Canon PowerShot A1200

theused69

2

Re: Canon PowerShot A1200

« Reply #100 on: 28 / October / 2012, 11:46:44 »

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I've been trying to use CHDK to remove the 10 minute limit on my A1200 1.00A, but it's not working.

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waterwingz

12140

Re: Canon PowerShot A1200

« Reply #101 on: 28 / October / 2012, 11:52:50 »

Quote from: theused69 on 28 / October / 2012, 11:46:44

I've been trying to use CHDK to remove the 10 minute limit on my A1200 1.00A, but it's not working.

That would be because its not implemented in the A1200 .. or most CHDK cameras for that matter.

Its on my "to do" list to look into it - as for a change I actually have the camera to test with.

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Ported : A1200 SD940 G10 Powershot N G16

waterwingz

12140

Re: Canon PowerShot A1200

« Reply #102 on: 29 / October / 2012, 20:07:12 »

I've successfully extended the video time limits for the A1200 to four hours in 240 & 480 resolution modes and 2 hours in HD 1280 mode. Those new limits are somewhat arbitrary. I suspect that the limit for video length on this camera is now determined mostly by the 4G file size limit.

link > A1200 f/w 1.00A & 1.00B
link > A1200 f/w 1.00C

I've tested the 1.00c version myself but would like feedback from someone else. During testing, sensor temperature rose from 27 deg C to 46 deg C in the first five minutes and then leveled out and stayed at 47 deg C after about 10 minutes.

The 1.00a & 1.00b need testing before I submit them to the autobuild. Your feedback would be appreciated.

« Last Edit: 29 / October / 2012, 20:10:59 by waterwingz »

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Ported : A1200 SD940 G10 Powershot N G16

theused69

2

Re: Canon PowerShot A1200

« Reply #103 on: 30 / October / 2012, 10:13:51 »

I was totally not expecting a reply, even moreso a complete update of the firmware. I feel like a happy camper now

Anyway, I was able to record 25 minutes thanks to the latest 1.00A firmware, but stopped after the sensor went to 54 deg C. I wanted to test what would happen if all the 4GB space would get used up, but that would have to wait for another day.

Will appreciate it if you will provide a PS.FI2 file, so I can test it with my other 32GB SD card.

I'm also willing to test other features of CHDK on my 1.00A A1200, but I'm not that skilled with photography to begin with.

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waterwingz

12140

Re: Canon PowerShot A1200

« Reply #104 on: 30 / October / 2012, 10:56:50 »

Quote from: theused69 on 30 / October / 2012, 10:13:51

Anyway, I was able to record 25 minutes thanks to the latest 1.00A firmware, but stopped after the sensor went to 54 deg C.

I've been doing a little research into sensor temperature. What I've found is mostly about what happens to the signal-to-noise ratio as the temperature goes up (i.e. it gets worse). If someone has a source of a spec sheet for a typical camera sensor (CCD or CMOS) I would be very interested to see what the maximum listed ambient temperature is. And even that probably just tells us the max temp that the sensor will perform to spec - not the temperature at which sensor failure might occur.

Also, do we know where the sensor temperature comes from ? If its build-in to the sensor then it will read much higher than ambient.

Just for fun, I ran a one hour video at low resolution and found that the temperature rise of the sensor (as reported by CHDK) was the same as it is for HD video. So it seems Canon was not concerned about temperature exclusively when they set the 10 minute limit. Especially as they could easily monitor sensor temperature and shut down when it gets too high. In fact, they may very well already do just that.

However, a "hot" sensor might be just fine for the sensor but dangerous to components around it. P&S camera manufacturers pack a lot of stuff in a very small space for an amazingly low price. Its not hard to see things shifting a bit at temperature extremes. I actually found a Canon service notice that suggested this was happening with some older cameras : http://canoncanada.custhelp.com/app/answers/detail/a_id/4304/~/service-notice%3A-ccd-image-sensor-advisory
http://www.imaging-resource.com/badccds.html#cause
- read the detailed description of the malfunction.

Quote

Will appreciate it if you will provide a PS.FI2 file, so I can test it with my other 32GB SD card.

