Canon Powershot S70 & power-on defaults

cgaertner

2

« on: 16 / September / 2010, 17:18:10 »

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Hi!

I hope this is the correct forum for my post - otherwise please apologize and point me to the right one!

I use a Canon Powershot S70 for time lapse photography. The camera is directly connected to a power supply and has to be set to manual focus (distance infinite) and infrared mode. I use an external device (pclix) to generate an infrared signal e.g. every minute that makes the camera take a photo.

This works fine for days and even weeks while the power is never interrupted. But if this happens (even only for a few seconds), the power-on default values of the camera are (1) autofocus instead of manual focus and (2) infrared mode deactivated, which causes the camera not to respond to the infrared signal and for this reason no more photos are taken.

From this site, I have learned, that it is possible to replace the camera's "operating system" with one that resides on the cf-card, which is completely new for me. I have also read, that CHDK will never be available for the Canon Powershot S70 due to an incompatible image sensor (I hope, I got this right).

For this reason, I have two questions:

- Is it possible to change the firmware of the camera in a way that the power-on defaults are manual focus (distance infinite) and infrared enabled? The creators of CHDK must have a deep knowledge of the camera's internals so if someone is capable of this, it would be them!

- Is it possible to have a script on the cf-card, which does not replace the camera's operating system (because that would not work, see FAQ) but is executed during power-on and just changes these two settings. These settings could be changed by a few keystrokes which I can provide if needed.

I hope it is clear what I mean, if not, please don't hesitate and ask me.

Thanks for your attention and I hope there is a solution for my needs.

Greetings, Chris

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reyalp

14080

Re: Canon Powershot S70 & power-on defaults

« Reply #1 on: 16 / September / 2010, 18:00:31 »

Quote from: cgaertner on 16 / September / 2010, 17:18:10

From this site, I have learned, that it is possible to replace the camera's "operating system" with one that resides on the cf-card, which is completely new for me.

Can you link the source where you found this information ? Note that the fact this is possible on some cameras does not mean it is possible on all.

Quote

I have also read, that CHDK will never be available for the Canon Powershot S70 due to an incompatible image sensor (I hope, I got this right).

Not the image sensor, but the fact that the CPU and operating system are completely different. Digic I use X86 and DOS, while Digic II and later use ARM and vxworks or dryos. So it doesn't make any sense to talk about CHDK on Digic I: not because Digic I cannot be hacked, but this hack would have to be completely from scratch, and the knowledge that CHDK is based on (which is the result of many thousands of hours of work by many people) would be almost completely useless.

This site: http://rayer.ic.cz/hardware/a70.htm has good information about hacking Digic I cameras. Use google translate if you don't speak Czech. Given the age of these cameras, I doubt you will find anyone actively working on them, or interested in doing so.

Quote

- Is it possible to change the firmware of the camera in a way that the power-on defaults are manual focus (distance infinite) and infrared enabled? The creators of CHDK must have a deep knowledge of the camera's internals so if someone is capable of this, it would be them!

As I described above, what we know from CHDK doesn't tell us anything about your camera. From the site I linked above, it looks like this should be possible in theory. In practice, unless someone has already figured out how to do it for this specific camera, the effort required to accomplish it is likely to be very significant. Unless you have good reverse engineering skills, it's unlikely to happen. Even if you do, the value of the time required to accomplish it would vastly outweigh the cost of buying a CHDK supported camera instead. Or investing in a good UPS

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Don't forget what the H stands for.

cgaertner

2

Re: Canon Powershot S70 & power-on defaults

« Reply #2 on: 17 / September / 2010, 10:03:35 »

Thanks reyalp for your answers!

Quote from: reyalp on 16 / September / 2010, 18:00:31

Can you link the source where you found this information ? Note that the fact this is possible on some cameras does not mean it is possible on all.

Yes, of course, I know that this technique is available only on *certain* cameras. Sorry I did not point out clearly. I was just fascinated by the fact that it *is* possible to replace some Canon camera's OS. I have never thought about this.

Quote from: reyalp on 16 / September / 2010, 18:00:31

Not the image sensor, but the fact that the CPU and operating system are completely different. Digic I use X86 and DOS, while Digic II and later use ARM and vxworks or dryos. So it doesn't make any sense to talk about CHDK on Digic I: not because Digic I cannot be hacked, but this hack would have to be completely from scratch, and the knowledge that CHDK is based on (which is the result of many thousands of hours of work by many people) would be almost completely useless.

Thanks for the details.

Quote from: reyalp on 16 / September / 2010, 18:00:31

As I described above, what we know from CHDK doesn't tell us anything about your camera. From the site I linked above, it looks like this should be possible in theory. In practice, unless someone has already figured out how to do it for this specific camera, the effort required to accomplish it is likely to be very significant. Unless you have good reverse engineering skills, it's unlikely to happen. Even if you do, the value of the time required to accomplish it would vastly outweigh the cost of buying a CHDK supported camera instead. Or investing in a good UPS

Again thanks, I am aware of the fact that the Powershot S70 is a rather old model. But it turned out that it is hard to find a camera that has an infrared sensor that is compatible to the pclix device that I use for time lapse photography. The built-in time lapse features of many cameras have too much limitations (e.g. only a maximum of 99 or 999 pictures can be taken or the interval cannot be set to my needs). For this reason I am happy with the pclix device, with the downside of the power-issue.

And I need a camera which can be connected to a power supply instead of using a battery.

As I have learned, there would be no need for the external pclix device because time lapse photography could easily be done with a CHDK compatible camera, CHDK and a script.

I already thought buying some small UPS but this makes the whole equipment more heavy and less easy to be taken to holidays etc. Maybe I do not need a fully featured UPS but some small battery pack to fill the time during the main power is not available.

Thanks, Chris

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