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A720 limits: submit what you know works or doesn't work.

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Offline intrnst

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Re: A720 limits: submit what you know works or doesn't work.
« Reply #20 on: 23 / April / 2008, 19:02:48 »
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I see a few people have downloaded my "readme.txt" file for the A720IS...

Bill, FOA, I'm not an English spoken, be aware of that when you examine this.


CHDK links
==========

If you think on newbies, make it always easy: full pointing links.
Something like...

chdk.wikia.com/wiki/CHDK_in_Brief
(I think it's a good and easy starting point.)

chdk.setepontos.com/index.php/topic,55.0.html
(you should ponder not point to setepontos.com in first moment)




Summary of Items needed to run CHDK (don't worry, details way below):
=====================================================================

6. Consider this suggestion chdk.setepontos.com/index.php/topic,964.0.html


Summary of Process to Load and "boot"/"run" CHDK (details way below):
=====================================================================

If the above, this could be disposable or tool (Card Tricks) oriented.


Detailed instructions (and links) on Loading/Booting CHDK:
==========================================================

2. You may push 4Gb, if Card Tricks

4. If you mention "DISKBOOT.BIN" you must name "PS.FIR"

5. Reconsider if Card Tricks

6. Same as above



Hope this have some use for you.
Thanks

__
PS: This readme.txt, without 720's particularization, may come with the autobuild or build ZIPs.
« Last Edit: 23 / April / 2008, 20:02:36 by intrnst »
-- funny english, be aware -- CHDK for Dummies - The Very First Steps

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Offline BB

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Re: A720 limits: submit what you know works or doesn't work.
« Reply #21 on: 23 / April / 2008, 23:15:54 »
Thank you Intrnst for your suggestions...

I thought about trying to keep the "readme.txt" to exactly what is needed for a new person to load and start up CHDK on an A720IS (really, probably any DRY OS camera).

I stayed away from anything new and changing (like the Card Tricks or trying to run on 8GB+ cards) because these things are still changing and more complex subjects that can always be addressed later (Wiki/Forum).

I did discuss PS.FIR a little bit--but mostly to make sure people did not try to find, load, and start CHDK using the "Firmware Update" method--expressly because it does not work with the A720IS (or any other "Dry OS" camera). This seemed to be a confusing point for about 1/2 the "newbies" I was (hopefully) trying to help.

I also stayed away from links to active forum threads because they tend to grow and talk about things not directly needed by a new user to just get CHDK running.

This file could be changed so that it addresses both WindRiver and Dry OS cameras--but my suggestion was to provide a very simple readme.txt file with no potentially confusing discussions about other cameras or work-a-rounds for limitations (like 4GB max partition). Was also why I stayed with a "Windows" oriented discussion because the other MAC/Linux/etc. instructions were either still a bit difficult for a non-computer user or still changing (also, I really only know/have access to Windows at this time).

In the end, things like "Card Tricks", 8+GB card support and such, in my humble opinion, should be added to the Wiki once they are stable (or even added now with basic information and a pointer back to the main discussion thread in Forums).

Thank you again Intrnst for reviewing my readme.txt file. It is difficult enough for somebody like me (who only knows English) to organize and post my thoughts here--I realize for somebody not speaking English how much work it is for you.

If people think that this readme.txt file is useful and complete as is (or with additions/modifications), I may try to follow your suggested links, Intrnst, and see if I can figure out how to add those to the Wiki (with the author's permissions).

Sincerely,
-Bill
« Last Edit: 24 / April / 2008, 12:11:39 by BB »

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Offline intrnst

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Re: A720 limits: submit what you know works or doesn't work.
« Reply #22 on: 24 / April / 2008, 03:15:17 »
Bill, you're right about stable versions (isn't CHDK a kind of, anyway?), but the appeal of a "non PROMPT all in one" solution for the average user moved my guess.

I agree with you about the 8GB cards, for now.

I think if your project could be as general as possible and help this "first time user", perhaps the trunk admins think the same.

Maybe in a second time each owner could join your project customizing it in various camera flavors.