A ps.fi2 file will get released when this update goes into the autobuild. However, you don't need it as you can format your 32G card with a single FAT32 partition for autobooting. Just follow the instructions given here : http://chdk.wikia.com/wiki/Prepare_your_SD_card#For_Cameras_Released_After_2010_:

« Last Edit: 30 / October / 2012, 11:06:50 by waterwingz »

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Ported : A1200 SD940 G10 Powershot N G16

waterwingz

12140

Re: Canon PowerShot A1200

« Reply #105 on: 30 / October / 2012, 14:15:26 »

Update on HD Movie Limitations

I formatted an 16G SD card as exFAT in my Win7PC, copied over my latest A1200 version of CHDK with the time limits removed and created a new video. I was a little worried whether the A1200 (an early 2011 camera) would use the exFAT partition but it seemed quite happy with it.

Despite being formatted exFAT, the video recording ended after 26 minutes when the MOV file size hit 4,193,150 KB. The resulting video plays perfectly on my Win7 machine (my linux box won't read exFAT it seems).

So the 4G limit is something the camera enforces despite the card being formatted exFAT. Not sure if that's true for 2012 cameras but there you are. Any further removal of limits will require more code spelunking I'm afraid.

(fyi .. maximum sensor temperature hit 50 deg after about 15 minute and then went no higher)

« Last Edit: 30 / October / 2012, 14:17:55 by waterwingz »

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Ported : A1200 SD940 G10 Powershot N G16

kakkernak

8

Re: Canon PowerShot A1200

« Reply #106 on: 01 / November / 2012, 10:14:02 »

I tried the latest build on my 1.00A but couldn't get past the 10 minute movie limitation (1280 resolution).
At 9:49 the timer turned yellow/orange but at 9:59 the recording stopped.
Recording at smaller resolution seem to work, but haven't tried longer than a few seconds.

On another A1200 1.00A which I have hacked the hard-way (added a micro controller connected to RC gear to remotely switch camera on/off and trigger shutter button + removed the flash-light and capacitor) I cannot get the CHDK to work.
The lamp (between viewfinder and flash) lights up and stays that way. I have probably altered too much by removing the flash and capacitor for CHDK to boot up correctly?

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waterwingz

12140

Re: Canon PowerShot A1200

« Reply #107 on: 01 / November / 2012, 11:22:17 »

Quote from: kakkernak on 01 / November / 2012, 10:14:02

I tried the latest build on my 1.00A but couldn't get past the 10 minute movie limitation (1280 resolution).
At 9:49 the timer turned yellow/orange but at 9:59 the recording stopped.
Recording at smaller resolution seem to work, but haven't tried longer than a few seconds.

What version ? ( i.e. the full filename of the CHDK zip file you used).

Did you go into the video menu and enable "Video without time limit" ? Did you see a warning message about sensor may overheat at the bottom of the LCD display ?

Quote

On another A1200 1.00A which I have hacked the hard-way (added a micro controller connected to RC gear to remotely switch camera on/off and trigger shutter button + removed the flash-light and capacitor) I cannot get the CHDK to work. The lamp (between viewfinder and flash) lights up and stays that way. I have probably altered too much by removing the flash and capacitor for CHDK to boot up correctly?

I wouldn't think so. What you are seeing is typically what happens when you have the wrong firmware version loaded.

« Last Edit: 01 / November / 2012, 11:42:10 by waterwingz »

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Ported : A1200 SD940 G10 Powershot N G16

Microfunguy

4037

Re: Canon PowerShot A1200

« Reply #108 on: 01 / November / 2012, 11:28:21 »

Quote from: kakkernak on 01 / November / 2012, 10:14:02

I have probably altered too much by removing the flash and capacitor for CHDK to boot up correctly?

Try installing a 1 uF 400V capacitor instead.

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kakkernak

8

Re: Canon PowerShot A1200

« Reply #109 on: 01 / November / 2012, 15:59:53 »

Well ... what should I say. Feeling a little stupid actually.
First time using CHDK, and apparently I have a lot to learn.

1. I guessed the video limit fix was on by default when running CHDK, so of course I didn't check for any setting. Found the "video without time limit" and now I do get the "sensor may overheat..." message at the bottom of the screen.
I can now confirm that I was able to record 12 minutes with CHDK a1200-100b-1.1.0-full

2. Silly me, I thought I had two 1.00A cameras. But apparently my unaltered one is the 1.00A and the one hacked for RC is a 1.00C ... so, indeed wrong CHDK version for that camera.

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