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KAP & UAV Exposure Control Intervalometer Script

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Re: KAP & UAV Exposure Control Intervalometer Script
« Reply #260 on: 24 / August / 2014, 07:16:47 »
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Decided to try another test.  The settings this time: ND Filter was in use, focus was set to AFL, images taken at a 3sec interval, and meter filter factor was set to low.  The time interval also doesn't seem consistent as can be seen with the speeding up or slowing down of action in the video.
I'm travelling this week but I finished the little script that converts the log files into something I can easily analyze in a spreadsheet.  I'll look at timing first.
Ported :   A1200    SD940   G10    Powershot N    G16

Re: KAP & UAV Exposure Control Intervalometer Script
« Reply #261 on: 24 / August / 2014, 13:13:48 »
Decided to try another test.  The settings this time: ND Filter was in use, focus was set to AFL, images taken at a 3sec interval, and meter filter factor was set to low.  The time interval also doesn't seem consistent as can be seen with the speeding up or slowing down of action in the video.
Had a quick look at this on the plane today and it's quite interesting.  Here's a couple of plots from your log files - the shot number is on the X axis and the number of seconds between shots is the Y axis (one was the 3 second per shot log,  the other the 5 second per shot log)





Notice that the time goes from the requested 3 (or 5) seconds gradually out to about 13 second and then resets ever 150 shots (approx.).    The shot rate does not affect this - its consistently slowing down over the course of 150-160 shots.  When the reset occurs,  the script runs at a 2 second shot rate until it catches up with the time it missed shooting slow.

I can't explain the slow down based on anything the script is doing.  In fact,  when the shots gets slow,  the rate at which the script can write subsequent lines to the log also slows down.

Which brings me to a theory that this is related to SD card writing.  The script just seems to get ahead of the camera's ability to write to the SD card.    It might be interesting to see what happens if you change the image size / compression to smaller, more compressed images.  Does that increase the number of shots until it slows down ?

Ported :   A1200    SD940   G10    Powershot N    G16

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Offline MarkB

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Re: KAP & UAV Exposure Control Intervalometer Script
« Reply #262 on: 30 / August / 2014, 12:37:04 »
This is interesting.  I have tried other intervalometer scripts and the fast I could get the camera to shoot at was 2 to 2 1/3 seconds between shots.  This was with drivelapse and I didn't get any noticeable shift in time interval but had some focusing issues with it.  With other scripts I probably had a smaller pixel dimensions and may or may not have had superfine in the CHDK menu turned on.

I am happy to try another test this weekend if there is a set of parameters you would like me to try outside of smaller file size and quality override turned off.  And I still don't find the images as sharp when running the script as I do do when just taking a shot with no script running.

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Offline MarkB

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Re: KAP & UAV Exposure Control Intervalometer Script
« Reply #263 on: 30 / August / 2014, 17:42:13 »
Decided to try another test this afternoon.  ND Filter was in use, focus was set to AFL, images taken at a 5sec interval, and meter filter factor was set to medium.    Interval seems to drift but not as much as the last test,  focus seems to hold, but lots of flicker with exposure, which is odd since the lighting conditions didn't change much. Had a major error and the sequence stopped early.  See error at the end of the log.  Though this might have to do that I was saving RAW files by accident and the 16g card ran out of memory,

http://youtu.be/DPW9MGtISCg




« Last Edit: 30 / August / 2014, 17:44:32 by MarkB »


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Re: KAP & UAV Exposure Control Intervalometer Script
« Reply #264 on: 31 / August / 2014, 12:53:15 »
Did another test befor and after sunset with filter factor set to medium.  Lots of flickering and the change in speed.

http://youtu.be/RH_8iu80SDw

One note, I set this for 3000 images and it stopped before that.  I wasn't home so don't know if there was an error message.  The camera was powered off and the lens was still extended.  Hit the power to turn it back on then off again to retract the lens.


Re: KAP & UAV Exposure Control Intervalometer Script
« Reply #265 on: 31 / August / 2014, 13:10:42 »
Are you recording RAW/DNG in any of these ?
Ported :   A1200    SD940   G10    Powershot N    G16

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Re: KAP & UAV Exposure Control Intervalometer Script
« Reply #266 on: 31 / August / 2014, 19:54:55 »
Only recorded RAW once by accident on Test 7. 

Re: KAP & UAV Exposure Control Intervalometer Script
« Reply #267 on: 01 / September / 2014, 10:57:45 »
Had a major error and the sequence stopped early.  See error at the end of the log.  Though this might have to do that I was saving RAW files by accident and the 16g card ran out of memory,
The error occurred because the camera stopped being ready to shoot within 2 seconds after a half-press.  Once it got into that mode, it appears to have become stuck in that mode.  I don't see anything in the log that might have caused that - the scene illumination had not shifted much.

However, the fact that you were saving RAW suggests a possible issue with processor / SD card write overloading.

Did another test befor and after sunset with filter factor set to medium.  Lots of flickering and the change in speed.

One note, I set this for 3000 images and it stopped before that.  I wasn't home so don't know if there was an error message.  The camera was powered off and the lens was still extended.  Hit the power to turn it back on then off again to retract the lens.
No lockup reported in the log like the one we saw in series 7.   The same time sequence thing is happening though :

The write speed to the SD card slows down after a while,  and then seems to release and the script run at a 2 second interval to catch up.

Focus still bounces around with this series,  and the ND filter goes in & out.    I'll look at the exposure variations next - I may want to see some of the original images if you still have them.

One thing we could also try is to  isolate the timing glitches is a simplified intervalometer script that just shoots every 4 seconds in AUTO mode and that also logs to the SD card.
Ported :   A1200    SD940   G10    Powershot N    G16


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Re: KAP & UAV Exposure Control Intervalometer Script
« Reply #268 on: 01 / September / 2014, 12:52:45 »
I didn't keep any of the RAW files but I do have the jpeg's from test 7, I also have the jpeg's from test 8.  I only had RAW files saved for the one test and none of the others.  Just lest me know which jpeg's you would like to see.

I would be happy to test a simplified intervalometer script that just shoots every 4 seconds in AUTO mode and that also logs to the SD card, is there one you suggest?  As a note I usually shoot in program mode, would that affect the results in any way?

For fun I did a test with the AUTOEXP3 script yesterday set at a shot every 3 seconds.  It seems to hold the 3 seconds.  Unfortunately it does not have a longing option.

http://youtu.be/4QjnLxLmG9E


Re: KAP & UAV Exposure Control Intervalometer Script
« Reply #269 on: 01 / September / 2014, 13:46:05 »
I didn't keep any of the RAW files but I do have the jpeg's from test 7, I also have the jpeg's from test 8.  I only had RAW files saved for the one test and none of the others.  Just lest me know which jpeg's you would like to see.
JPG will be all I need.  I'll let you know.

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I would be happy to test a simplified intervalometer script that just shoots every 4 seconds in AUTO mode and that also logs to the SD card, is there one you suggest?  As a note I usually shoot in program mode, would that affect the results in any way?
Program mode is fine.  Attached is a stripped down script that lets the camera control the focus and exposure and logs every shot. Let's see if it slows down every 300 pictures or so as well?  It's possible that opening and closing the log file for each log line is causing part of the problem.

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For fun I did a test with the AUTOEXP3 script yesterday set at a shot every 3 seconds.  It seems to hold the 3 seconds. 
Does the exposure not seem to flicker here too?  Looks a bit like that to me.
Ported :   A1200    SD940   G10    Powershot N    G16

 

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