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Long exposures in radioactive environment

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Long exposures in radioactive environment
« on: 09 / July / 2014, 08:10:25 »
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Hi guys,

I've been using CHDK for almost as long as I've been doing photography (discovering it allowed me to escape the limitations of the semi-auto just as I began to understand them), so I am quite familiar with it but now I want to step up and contribute. I am a software developer myself (although my C is a bit rusty, you never forget C:), although I don't have much experience with this kind of reverse-engineering. But between cheap and cheerful Powershots and Magic Lantern on my 500D, it's really ought to happen sooner or later, I've already been wanting to write some custom features for my camera for some time.


The reasons for posting this here are two-fold:
1. I am thinking about buying a used A2500 within the next 1 or 2 days to take on a trip to the Chernobyl Zone of Alienation in 2 weeks.

My plan is to take long-duration timelapses and of course this becomes feasible only thanks to CHDK. However, I only have enough time to buy 1 camera, the other one I found is an older A800 which might not be adequate for extremely low light (I plan on taking 1-min exposures all night, or even longer if the 64sec barrier has been cracked since I last checked), but has a port marked stable.
Remember there isn't even any light pollution anywhere within 30km, so the best I can expect to work with is a little bit of moonlight and ionizing radiation :)


TL;DR:
What I would like to ask you guys before I pick a camera is:
Are there any known bugs in the present alpha build for the A2500 that could hamper a simple intervalometer script, or running for extended periods doing long exposures?

I've read through the A2500 porting thread, but I'm still not sure and I can't test before I commit myself.


This brings me to
2. Being fully aware that all of you are doing this for the sake of the challenge and intellectual curiosity, I'm not expecting you guys to help if you don't want to, but I can offer at least something in exchange.
After returning from Chernobyl, I will devote the camera (whichever one, I'm eyeing A800/A1400/A2500 atm but anything that's good at low-light and being-cheap will do :) ) entirely to CHDK testing purposes.
I will post firmware dumps, test results, continually download and run code you guys are developing for it and document what happens, in addition to general-usage testing of CHDK. Once (or if) I get familiar enough with the code, I'll try to actually help myself, although I'll probably start by writing something for my PC to mess with the camera via PTP.


My budget and time are both limited but I'll be damned if I don't try to get the most out of a trip to the Zone. I would really appreciate any insight from you guys.

Besides, who wouldn't want to see how a Powershot and its sensor deals with radiation? :)


PS.

I also have an A460, A530, A560 and A2000 in various states of hard-brick that I definitely want to bring back to life (they're all damaged, but the mainboard, CPU, card slot & image sensor work in all of them). These have the advantage of being ripe for hardware experimentation since they are already inoperable as they are. One of the things I want to try is remove the original lens assembly (+ bypass hardware checks) and try to fit a custom lens to the A2000 for use as a microscope.


Re: Long exposures in radioactive environment
« Reply #1 on: 09 / July / 2014, 09:05:39 »
As  you seem to know,  the whole "Alpha" "Beta" status thing with CHDK is perfectly arbitrary.   Reading the porting thread (as you did) is about as good as it gets.

I don't have an A2500 but I do have a few other Powershot models.  FWIW, if all you want is an intervalometer then almost any port of CHDK that will load and run can do that.

For your application,  you might want to look at this :  Meteor Intervalometer with Dark Frame Management   It will deal with longer exposures than 60 seconds (which should work for any CHDK camera now) and more important, let you manage "dark frames" in your shooting process.
« Last Edit: 09 / July / 2014, 09:23:17 by waterwingz »
Ported :   A1200    SD940   G10    Powershot N    G16

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Offline blackhole

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Re: Long exposures in radioactive environment
« Reply #2 on: 09 / July / 2014, 09:46:43 »
I do not know how familiar you are with CHDK, but you might want to first see what they look like images, made with an exposure of 64 seconds, the result might have been disappointing. Do not forget that this is a very small sensor.
If you go into the Zone as a tourist, you probably will not be into area with high radiation,sensor may not be able to record that level of radiation.
It will certainly be an unforgettable experience.
It would be nice to see the photos made there.
Good Luck!

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Offline reyalp

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Re: Long exposures in radioactive environment
« Reply #3 on: 09 / July / 2014, 21:27:20 »
For your application,  you might want to look at this :  Meteor Intervalometer with Dark Frame Management   It will deal with longer exposures than 60 seconds (which should work for any CHDK camera now) and more important, let you manage "dark frames" in your shooting process.
The method used used to take dark frames might also be the best chance of detecting radiation effects too. Comparing dark frames taken before entering the zone should at least tell you if there is a noticeable effect.

The a2500 port should support exposure longer than 64 sec. On my elph130, I've used exposures up to 4 minutes and have found the results aren't too bad if you use a dark frame.
Don't forget what the H stands for.


 

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