CHDK firmware hack discussion (13)
Thanks for the reminder.
The problem I recalled was related to the inability to use the auto boot feature on 4 GB cards unless the cards were formated with the non-standard FAT 16. Even then, the FAQ said that the "correct support of such cluster [64K] size is not guaranteed".
As I noted in the wiki docs, you would NOT want to use this script to
shoot 0cm to infinity.
Thanks for clarifying this, Russel.
I did not go into detail examining the script, so I did not realize that what I proposed would trigger thousands of shots. For a 1cm-to-infinity focus stack it would certainly be necessary to exponentially increase the focal steps as the focal point became more and more distant. But I would guess something around 30 steps might be sufficient for such a stack, provided an optimal preset/calculation of focal planes? And certainly not more than 100?
Would it be possible to make a special "x-cm-to-infinity" version of the DOF stack script? If there is room to define a large enough list of hard coded optimal focal distance presets that would probably be the simplest? Or could it be dynamically calculated in the script, using near-plane-distance and number-of-planes as parameters?
I wondered earlier, but didn't ask, why the (one) static filename
instead of writing to a sequential name? Or, a filename derived frorm
the datestamp? I guess the principal use of printing the screen is to
dump the "benchmarks" results page, eh?
I have fine tuned edit_number and the print_screen function.
edit_number. Pressing either MENU or PRINT won't loose the last edits.
print_screen. Following Russel's suggestion there is a choice of the file to
which 'print_screen' writes. The behavior is controlled by the number given
to the FIRST call to 'print_screen'.
First call is either,
'print_screen 0' The text is appended to the last file. If the file
was there already, the text is written at the end and the older
text is not removed.
'print_screen 1' The text is written to "A/CHDK/BOOKS/PS00000.TXT". The
new text overwrites any existing text in the file if there was any .
'print_screen N' The text is written to the next file number. The file
number cycles between 0 and N-1. If the resulting file number is 5,
then the text is written to file "A/CHDK/BOOKS/PS00005.TXT".
The file number of the last written file is kept in file
"A/CHDK/BOOKS/PS_COUNT.TXT". Delete the file to reset the counter.
The file update time is set as expected.
Further calls to 'print_screen' behave as they did before. 'print_screen 0'
turns off writing to the file and 'print_screen 1' turns it back on.
@title printscreen test
@param a None
@default a 0
@param c mode: 0-append, 1-replace, other-modulo c
@default c 1
print "START "c
print "Not written to file"
print "This should be written to the file."
The updates can be found here,
I have tested everything. Please let me know if there is any problem.
I did not go into detail examining the script, so I did not realize
that what I proposed would trigger thousands of shots. For a
You're understanding is clear now, I hope.
The script would snap thousands of shots IF you instructed it to do so.
and more distant. But I would guess something around 30 steps might
be sufficient for such a stack, provided an optimal
preset/calculation of focal planes? And certainly not more than 100?
30 steps? No.
lookit --} http://www.dofmaster.com
The DOF is approx 1mm deep for near distances 0-40mm. You'll need a frame from each of these, then you can begin "cutting corners" further out. (Or just situate your subject at least 40mm away, then those near steps aren't needed.)
That seems reasonable, but I doubt the rulesets for each of the 68 combinations of apertureXfocalLength would fit in an 8Kb script.
Would it be possible to make a special "x-cm-to-infinity" version of
the DOF stack script? If there is room to define a large enough list
of hard coded optimal focal distance presets that would probably be
the simplest? Or could it be dynamically calculated in the script,
using near-plane-distance and number-of-planes as parameters?
If "dynamically calculated" is possible, that's beyond my ability.
Anyone attempting to code this could have the script check get_av and get_tv, but confidence in the values reported being accurate would necessitate using the script only in Manual (ModeDial). In that case, the user would have the burden of pre-metering the scene to choose (lock in) an apertureXshutter combination which would yield the proper exposure.
