Porting A410 - help wanted - page 5 - General Discussion and Assistance - CHDK Forum

Porting A410 - help wanted

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Offline tired

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Re: Porting A410 - help wanted
« Reply #40 on: 04 / August / 2011, 21:58:17 »
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hi,
I have a question!
The difference between the iso i set in "ISO override" and "ISO raw image report it",Is normal?
exist a Linear tolerances!
override ISO*1.8=Real ISO
50-- -------89
100------180
200------360
300------540
400------721
800-----1445
1600----2890
3200----5783

Thanks.

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Offline reyalp

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Re: Porting A410 - help wanted
« Reply #41 on: 04 / August / 2011, 23:24:41 »
hi,
I have a question!
The difference between the iso i set in "ISO override" and "ISO raw image report it",Is normal?
Yes, canon display is in "market ISO" while override is in "real ISO"
Don't forget what the H stands for.

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Offline srsa_4c

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Re: Porting A410 - help wanted
« Reply #42 on: 05 / August / 2011, 16:18:04 »
Now it's time for me to ask.

I've found out, that - under special conditions - the A410 can do manual focus without crash.
Those conditions are:
- previous call to MFOn() in firmware
- zoom has to be used previously (any position will do, even zooming in a step then zooming out)

Using zoom probably causes something to initialize. If there's no MFOn() call, only some zooming, no crash happens (and setting the focus succeeds) until the shutter button is pressed halfways (shoot_half). As soon as the camera wants to do an AF-scan, it crashes as usual.
MFOn() disables any AF-scan. It works not only on A410, but it also helps on A420 (no unnecessary AF-scan during SD-override). I suspect, some other (older?) models could also use it. I've also found this thread http://chdk.setepontos.com/index.php?topic=321.10 about IXUSes, but found no actual code about using MFOn() and MFOff().
My problem is, that properly implementing this MFOn/MFOff stuff seems very complex:
SD override can be switched on/off
 - using the menu
 - using the keyboard shortcut
 - by loading the config on startup (even in play mode...)
 - ...?
All of the above resides in different parts of the core.

I currently switch on this mode in platform/generic/wrappers.c lens_set_focus_pos(), and switch it off when half-shoot happens and the SD override has already been disabled (in gui.c, couldn't find a better place yet) -> could something like this be included in the official trunk? The code in core is #ifdef'd out of course (#ifdef CAM_NEEDS_MFON_FOR_MF).

I'm waiting some suggestions from the devs like
1) Dont bother, nobody's using these old models anyway  ;)
2) <some suggestion about tracking & managing the state of this mode>
...
« Last Edit: 05 / November / 2011, 15:45:09 by srsa_4c »

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Offline tired

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Re: Porting A410 - help wanted
« Reply #43 on: 05 / August / 2011, 19:53:00 »
hi,
I have a question!
The difference between the iso i set in "ISO override" and "ISO raw image report it",Is normal?
Yes, canon display is in "market ISO" while override is in "real ISO"

Sorry I do not understand.
i read this:
http://chdk.setepontos.com/index.php?topic=138.msg8172#msg8172

ISO i set in camera(override) are:50,100,200,300,400,800,1600,3200
and using Auto CHDK to EXIF v1.3 for check real ISO.
i att. log here.
The results are respectively(for ex:for first image i set ISO value"50" and auto chdk to exif report it 90)
Which is real ISO?{override(50) or composite(90)?}



thanks for beta4. i test video after 17 min say The memory is full! :D


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Offline reyalp

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Re: Porting A410 - help wanted
« Reply #44 on: 05 / August / 2011, 22:43:08 »
The results are respectively(for ex:for first image i set ISO value"50" and auto chdk to exif report it 90)
Which is real ISO?{override(50) or composite(90)?}
The exif value is the "market" value. You'd have to ask Canon why they display a different value than what they use internally. See also http://chdk.setepontos.com/index.php?topic=6396.msg67003#msg67003
Don't forget what the H stands for.

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Offline srsa_4c

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Re: Porting A410 - help wanted
« Reply #45 on: 06 / August / 2011, 14:52:05 »
thanks for beta4. i test video after 17 min say The memory is full! :D
I hope that only means your sd card became full, right?

About ISOs:
According to my preliminary tests the maximum ISO setting that's effective is a little above ISO400, so anything above that has no additional effect. (This is in market ISO, the one you can set in Canon's original menu.)

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Offline tired

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Re: Porting A410 - help wanted
« Reply #46 on: 06 / August / 2011, 19:46:32 »
I hope that only means your sd card became full, right?

Exactly.
test with Lower quality: :D



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Offline srsa_4c

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Re: Porting A410 - help wanted
« Reply #47 on: 07 / August / 2011, 07:13:52 »
OK, thanks for confirmation.


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Offline reyalp

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Re: Porting A410 - help wanted
« Reply #48 on: 07 / August / 2011, 16:14:01 »
[quote author=srsa_4c link=topic=2597.msg71445#msg71445 date=13126567
About ISOs:
According to my preliminary tests the maximum ISO setting that's effective is a little above ISO400, so anything above that has no additional effect. (This is in market ISO, the one you can set in Canon's original menu.)
[/quote]
FWIW, on many cameras the highest ISO you can set in the canon settings is actually something different, done in jpeg processing rather than sensor gain. For example, on my a540, raw from ISO400 and ISO800 are identical.

On more modern cameras, there is often a separate "high iso" or low light mode, which is different again.
Don't forget what the H stands for.

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Offline srsa_4c

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Re: Porting A410 - help wanted
« Reply #49 on: 07 / August / 2011, 17:34:13 »
FWIW, on many cameras the highest ISO you can set in the canon settings is actually something different, done in jpeg processing rather than sensor gain. For example, on my a540, raw from ISO400 and ISO800 are identical.
On more modern cameras, there is often a separate "high iso" or low light mode, which is different again.

I know. But I wouldn't call this old entry level camera "modern", nor would I think they've done something like you described in its firmware. The factory settings for ISO range from ISO 50..200 (for some reason they didn't include the usual ISO 400 setting, maybe some manager found it too noisy :) ). The DNGs I shot show the same difference in brightness as the corresponding jpegs (tested between ISO 50 .. "800", where the "800" setting produced only marginally brighter picture than the 400).

Now the reason I'm here:
Beta 5
- subject distance override / manual focus is now possible
  note: this does not include af-scan in video (which would be too much work to fix)
- movie time limit increase was tested, it's no longer "experimental"
- included philmoz's fix for the vanishing menus

The source patch goes to the usual thread.

Edit:
forgot to fix a typo

Edit2:
- sd override is not able to set focus in the "supermacro" range, it's pointless to use it in that mode
« Last Edit: 08 / August / 2011, 08:37:24 by srsa_4c »

 

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