Keep it moving.
cheers
« Last Edit: 24 / April / 2008, 03:24:58 by intrnst »
-- funny english, be aware -- CHDK for Dummies - The Very First Steps

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Offline intrnst

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Re: A720 limits: submit what you know works or doesn't work.
« Reply #23 on: 25 / April / 2008, 03:58:57 »
Thank you Intrnst for your suggestions...
...
I also stayed away from links to active forum threads because they tend to grow and talk about things not directly needed by a new user to just get CHDK running.
...

Maybe your way is better...

CHDK End-User's Guide
-- funny english, be aware -- CHDK for Dummies - The Very First Steps


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Offline BB

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Re: A720 limits: submit what you know works or doesn't work.
« Reply #24 on: 25 / April / 2008, 10:50:46 »
Thank you for your kind words Intrnst.

The PDF manual is a very good effort, but probably more than a "newbie" needs to get started.

I will go through the readme.txt file and clean up any typos and then check with GrAnd and see if he wants to put in the ZIP file or if I should just go in the Wiki and attach it to one of the getting started topics.

-Bill

Re: A720 limits: submit what you know works or doesn't work.
« Reply #25 on: 02 / May / 2008, 18:37:54 »
I thought about trying to keep the "readme.txt" to exactly what is needed for a new person to load and start up CHDK on an A720IS (really, probably any DRY OS camera).


Bill, many thanks for the excellent readme, it would be great to see this added to the WIKI.

I am a raw beginner (no pun intended ... well only a little) and have struggled a lot with the mass of terminology used (bear in mind that I am an IT consultant so I am not unfamilier with weird terms). Your text file is a useful summary of what is required for an A720 user like myself and I wish that I'd found it before getting started!

Regards, Julian.

Re: A720 limits: submit what you know works or doesn't work.
« Reply #26 on: 03 / June / 2008, 19:41:42 »
Hi,

I just tried out the ISO override.  Can't get it to work for low ISO on my A720.  Tried ISO 40, all indications are that the ISO should be 40, but exposure was unchanged (vs 80), and the image is the same, i.e. no decrease in noise that I can measure.

If someone has got ISO 40 to work on an A720 please tell me how to do it and  how you test that it is working.
Jon

Re: A720 limits: submit what you know works or doesn't work.
« Reply #27 on: 04 / June / 2008, 04:58:55 »
This option does not work as expected on my A720IS either.
As far as I can read, ISO overrride is still an experimental option. HOWEVER, you will not get improved S/N ratio with lower iso than 80 (and I mean market 80) on the A720IS :( . I've done some tests on my A720IS that shows this. If you have a program that can give you picture luminosity as a mean value (photoshop), you can easily test this yourself.  Take pictures in total darkness with fixed shutter speed (Tv or M mode) and enter different ISO values in the ISO overrride menu. Plot the luminosity values  against the ISO values in excel and you will see that the best S/N ratio is at ISO 80.

Remember that the ISO values you enter in CHDK are real ISO values NOT market.

The correlation between real and market ISO values are:

Real = -0,319483 + 0,653908*Market
or
Market = 0,489913 + 1,52926*Real

I don't know if this is too advanced info, but I will be happy to explain further if necessary.

I will try to add my own plot to this post (first time I try to add a picture to a post, hope it works...)




Re: A720 limits: submit what you know works or doesn't work.
« Reply #28 on: 04 / June / 2008, 10:20:16 »
Hi,

Very nice plot.  It seems quite linear.  One question:  How did you develop the raw data?  In-camera?  If so then what ISO did the camera think you were using?
Jon

Re: A720 limits: submit what you know works or doesn't work.
« Reply #29 on: 04 / June / 2008, 14:45:41 »
I did nothing else than set the ISO override value for each picture (JPEGs). The raw data is the returned luminosity mean value when you see data for the picture histogram in Photoshop. I guess you can use any software that can give you a luminosity value for a picture.

The ISO values I used are the ones you see when you enable real and market ISO values in CHDK. The values shown by the Canon firmware are not precise.

 

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