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It seems that it is software possible, since there are strings in the FW.
It looks like guiUtil_sub_FF83B9DC() routine has many switch-cases and 3 of
them are responsible for limiting the camera to 1/4000s.
This means that it may be possible to unlock the 1/8000s though the limitation
is hardcoded, but I'm not sure it is physically possible for the camera.
This will have to wait for now, but thanks for the request.
Original comment by fired...@gmail.com
on 17 Aug 2012 at 11:15
Hmmm, you just made me more curious :) Would be very interesting to know
whether it is possible. It will be, IMHO, a major boost for this camera.
Thanks for the info!
Original comment by doffact...@gmail.com
on 17 Aug 2012 at 12:02
We know how to ask the camera to use a certain speed, the question is if the
camera will honor our request. From the info provided above, there seems to be
some hope that it will. On the other hand, we must remember that we are dealing
with hardware here, and we could break the shutter (if I recall correctly, this
is exactly what happened to the CHDK people).
Preparing a test is not complex at all, but I will not be the one who runs it...
Original comment by eduardo....@gmail.com
on 17 Aug 2012 at 12:15
Yes, I am 100% aware of the dangers. My interest is exactly in this, if this is
possible to make it in the firmware, how would react the shutter and its
hardware. Do you have it confirmed that the 400D on shorter speeds than 1/4000s
broke their shutters?
I do not have to explain you what would it mean to shoot for example at ISO100
@ 1/4000s and you have to use f/4 or f/3.6, instead of f/1.8 or lower ... which
you can achieve with 1/8000s ;)
Original comment by doffact...@gmail.com
on 17 Aug 2012 at 12:22
Here is a pseudo code from what I saw in the firmware:
IF (speed < 30s) {
do something
} ELSE IF (SPEED < 1s) {
do else
} ELSE IF (.....) {
....
} ELSE IF (speed < 1_4000) {
goto 1_4000;
} ELSE {
goto 1_4000;
}
so it is software blocked, it wont do 1/8000 unless we rewrite these routines
to unlock the shutter speed...
about the physical possibilities - I believe the camera will do 1/8000 and the
restriction is just like the others restrictions that should make you buy a
higher-end camera.
though, it would be great if we have a spare camera (even broken in some way)
just to test these dangerous scenarios...
in that matter of speaking:
http://www.magiclantern.fm/whats-new/78-news/133-defective-cameras
Original comment by fired...@gmail.com
on 17 Aug 2012 at 7:19
Ok, what you are talking about is exactly my suspicions, that the 400D is just
blocked with a software but maybe (?) it is possible to have the 1/8000s.
The question is then whether there is any camera available to try it out? Does
anybody have a spare 400D? :)
Original comment by doffact...@gmail.com
on 18 Aug 2012 at 10:54
I would be willing to test this on one of my cameras. I have 2 and one of them
is in pretty bad condition anyway. (lots of dead pixels, partly melted exposure
sensor)
Original comment by purest...@gmail.com
on 25 Aug 2012 at 5:50
Great! I'll prepare a test binary as soon as I return home.
Original comment by eduardo....@gmail.com
on 27 Aug 2012 at 10:21
cool - I'm ready to test as soon as I get the file...
Original comment by purest...@gmail.com
on 30 Aug 2012 at 9:43
Guys, this is great! I am looking forward for the test results. Fingers
crossed...
Original comment by doffact...@gmail.com
on 31 Aug 2012 at 6:07
Here it is!
Copy attached file to card, set camera to M mode, and launch the intervalometer
script. This will fire the test code; it will take 9 shots, starting with the
selected shutter speed, and increasing it (shorter exposure time) 1/8 EV each
time down to EV-1. It seems to work for "normal" exposure times; if camera is
set to 1/4000s, it should go down to 1/8000s (I did not try it myself).
On the other hand, this test closes issue 33: even if the script tries to use
all eight intermediate shutter speeds, the camera only uses a restricted set of
different exposure times.
Original comment by eduardo....@gmail.com
on 6 Sep 2012 at 1:10
Attachments:
hmmm, I tried launching the intervalometer script, it just takes a photo every
2 sec's all the same exposure. - maybe I'm missing something... I will try
again this afternoon when I have more time.
Original comment by purest...@gmail.com
on 8 Sep 2012 at 9:04
Sorry, my mistake: try the EAEB script, not the intervalometer.
Original comment by eduardo....@gmail.com
on 8 Sep 2012 at 9:07
ok, I ran the EAEB script,
with shutter setting at 1/4000. it took 9 photos, all with shutter time still
at 1/4000, and looking at the photos they all seem to be exposed equally.
Original comment by purest...@gmail.com
on 8 Sep 2012 at 12:52
That's bad news... This means we need to hack into the part of the code that
controls the shutter; and that is way out of what I can currently do.
Original comment by eduardo....@gmail.com
on 8 Sep 2012 at 1:10
Hi Eduardo (all). Why is it way out of what you can do? Is it impossible, or
just hard to achieve (so there is still some hope)? :P
Original comment by doffact...@gmail.com
on 8 Sep 2012 at 1:32
> Hi Eduardo (all). Why is it way out of what you can do? Is it impossible, or
just hard to achieve (so there is still some hope)? :P
Right now, most features implemented by 400plus rely on politely asking the
firmware to do nice things, and then the firmware talks to the hardware; this
is how we achieved spot metering, AF patterns, custom color temperature, ...
The file attached on comment 11 asks the firmware to use a shutter of 1/8000,
but it refused to acknowledge the request, and simply shot at 1/4000. So we
would need to dig deeper in the firmware, see how it takes a photograph, and
try to find a method to interfere in that process.
Being realistic, I think it is safe to assume that this feature is impossible
to achieve.
Original comment by eduardo....@gmail.com
on 20 Feb 2013 at 8:13
Actually the speed is sent to the MPU and it controls the shutter(curtains)
itself.
So, I believe we wont be able to achieve anything more than 1/4000.
The MPU would not do this.
Original comment by fired...@gmail.com
on 20 Feb 2013 at 12:43
Original issue reported on code.google.com by
doffact...@gmail.com
on 17 Aug 2012 at 9:48