I think a practical approach would be for you to experiment and collect the datapoints (step values) necessary to create a continuous stack -- twice -- one for your widest zoom setting, and another for full zoom. For both sets, use the same mid-range aperture (I'd suggest f5.0).
From your two resulting scripts (named S3infDOFwide5.bas and 3infDODzoom5.bas for instance) you could further experiment to find out whether the output stack from the scripted set of step values is "still okay" when the script is run with an aperture setting of f4.5, or f5.6. If the stack shows blurred banding (probably will) you can stick with shooting stacks always at Av5.0, or you can pinpoint what/where the datapoints need to be changed to create other aperture-specific scripts.
I've just tested your script (the one on wiki) on my A640. It works perfectly well with the default settings.
It's so easy to import the stack on CombineZm and produce a sharp macro picture ...
Here is my first attempt (quick and dirty ...) on a watch laying on the table :
stacked picture with 20 frames !
I've to play with the CZM parameters in order to reduce sharpening which is somewhat aggressive to my taste ...
Thanks a lot for this nice script
amit goyal wrote:
hi all, i am a new user of s3is, i just read about CHDK firmware,can
i use this firmware and how, is there a risk to use this and from
where i download this and how upload to my S3IS .please tell me in
detail .thanks in advance
No risk as it doesn't really change the firmware in the camera. The program that extends the functions sits on your memory card and must be reloaded every time you boot the camera.
Download instructions are referenced in the first post in this thread.
well said... these guys have provided something canon would never had provided with a great deal of skill and effort that no-one else has managed to do and for FREE and they get belly-aching "why not my cam, I'm going on holiday". Unbelievable.
I think I would put it a bit stronger than this. I do appreciate
that it can be frustrating to not have CHDK for whatever cam you have
(I waited a while for mine) but what we have here is a group of
people putting in a lot of effort and making the results freely
available. I am grateful and impressed (and there is no way I could
have written it). Pleas for "why not mine" just seem out of order.
Anyone know if something like this is going to come out for the S5
with its newer chip?
I've been monitoring various English-language forum sites & haven't read that anyone has attempted a DIGIC III hack.
Is it possible to program this... I mean to make the camera save the raw files directly in Adobe DNG format. It is an open format and it is accepted by every raw processing software.
Or perhaps that would put too much work in the camera processor making raw saving time extremely long?
By the way...GREAT WORK. It has made my A640 a much better camera
I just found that there's a option for noise duction at RAW menu, and if I choose on, it will always intrigue Dark frame substraction for every jpeg shot, even though I don't save raw. The jpeg will alwasy be bad pixel free, just like a pixel mapping did. For those who suffer from hot/stuck pixels problem, I think that's a good solution. the disadvantage, of cousre, a little bit of extra time to process it.
Wow! Thanks for mentioning this !
Because "After dark frame subtract ON/OFF" is shown in the CHDK menu page for RAW settings, I didn't realize this was a global (RAW and jpeg) setting.
I've added a note to the wiki docs explaining this; hopefully the wording is clear:
Note: the "After dark frame subtract" on/off toggle is independent from
the "Save RAW" setting. When dark frame subtraction is set OFF, it is OFF
for jpeg saves as well, and the OFF setting affects jpeg saves regardless
whether or not "Save RAW" is enabled.
Your suggestion to force it ON for all shots (most of the time) sounds good, but I'm actually more excited about having the option to force it OFF. Disabling the in-camera dark frame subtraction will provide a HUGE benefit to me when shooting lightning. I use the long shutter approach (15sec exposure; ISO50; f4.5 approx). With the in-camera noise reduction in effect, shutter open time can only be 44% (or so) of total time... and I still had to post-process all photos through a utility like Cam2pc to get rid of a couple groups of hot pixels that the camera failed to neutralize.
I posted this in its own thread, but I'll try it here. Does anyone know if there's a way in CHDK to keep the LCD from blacking out during flash recharge? A710, specifically.