Re: is 1 frame / sec timelapse possible ?
« Reply #5 on: 31 / December / 2012, 02:22:28 »
So I found the Ricoh pulses diagram for full and half press triggers via usb cable.  I can't seem to find any code on the web for arduino to produce these pulses.  I know I could write this myself but I'd rather just reuse code if its already out there.  Anybody have the code ? 

I wonder if the openmoco timelapse engine will do this for me but I haven't got that working yet so . . . anyway.   I'll see if I can program the pulses myself tomorrow.

And you won't be seeing images from me but timelapse movies (clouds are my favorite)

Lapser : I would like to test out your experimental build if you have it for my camera and firmware.  (SX260 HS with latest firmware)

Re: is 1 frame / sec timelapse possible ?
« Reply #6 on: 31 / December / 2012, 10:39:40 »
So I found the Ricoh pulses diagram for full and half press triggers via usb cable. 
http://chdk.wikia.com/wiki/USB_Remote#USB_Remote_Timing_Diagrams

Quote
I can't seem to find any code on the web for arduino to produce these pulses.  I know I could write this myself but I'd rather just reuse code if its already out there.  Anybody have the code ? 
I don't have the code (sorry) but if I was going to write it myself,  I'd probably implement the "two press" switch rather than the Ricoh CA-1.   Its a lot simpler and gives you pretty much all the same functionality.

Ported :   A1200    SD940   G10    Powershot N    G16

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Offline lapser

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Re: is 1 frame / sec timelapse possible ?
« Reply #7 on: 31 / December / 2012, 13:11:50 »
Lapser : I would like to test out your experimental build if you have it for my camera and firmware.  (SX260 HS with latest firmware)
Is that 101A firmware? It will take me a day or two to get something ready for you.
EOS-M3_120f / SX50_100b / SX260_101a / G1X_100g / D20_100b
https://www.youtube.com/user/DrLapser/videos


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Offline tavis

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Re: is 1 frame / sec timelapse possible ?
« Reply #8 on: 31 / December / 2012, 15:17:30 »
Yes, its 101A

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Offline tavis

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Re: is 1 frame / sec timelapse possible ?
« Reply #9 on: 31 / December / 2012, 18:51:16 »
So I've got my Arduino sending out pulses with the correct timing for the CA-1. 

I can get the camera to go half-press, full-press, and un-press. The problem is that it won't stay in half-press after a full-press.  What I need it to do is stay in the half press mode while I send multiple full-press pulses.  That way I can get frames faster. 

Is CHDK not mean to work like this ?

Does full-press always reset the state back to unpressed ?

I'm thinking now that I might need to use this in conjunction with my own script to handle the pulses and shooting states properly. 

Any ideas ?

Here is the C code for arduino to make the CA-1 pulses :
Code: [Select]
void halfPress() {
  Serial.println("halfPress");
 // 30 ms on then off
   buttonState = 1;
   digitalWrite(shutterPin, HIGH);
   delay(20);
   digitalWrite(shutterPin, LOW);
   // wait for focus and exposure
   delay(1500);
}

void fullPress() {
  if (buttonState == 0) halfPress();
  // 150 ms on then off
   digitalWrite(shutterPin, HIGH);
   delay(150);
   digitalWrite(shutterPin, LOW);
}

void unPress() {
  Serial.println("unpress");
  buttonState = 0;
 // 2 pulses in 90 ms
   digitalWrite(shutterPin, HIGH);
   delay(30);
   digitalWrite(shutterPin, LOW);
   delay(10);
   digitalWrite(shutterPin, HIGH);
   delay(30);
   digitalWrite(shutterPin, LOW);
}

-tavis

 

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